1 Friends or Traders? Do social networks affect the use of market mechanisms by farmers in India Kathy Baylis, Ashwini Chhatre, Satya Prasanna and Tisorn Songsermsawas † Selected Paper prepared for presentation at the Agricultural & Applied Economics Association’s 2012 AAEA Annual Meeting, Seattle, Washington, August 12-14, 2012 This is a preliminary draft. Please do not cite. Copyright 2012 by [Kathy Baylis, Ashwini Chhatre, Satya Prasanna and Tisorn Songsermsawas]. All rights reserved. Readers may make verbatim copies of this document for non-commercial purposes by any means, provided that this copyright notice appears on all such copies. † Tisorn Songsermsawas ([email protected]) is the corresponding author. Kathy Baylis and Ashwini Chhatre are Assistant Professors in Department of Agricultural and Consumer Economics and Department of Geography, and Tisorn Songsermsawas is a PhD student in Department of Agricultural and Consumer Economics at the University of Illinois, Urbana-Champaign. Satya Prasanna is an independent scholar in India.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
Friends or Traders? Do social networks affect the use of market mechanisms by
farmers in India
Kathy Baylis, Ashwini Chhatre, Satya Prasanna and Tisorn Songsermsawas†
Selected Paper prepared for presentation at the Agricultural & Applied Economics
Association’s 2012 AAEA Annual Meeting, Seattle, Washington, August 12-14, 2012
This is a preliminary draft. Please do not cite.
Copyright 2012 by [Kathy Baylis, Ashwini Chhatre, Satya Prasanna and Tisorn Songsermsawas].
All rights reserved. Readers may make verbatim copies of this document for non-commercial purposes by any means, provided
that this copyright notice appears on all such copies.
† Tisorn Songsermsawas ([email protected]) is the corresponding author. Kathy Baylis and Ashwini Chhatre
are Assistant Professors in Department of Agricultural and Consumer Economics and Department of Geography,
and Tisorn Songsermsawas is a PhD student in Department of Agricultural and Consumer Economics at the
University of Illinois, Urbana-Champaign. Satya Prasanna is an independent scholar in India.
2
Friends or Traders? Do social networks affect the use of market mechanisms by
farmers in India
Kathy Baylis, Ashwini Chhatre, Satya Prasanna and Tisorn Songsermsawas†
Abstract
In this paper, we ask when small-scale farmers invest in a long-term contract with a
trader to assist them in selling their cash crops. By investing in a long-term relationship, the
farmer may improve their market information, but they lose the option of selling to other traders
in any specific year. The decision to invest in such a long-term contract may also be affected by
the farmer’s social network: either because social networks can facilitate the communication or
market information to larger number of small farmers, in which case they act as complements
with the long-term contract with a trader, or they can provide an alternate source of market
information and risk pooling, in which case they act as substitutes. We use data from a field
survey which contain detailed information about social networks of 522 households across 17
villages of the Thaltukhod Valley in Himachal Pradesh, India. We first outline how social
networks and long-term contract with a trader might help small-scale farmers in a developing
country market their cash crops. We then estimate the probability of a farmer making such an
investment and find that social networks affect this choice. We find significant peer effects, and
we see evidence that the more central position the household has in the network and the smaller
the network, the higher the probability of such an investment.
This is a preliminary draft. Please do not cite.
† Tisorn Songsermsawas ([email protected]) is the corresponding author. Kathy Baylis and Ashwini Chhatre
are Assistant Professors in Department of Agricultural and Consumer Economics and Department of Geography,
and Tisorn Songsermsawas is a PhD student in Department of Agricultural and Consumer Economics at the
University of Illinois, Urbana-Champaign. Satya Prasanna is an independent scholar in India.
3
Introduction
The transaction costs of marketing cash crops for small agricultural farmers in developing
countries can be substantial (Kirsten and Sartorious 2002, Rujis et al. 2004). Market
intermediaries such as traders can help reduce these transaction costs by disseminating market
information, mitigating risks and supporting commitment (Spulber 1999). Social networks can
also act to reduce transaction costs through facilitating information exchange, risk sharing and
enabling economies of scale (Fafchamps and Minten 1999, Lyon 2000, Fukunaga and Huffman
2009). The purpose of this paper is to investigate the relationship between a household’s social
network and the household’s investment in a long-term contract with a trader to market their
agricultural production in rural northern India. We investigate how the type, diversity and
position in the social network affects the household’s decision to make a specific investment in a
long-term contract with an agricultural trader for their cash crops and whether social networks
act as complements or substitutes to the use of a trader. Further, we consider how both the
traders and social network affect household outcomes.
A primary source of transaction costs is information costs and uncertainty (Coase 1937,
Stigler 1961, 1967). For agricultural farmers in rural India, the sources of transaction costs may
include their lack of access to market information, insufficient knowledge of production
technologies, and the potential decay of unsold cash crops. Traders, on the other hand, can help
the farmers overcome these barriers by facilitating the commercialization of the cash crops and
sharing information about the market (Fafchamps and Minten 1999).
Information can also be shared through social networks. A series of studies on the
adoption of new technologies in agricultural production conducted by Udry and Conley (2001,
2005, 2010) show that social networks can assist the flow of information and subsequently can
4
facilitate adoption of new technologies throughout the network. Although a number of studies
have analyzed the importance of both social networks and traders to the improvement of
economic outcomes in several developing countries, very little quantitative research has been
conducted on the relationship between social networks and trader with regards to the household’s
agricultural commercialization decision. This study seeks to highlight some of the key
components that drive the household’s decision whether to take advantage of their social
networks or to commit to a long-run use a trader to help commercialize their cash crops.
We use social network analysis to derive summary characteristics of social networks,
which encompass several attributes including the size, density and structure of the social network
and household location within the network. Then, using econometric methods informed by
spatial econometrics, we ask what characteristics of the network affect the decision of the
household to establish a long-term commitment to a trader for a specific crop. Thus, we explore
whether the nature of the social network affects the choice investment in a long-term relationship
with a trader and the household outcome. Preliminary results from this analysis indicate that
households with smaller and denser social networks are more likely to have a long-term
relationship with at least one trader. We also find substantial peer effects. The centrality
measure of a household in the network is also a significant indicator of a long-run commitment
to a trader, where the centrality measure indicates how central a household is located within its
network. A central location in a social network leads to an influential role of that node for the
other nodes within the same network. Therefore, if a household that is centrally located commits
to a long-run relationship with a trader, it is more likely that this particular household will be
influential on such commitment of other households within the same network. Moreover,
individual characteristics of households also play an important role in determining the decision
5
to invest in a long-term relationship with a trader. Based on the survey data, there is evidence
that greater wealth, higher education, larger family size and higher altitude of a household might
lead to the decision for households to make a specific investment of establishing a long-run
relationship with a trader to support the sale of their cash crops.
We see three main contributions of this study. To our knowledge, this is the first study to
analyze how detailed information on how each household’s position within a social network
affects their use of a trader. Our measures are not restricted to whether a relationship exists
between two households, but also include the nature, closeness, density and degree of contact
among the households in each village. Although it is natural to assume that a household with
more connected network is more likely to be able to obtain information about a trader and
eventually decides to adopt a trader to help commercialize their crops, we are interested to
investigate this pattern of adoption in greater detail in thus study.
The second contribution is due to the fact that our dataset include all households across
the 17 villages in the Thaltukhod Valley in Himachal Pradesh, India. Since our dataset contains
the entire population in the area of study, we can investigate whether social networks and long-
term contract with a trader act as complements or as substitutes without the limitation of
estimation bias from sampled data.
The third contribution of this study is that this is one of the first studies to apply novel
spatial econometric methods to the study of social networks. We follow the new work by Udry
and Conley (2010) and Banerjee et al. (2011), and apply spatial econometric analysis to
explicitly estimate spatial lags across the social network into account.
2. Literature Review and Conceptual Framework
The theoretical model that we use to develop the conceptual framework for this study
relies heavily on the specific investment model of a firm (Tirole’s 1988). Suppose an agricultural
6
household producer (seller) in northern India has to make a decision on whether to make a
specific investment in a long-term contract (or relationship) with a trader (buyer) to help
commercialize for his cash crops. This specific investment depends on each particular type of
cash crop the producer grows. A long-run relationship with a trader is a specific asset of the
household in that it requires investment of time and trust with a specific trader and does not
directly benefit the household in dealings with other traders (Tirole 1988). In return, a long-term
commitment with a trader ensures the farmer that the trader would regularly supply market
information to him.
The specific long-run relationship between a farmer and a trader comes with both
benefits and drawbacks for both parties. For the farmer, a long-term commitment with a trader
assures consistent demand, eliminates future search cost and guarantees frequent delivery of
market information by the trader. However, such specific relationship prevents the farmer from
taking advantage of occasional price spikes in the market if he were to sell the cash crops on his
own. This situation is referred to as a ‘locked-in’ bilateral trading relationship (Klein et al.,
1978). On the other hand, the specific relationship between a farmer and a trader provides the
trader provides the trader with consistent supply and low price variation. The only cost that the
trader has to incur is only due to the specific investment. This specific investment creates
‘hostage’ by providing incentives for the farmer to stay in this specific relationship (Klein et al.,
1978). Anecdotally, in the Thaltukhod Valley such incentives may include offering rides for the
farmer’s family members to hospitals or assistance with marriage arrangements. These incentives
are extraneous to agricultural production, but they are given by the trader to the farmer in order
to hold the farmer in the specific relationship.
7
The specific relationship generates mutual benefits for the farmer and the trader as long
as they remain active in it. However, if the specific contract is terminated, each party faces
different levels of consequences. The discontinuation of the specific relationship might result in
the farmer’s reduction in demand for cash crop. This might further lead to the risk in crop
spoilage, which is different depending on the type of cash crop grown. On the other hand, the
dissolution of the specific contract would incur extra search cost for the trader to look for a new
trading partner to engage in a long-term contract with. This extra search cost might be very
minimal since there are multiple farmers in Thaltukhod Valley that grow the same type of cash
crop. Therefore, if the long-term specific contract is to be suspended, the party that would always
receive a worse-off outcome is the farmer.
Suppose our theoretical model is such that there are a trader who wants to buy the cash
crop and the producer who grows that cash crop faces a (sunk) transaction cost involved in
getting the good to the trader. Each party has hidden information; pre-harvest, the trader does not
know the true quality or quantity of the cash crop that the producer wants to sell, while the
producer does not know about the market outcome. When there is uncertainty about the quality
of the crop, supply of cash crops or market outcome, the market will not be able to function
efficiently since the trader and the producer have asymmetric information (Akerlof 1970).
Assume that each party is trying to maximize his/her payoffs under uncertainty given the other
party’s hidden information. Processes that can reduce this uncertainty can improve the possibility
of trade, and may increase the price received by the producer (Kherallah and Kirsten 2002). In
other words, a long-term contract between the producer and the trader can provide market
opportunities to the producer and guarantee a regular supply of cash crops to the trader, which he
can use to improve his sale price (Kherallah and Kirsten 2002, Swain 2008). We use this
8
conceptual framework to further develop a model to study the role of traders on the
commercialization of cash crop production in northern India and its implications to the social
networks of an agricultural economy.
The theoretical model that we use as our framework to analyze the long-term specific
relationship between an agricultural farmer in rural northern India is based largely on the model
proposed by Noldeke and Schmidt (1995). First, consider an option contract in which a farmer
and a trader, both risk averse, would together establish a long-term, specific relationship to trade
a cash crop. Before trade, both the trader and the farmer make sunk, specific investments
and . The trader’s valuation of the cash crop is given by and
represents the seller’s cost of production, where represents the state of
nature and is distributed on the region according to the joint density function .
Let and represent the strictly increasing and continuous cost functions for
the specific investments made by the farmer and the trader. Also, let and be
strictly positive and continuous in both arguments. Let denote the level of trade, and
denote the net payment from the trader to the farmer. Then, after trade, the utility levels of the
trader and the buyer can be given as follows.
Following Hart and Moore (1988), this specification of option contract gives the farmer
the right to supply to cash crop to the trader and receive price , or not to supply the cash crop
to the trader and receive market price Intuitively, the farmer will have the incentive to invest
the long-term relationship with the trader if he expects the difference between and to be
smaller than his production cost, and will choose not to invest in such specific investment with
9
the trader and will instead trade at market price if he expects otherwise. The price the
farmer receives from both scenarios can be derived as follows (Noldeke and Schmidt, 1995).
If then
If then .
The expressions for the expected utility of each party can be derived given the farmer’s
investment choice made from the option contract offered to him. Given an option contract
where is the base payment (price received by the farmer if he decides not to make a specific
investment) and is the option price. Moreover, the farmer’s decision to make a
specific investment in a long-term relationship with a trader also depends on the source of
information he chooses to receive market information from. In this scenario, a farmer can either
choose to receive market information from a trader or rely on their social networks for
information Therefore, the expected utility for the trader and the farmer can be given by
Given that trade is the efficient outcome, and the trader receives full marginal return from
his investment, the option contract is one in which the farmer chooses the optimal
investment level to solve the following problem
Although deciding to invest in a specific asset as a long-term commitment to a trader can
generate a substantial level of benefits for the producer, this investment in a specific asset also
10
comes with costs (Williamson 1989, Tirole 1988). A specific investment creates a ‘lock-in’
contract between a seller and a buyer that makes the use of such specific asset invested not as
effective outside the relationship (Williamson 1979). By choosing to invest in this long-term
contract with a trader as a specific asset, the agricultural producer’s outside opportunities are
eliminated due to this specific commitment to a trader. Therefore, a long-term commitment to a
trader provides the agricultural producer with a number of benefits including market information
and consistent flow of demand. However, the specificity of this relationship also burdens the
farmer with costs in a way that it reduces the producer’s market opportunities outside the
relationship.
Most literature on the role of agricultural traders has been concentrated on Africa. Several
studies find that the relationship between traders and small-scale farmers helps to improve
economic outcomes and productivity (Fafchamps 1996, Barrett 1997, Fafchamps and Minten
1999, Fafchamps and Minten 2001, Moser et al. 2005). These outcomes result from a reduction
in the time needed to transport goods and explore market opportunities, better information about
the market, more stable demand and supply, and a reduction in losses from spoilage. The
assistance of traders greatly enhances income opportunities for these small-scale farmers,
reducing uncertainties in the quality and the buyer’s willingness to pay, and in return, given a
fixed amount of transaction cost, the traders with well-connected networks enjoy higher
compensation due to higher sales volume.
In many developing countries, personal relationships play a significant role in daily
economic activities. These social networks are viewed as a form of capital that can foster
cooperation and coordination and generate economic returns (Coleman 1990, Putnam 1993,
Fafchamps 1998, Woolcock 1998, Narayan and Pritchett 1999, Lyon 2000, Fafchamps and
11
Minten 2001, Udry and Conley 2001, Winter-Nelson and Temu 2005, Jackson 2008, Udry and
Conley 2010). As a result, social networks may substitute a market intermediary and reduce the
household’s transaction costs of marketing their production. Conversely, social networks may
enhance the benefit of using a trader, since market knowledge can now spread further, and the
pooling potential of the social network may generate economies of scale for the trader
themselves. Thus, we wish to determine whether social networks and long-term contracts with a
trader are complements or substitutes in the rural Indian farmers’ commercialization process of
their cash crops.
How personal relationships affect economic productivity has been analyzed in recent
years. As discussed extensively in Fafchamps and Minten (1999), familiarity and trust can help
facilitate economic exchange in several regards. Specific functionalities of the social network
can foster better economic outcomes of the small-scale farmers. For example, a social network
can facilitate the transmission of information throughout the network, especially the information
about technology and market opportunities (Kranton 1996, Barr 1997). The broader is the
network, the greater are the sources of information. The adoption of a new production
technology or market mechanism by an individual with a large network is more likely to result in
a significant dispersion of similar adoptions throughout his social networks (Bandiera and Rasul
2006). Due to this crucial role of social network, we are interested in examining the
characteristics of social network with regards to type, diversity and location that could lead to
long-term trader commitment among small-scale farmers in the Thaltukhod Valley.
Despite the various functionalities, social network cannot fully replace a long-term
contract with a trader in some of the roles that traders can perform. Several studies have carefully
analyzed the role of trust between trader and agricultural producers and argue that it greatly
12
fosters cooperation between the parties involved (Coleman 1990, Putnam 1993, Lyon 2000,
Fafchamps and Minten 2002). The adoption of a trader as a middle-person in the transaction of
agricultural products can signal quality of agricultural products to the final buyer because the
trader wants to uphold their reputation with the consumers (Kherallah and Kirsten 2002, Batt
2003, Best et al. 2005). Thus, through reputation, a trader can help reduce uncertainties about
product quality and delivery facing the buyer. The fact that social network, on the other hand, is
a non-market mechanism that relies heavily on personal interactions among small-scale farmers
and likely cannot create the trust and reputation as a trader for the consumer.
Transaction costs play a key role in deciding when to enter a contract (Allen and Lueck
1992, 1999, Canjels 1998). Although social networks can help farmers overcome transaction
costs associated with marketing, there are notable aspects of transaction cost that social networks
alone cannot help reduce. As previously noted, the main sources of transaction costs are
information and uncertainty (Coase 1937). With regards to market information, a trader can only
supply the local farmers with the latest information about the market including policy changes,
technological advances or consumer demand. However, a trader who is in contact with a farmer
who has a large social network can also communicate market information to a number of farmers
through that network. If this is the case, then we have evidence that a long-term contract with
trader and social networks act as complements. On the other land, if a household is in contact
with other households that can obtain information about the market, that household might not see
the need for a long-term contract with a trader. In this scenario, social networks and the long-
term contract with the trader are substitutes.
Transaction cost can also occur from the uncertainty specific to each cash crop and the
supply level of each crop (Goetz 1992, Jayne 1994, Omamo 1998, Key et al. 2000, Winter-
13
Nelson and Temu 2005). There are three main cash crops grown by the local farmers in
Thaltukhod Valley: kidney beans, potatoes and peas. The uncertainty associated with potatoes is
mainly due to disease shocks and storage life. Potato blight largely affects all producers in a
region at the same time, resulting in substantial shocks to supply, causing the price of potatoes
sold to fluctuate greatly over time. The long storage life of the potatoes allows them to be stored
up to two years, allowing retailers to mitigate against these potential supply shocks. A farmer
will neither necessarily know about blight in a neighboring production area, nor how many
potatoes are currently in storage in the primary retail markets. Thus, potato producers do not
observe these key components of expected market price unless informed by a trader.
For peas, the pattern of market price is much more consistent over time than that of
potatoes, with the price being higher in the spring and lower in the summer. The high
perishability of peas implies that they cannot be stored from one season to the next, and disease
shocks are less systematic than in the case of potatoes. However, the high perishability of peas
necessitates the rush to deliver the crop to the market soon after harvest.
Transportation cost plays an important role determining the level of transaction cost
associated with each crop (Eswaran and Kotwal 1986, Key et al. 2000). As potatoes are larger
and heavier than kidney beans and peas, potatoes growers bear higher transaction cost when they
are trying to sell them. Due to the fact that farmers growing each crop face different sources
uncertainty, it is reasonable to investigate the decision of a farmer to make a specific investment
by establishing a long-term relationship with a trader in light of lowering transaction costs and
sharing of risk (Fukunaga and Huffman 2009), and analyze its implications of such specific
investment to his social networks.
14
Few papers have studied the relationship between traders and social networks. Most of
the earliest studies in this area belong to a series of papers by Marcel Fafchamps and Bart Minten
from surveys in African countries (Fafchamps 1998, Fafchamps and Minten 1999, Fafchamps
and Minten 2001). These papers demonstrate that more successful traders are those with larger
social networks. Of the various functionalities can accommodate, these studies have found the
consistency of supply and demand, and the sharing of risk are observed to be most crucial. Social
networks also play an important role in shaping and fostering economic development in rural
Ghana, where the spread of information, capital and influence that determine economic decisions
rely heavily on the social networks of local farmers (Conley and Udry 2001, Conley and Udry
2010). Our paper complements the existing literature by considering the combined effect of
traders and social networks on farmers at the household level. Specifically, we explore how the
context and structure of social networks influence a household’s decision to commit to a long-
term contract with a trader to commercialize their agricultural products.
3. Area of Study and Data
The study area is Thaltukhod Valley, an area of 17 villages and 522 households located in
the Indian Himalayas (as shown in Figure 1). There is a considerable level of variation in the
livelihood strategies of households in the valley. Most households make their living from a
combination of subsistence agriculture, commercial crop cultivation, livestock rearing, and civil
service jobs. The forests that adjoin each village also make significant contributions to livelihood
strategies, as households depend (to varying degrees) on forest products like fuel wood, grazing
area, fodder, timber, fencing, biomass, and medicinal plants. Due to the mountainous landscape
of Thaltukhod Valley, the agricultural areas do not generally span large, continuous areas. Each
village has between two and seven agricultural land units that vary in size and altitude. Within
15
each land unit, there are clear, legally-recognized delineations of what land belongs to each
household in the village, with landholding sizes varying greatly among households. While the
land is privately-owned by individual households, the close physical proximity of properties in
the same land unit incentivizes households to make cooperative crop management decisions.
In 2008, a comprehensive survey was administered to households in these villages.
Households were asked detailed questions about their livelihood activities for the previous four
years (2004-2007), and ten years ago (1998). The survey also collected detailed social networks
of the all households and whether the household has a long-term relationship with a trader and
for which crop. The survey also contains detailed crop information for each household.
According to the data from the survey, all farmers in this region grow one or more cash crops of
potatoes, kidney beans and peas.
Within each village, we observe both households who have a long-term relationship with
a trader and households who do not. Moreover, certain villages are in contact with up to three of
the six traders operating in the region. All of the traders are of higher caste. Thus, we see
evidence that the decision to use of a trader is not purely determined by geography. Traders also
operate in all three crops, implying the choice to use a trader is not driven solely by crop choice.
In this study, we analyze four social networks characteristics of the households all the
villages in Thaltukhod Valley. The variables of interest are degree, k-step reach, average
reciprocal distance (ARD) and eigenvector. The degree, k-step reach and average reciprocal
distance variable can help explain how much information can flow within a network due to its
size, spread, and closeness but they do not fully capture a household’s influence on other
households within the same network. The eigenvector variable specifically captures influence of
a node with respect to all other nodes within the same network since it is a measure of network
16
centrality. To provide a better understanding of the network measurements discussed earlier,
consider the two maps of social networks in village 6, Tegar and village 14, Bhumchayan,
presented in Figures 2 and 3. As a comparison, compare household number 5 in village 6
(labeled as HH5 in Figure 2) and household number 16 in village 14 (labeled as HH16 in Figure
3). Both households are circled in red in the village network maps. Although both households
appear to be centrally located within each network, they have very different values of
eigenvector and two-step reach variables. For the eigenvector variable, the eigenvector value of
household 5 in village 6 is 0.411 whereas that of household 16 in village 14 is 0.226. The
explanation of such difference in eigenvector values is that as the network of village 16 is much
larger than the network of village 6 (because there are more households in village 14 than in
village 6), the degree of influence a central household has on all the other households in a bigger
network is less than that of a central household that belongs to a smaller network. The two-step
reach of these two households is also different. The two-step reach of household 5 in village 6 is
0.371. This figure indicates that within two steps, this household can reach 37.1% of all the
households in this network. On the other hand, in a much denser network as in village 14, the
two-step reach variable of household 16 is 0.969. This means that almost all of the households
within this network can be reached from this household within two steps. To summarize the
difference between the two network variables, we can think of the two-step reach variable as a
measure of pure information flow within a social network. However, the eigenvector variable
mainly captures the influential effects of a node on the other nodes within the same network.
The summary statistics of the social network variables (presented in Table 1) clearly
indicate that households with higher network eigenvectors are more likely to establish a long-
term contract a trader for a long-term contract to help them sell their cash crops. The degree
17
variable, which measures the average number of links, or network contacts, a household has, is
slightly higher among households dealing with a trader. The “k-step reach” variable, which in
this study uses k=2, measures the number of nodes within the network reachable within 2 steps,
has a mean of 0.55 among the households that don’t use a trader and 0.60 among those that do.
This statistic means that 55 or 60 percent of the network are friends of friends.
The average reciprocal distance variable is a measure of closeness of centrality. It
indicates the average shortest possible path length between a node in network and any other
nodes is in the network. We observe almost no difference in this category between those that
don’t use a trader and those who use a trader (0.49 to 0.51). The last network variable of interest
is the eigenvector variable. The eigenvector defines centrality by indicating how connected one
household is to all the other households within the same network. Put differently, the eigenvector
is an indicator of how important a node is in the entire network. Due to this feature, this
measurement can help describe the degree of influence a node has on its neighboring nodes.
Households that are in contact with at least one trader have an average eigenvector of 0.22,
which is only slightly higher than those who do not (0.19). Therefore, given the statistics of
these network variables, there is some evidence that the structure of the social networks has an
impact on the household’s decision to adopt a trader to help commercialize their agricultural
produce.
The summary statistics of the individual characteristics of the households who invest in a
long-run contract a trader and those who do not are presented in Table 1. First, the average
household income of the households that do have a long-run contract with a trader is 22,162
rupees. An average household that works with a trader owns a total land of 8.42 bhigas and a
total livestock of 1.94 units whereas households that do not have a long-run contract with a
18
trader on average own a total land of 8.18 bhigas and a total livestock of 1.82 units. The average
household sizes (head count) between the ones having a long-run contract with a trader (5.75)
and those do not (5.65) are not significantly different. The caste dummy variable also sees a
significantly higher average among the households which are in a long-run contact with a trader
(0.89 as compared to 0.80).
Households that have a long-run commitment to a trader have on average 0.54 stall-fed
cattle while those do not have a long-run have on average a lower amount of stall-fed cattle
(0.46). They also consume on average more purchased energy (LPG and kerosense) than the
households that do not have a long-term contract with a trader (0.67% as compared to 0.26%).
Finally, household that has a long-term commitment to a trader consume own-produced food
slightly fewer months a year (2.95 as compared to 3.02) than households that do not choose to
invest in a long-run commitment to a trader.
Table 2 illustrates the summary statistics of the households classified by the type the cash
crop they grow. Most of the household and social networks characteristics are similar across
households that grow each type of crops, except that there are a few notable differences. Farmers
who grow peas on average own more land than those who also grow kidney beans and potatoes.
Moreover, households that grow potatoes and peas on average own higher number of stall-fed
cattle, purchase more energy (LPG and kerosene), and consume more food from their own
production. Finally, the proportion between farmers of higher caste to those of lower caste is the
highest among those who grow peas. This is not a surprising result since peas were the latest
crop to be introduced to the farmers in Thaltukhod Valley. Since all of the traders working in the
area are of higher caste, farmers that belong to the higher caste have more access to obtain
market information about peas from the traders.
19
4. Estimation Method
In our study to analyze the role of social networks on the long-term adoption of trader in
rural northern India, we first construct a weights matrix to determine the links of the households
within each village. We will then have a total of 17 matrices and will subsequently use these
matrices to generate the network variables for each household.
To construct the weights contiguity matrix used in this study, we use two questions that
were asked regarding the social network within each of the 17 villages in Thaltukhod Valley.
First, each household is asked to name three households within the same village that they are in
contact with most frequently. Further, each household is also asked to name another two
households that they specifically talk about cash crops most frequently. Thus, each household
can list up to the maximum of 5 different households within the same village that they are most
connected with. Due to the fact that in many cases a household nominated the same household
for both questions, we only count whether a household considers another household to be a
neighbor once. The matrix representing social network in each of the 17 villages is a square
binary matrix with elements 0 and 1, with a dimension equal to the number of households in that
village. Each element corresponding to a particular row and column that takes the value of 1
indicates that a household is a neighbor of another household (in terms of trader network),
otherwise 0. Then, after obtaining the weights matrices for all the villages, we obtain the relevant
network variables from these weights matrices.
The household characteristics that we use to create another set of independent variables
in our study can be divided into four categories, economic and wealth conditions, social status,
household size and elevation. The first category, economic and wealth conditions, is represented
by five variables namely ownership of land and livestock and stall-fed cattle, dependence on
20
self-grown food and reliance on purchased energy sources. The first three factors determine a
large proportion of income of the households in the entire Thaltukhod valley and can also
represent economic responsibilities of the household. Land represents the total area of land each
household owns in bighas (1 bigha is approximately 0.2 hectares). Due to the skewed distribution
in the land and livestock variables, these two indicators are transformed into the natural
logarithmic scale for more efficient estimation results. The other two variables, consumption of
self-grown food and dependence on purchased energy reflects the connectivity to the market of a
household. We assume that the more connected a household is to the market, i.e. buy more
energy and food from the market, the more likely that a household would choose to invest in a
long-run contract with a trader to help them commercialize their cash crops.
The second category of variables illustrates the social status of a household through two
variables: education and caste. In construction the education variable, we use the number of
household members who receive education for more than ten years. As discussed in Agrawal and
Gupta (2005), we have also included the variable on the total number of members in a household
in our analysis as well since family size is likely to be correlated to the education level, which is
the variable in the third category. The caste variable is a dummy variable that indicates whether
the household belongs to either a lower caste or a higher caste (0 = lower caste, 1 = higher caste).
The caste system is deeply rooted in the Indian society since the ancient times and still plays a
critical role in determining the important decisions in the way of lives of people in India. As a
result, we are interested whether the caste which a household belongs to has a significant impact
on its decision to engage a trader to help sell the cash crops.
The fourth category is the elevation level of a household. There two main reasons that
support the inclusion this variable into our model. The first is that elevation level can be used as
21
a proxy for transportation costs. If a household is located at a high elevation level, then that
household would have much greater difficulty transporting the cash crops to sell at the market
due to the higher transportation costs and the more time needed to reach the main town area
located at a lower elevation. Due to this reason, these households carry a greater responsibility of
taking care of these larger land areas for agricultural production purposes and as a result keep
them from taking the time to transporting the crops to sell by themselves.
Some of the major data problems that we are likely to encounter when performing any
econometric analyses are multicollinearity, and heteroskedasticity. Regarding heteroskedasticity,
we first run a general OLS regression on all of the regressions presented in Tables 2 and 3, and
compared them with a robust OLS regression to control for heteroskedastic errors. From these
two sets of OLS regressions, we observe that there is no significant difference between the
parameter estimates. To test for multicollinearity problem of the dataset, we ran the variance
inflation factor (VIF) test and the test result suggests that multicollinearity is not a concern in any
of our models.
The econometric model we use to test the likelihood that a household decides to engage a
trader to help them commercialize their products as a function of individual households’
characteristics and their network characteristics is a logistic regression model. Specifically, the
estimation model is of the form:
where represents the average household ’s decision whether to make a long-run investment in
a trader to help commercialize their cash crops or not, is a vector of household level
individual characteristics and is a vector of household’s network characteristics (included
both separately and all together). Additionally, we also estimate the likelihood of a long-term
22
specific contract between a farmer and a trader using the weights matrix, where represents the
k-nearest neighbor (using k=4) weights matrix based on geographical distance between the
households.
Additionally, we suspect that there might be unobserved effects of each crop that might
significantly result in the investment in a long-run contract to employ a trader. Therefore, we
introduce the village fixed effects to the logistic model:
where all other components of model are the same as in equation (1) and represents the crop
fixed effects for each crop (kidney beans, potatoes and peas).
Also, we are also interested in investigating if the unobserved effects within each village
would effect a household’s decision to commit to a trader in the long-run. Therefore, we
introduce a dummy variable for each village into the model. These unobserved effects can
include the existence of paved roads leading from a village to the main town area, among others.
where all other components of model are the same as in equation (1) and (2) and represents
the crop fixed effects for each village ( ).
Further, we are also interested to see if a household’s decision to invest in a long-term
contract depends on the decisions of their peers within the same social networks. To investigate
this hypothesis, we need to implement the spatial econometric procedures which have been
discussed extensively in the existing literature on the applications of spatial econometric
procedures (Paelinck and Klaassen 1979, Anselin 1988). Anselin (2002) highlights some of the
most widely used model specifications in spatial econometric regressions for empirical studies.
23
Two of the most common model specifications are the spatial lag and the spatial error models.
The spatial lag model can be formulated as follows.
where is the vector of observations on the response variable that represents the household ’s
decision whether to make a long-run investment in a trader to help commercialize their cash
crops, is the spatial weights matrix that illustrates the response variables of the neighbors, is
the vector of the independent variables of the households in the model, is the spatial
autoregressive parameter, is the regression coefficient vector and is the vector of error terms.
Moreover, the spatial error model can be formulated as follows.
where all other components of model are the same as in equation (5), and is the spatial
autoregressive parameter. It is necessary to note that if then our model is reduced to the
standard OLS model. However, if there is sufficient evidence for , the results from OLS
estimates are unbiased and consistent, but the error term is wrong and the parameter estimates
are inefficient.
5. Results
The regression results are shown in Tables 3 through 8. The first set of regressions is the
logit regressions of the likelihood of a farmer’s specific investment in a specific relationship with
the trader, which can be seen in Tables 3 and 6. Tables 4, 5, 7 and 8 present the spatial
autocorrelation regressions using the social network and geographical distance (using k=4
nearest neighbors) weights matrices. As with any other binary response regression, the most
useful approach to interpret the estimation results is to interpret the marginal effects of the
model. The marginal effects reported at the mean of the data calculated from the logit regression
24
described in equation (1) are presented in Table 3. In Table 4, we present results from the linear
spatially weighted lag model as defined in equation (5) using the social network weights matrix,
and in Table 5, the geographical distance weights matrix is used. Both Models (1) in Tables 3, 4
and Table 5 are the estimated without any fixed effects. Model (2) in Tables 3, 4 and 5 presents
the econometric estimation with the addition of village fixed effects. Model (3) presents the
results when the crop fixed effects are introduced, and finally in Model (4) we include both crop
and village fixed effects. After we introduce the fixed effects, we observe that the specification
without any fixed effects is not appropriate for our study. The introduction of village fixed
effects allows us to analyze the effects of all other variables in the model on the choice to invest
in a long-term commitment to the trader by removing all the unobserved variations across all the
villages (e.g. size of village). Similarly, the inclusion of crop fixed effects eliminates all the
unobserved variations across the three cash crops.
For the specification of the spatially weighted models, we run the LM specification test
for both spatial lag and spatial error models and the result of the LM test indicates that the spatial
lag model is more likely to be the appropriate specification. We also introduce village and crop
fixed effects to both the logit regression and the spatially weighted regression models. It is
important to note that we are aware of the limitations of the model specification of the linear
spatial lag model. Although our response variable is a binary variable, using the linear spatial lag
model will still yield unbiased coefficient estimates but the error term is inefficient.
The first main result is that social networks affect the decision to invest in a long-term
relationship with a trader. Specifically, different characteristics of a household’s social networks
affect the likelihood of investing in a long-term relationship with the trader in different ways.
The second important finding is that the one’s decision to invest in a long-term commitment with
25
a trader depends on the decisions made by their peers within the same village network. This
result is confirmed by the statistical significance of the spatial autoregressive parameter ( in
the spatial lag regressions. The spatial autoregressive parameter ( is most significant in the
specification that includes both the village and crop fixed effects, as shown in model (4) in Table
4. Thus, we clearly observe that the household’s choice to enter in a long-term contract with a
trader is highly dependent on the crop choice and the actions of their peers in the same network
within the same village. However, in Table 5, the spatial autoregressive parameter is not
statistically significant when the geographical distance weights matrix is used instead of the
social network weights matrix. Third, we observe the effects of the household individual
characteristics that affect the decision to invest in a long-term relationship with the trader namely
ownership of livestock and stall-fed cattle, caste, reliance on purchased energy and consumption
of self-grown food. And finally, the specific characteristics of the choice of crop grown and of
the village largely determine the decision to make a long-term investment in a trader.
Our study investigates the effect of four social network characteristics of households at
the village level across the Thaltukhod Valley. The variables of interest are degree, two-step
reach, ARD and eigenvectors. The degree variable, which measures the number of connections
within the same village network a household has, is statistically significant in some model
specifications, particularly when both the village and crop fixed effects are included. As the signs
of the average marginal effects in the logit regression and the coefficient estimates in the spatial
lag regression are both negative, this indicates that larger number of connections a household
has, the less likely a household would make an investment in a long-term contract with a trader.
This leads us to imply that households are less likely to invest in a long-term contract if their
peers have market information, so there is less need to use the service of the trader. The two
26
other statistically significant variables in our estimation models are the ARD and eigenvector
variables. Although these two variables are not consistently significant throughout all the
specifications, there is enough evidence to conclude that the higher level of closeness (measured
by ARD) and influence (measured by eigenvector) a household is to other households within the
same social networks at the village level, the more likely a household is to invest in a long-term
commitment to a trader for the commercialization of their agricultural produce. This results
presents some evidence that social network characteristics can either be complements (e.g. ARD,
eigenvector) or substitutes (e.g. degree) with the long-term contract with a trader.
Household characteristics also play a significant role in determining the household’s
choice to invest in a long-term contract with a trader. Specifically, these characteristics are the
agricultural responsibilities and the reliance on the market. The ownership of livestock and stall-
fed cattle variables reflect the level of a household’s agricultural responsibilities. Given that
these two variables are statistically significant, though not across all specifications, they indicate
that the household’s opportunity cost of working on their own farm is high. Rather than spending
time to market their cash crops and negotiate prices with different traders, households whose
opportunity cost of own agricultural labor are high would rather choose to invest in a long-term
relationship with a trader. The variables that reflect a household’s reliance on the market are the
proportion of energy purchased from the market (LPG and kerosene) and the consumption of
self-grown food. Although these two variables are not statistically significant for all the models
considered, they highlight that households that have higher level of dependence on the market
more are more likely to make a long-term investment in a contract with a trader. The statistical
significance of the caste variable notes the evidence that households that belong to the higher
27
caste might have better access to the traders since all of the six traders working in Thaltukhod
Valley also belong to the higher caste.
The inclusion of the crop fixed effects yield a very strongly significant result, and
confirms our hypothesis about each crop. The sign of the kidney bean dummy variable is
negative, indicating that farmers who grow kidney beans are less likely to choose to invest in a
long-term commitment with a trader because kidney beans have the least hidden information
among the three crops grown in the region. Potato is the crop with highest transaction cost
among the three, mainly due to its volatile production shocks, market supply and high
transportation costs. Therefore, we see that the average marginal effects in Table 3 and the
coefficient estimates in Tables 4 and 5 of the dummy variable for potatoes to be the most
positive. This indicates that a potato farmer is likely to commit to a long-term contact with a
trader in order to obtain market information about potatoes. Since peas, despite their high chance
of spoilage, have a very consistent price pattern throughout the year, peas growers see less need
of establishing a long-term contract with a trader.
As potatoes and peas are the two cash crops with considerable level of uncertainty
associated, we estimate the likelihood of investment in a long-term contract with a trader among
potato and pea growers. The average marginal effects from this set of logit regressions are
presented in Tables 6, and the coefficient estimates of the spatial lag model are presented in
Table 7 and 8 based on social network and distance weights matrices. Among the potato farmers,
a household’s influence within the network (measured by eigenvector) is the most significant
factor to commit to a long-run contract with a trader. The average marginal effect of the
eigenvector is statistical significant at the 5% level, but the coefficient estimate of this variable in
the spatial lag model is not significant at the 5% level. As for the household characteristics, the
28
statistical significant factors that influence the decision to invest in a long-term contract with a
trader are ownership of livestock, proportion of purchased energy and consumption of own food.
However, the spatial autoregressive parameter in the spatial lag model is not significant for
potatoes growers. This means that there is no strong evidence that peer effects matters in terms
of the investment in the long-term contract with a trader among potato farmers.
Pea growers show a much stronger peer effects of investing in a long-term relationship
with a trader, as shown in the statistical significance of the spatial autoregressive parameter in
Table 6. In this spatial lag model, there is enough evidence to conclude that the ownership of
livestock also affects the decision to commit to a trader in the long-run. Other factors that might
also affect such decision are the ownership of stall-fed cattle and the proportion of purchased
energy used, but they are not statistically significant at the 10% level. The results indicate that
peas grower experience a very strong learning effect from their peers in light of setting up a
long-term contract with a trader. This is a reasonable outcome since peas were introduced to
local farmers in the Thaltukhod Valley recently and farmers might not have sufficient knowledge
and market information about the production of peas.
6. Conclusion
This paper investigates the decision at the household level of small-scale farmers to
invest in a long-term contract with a trader to help them commercialize their cash crops. The data
used in this study comes from a survey conducted of 522 households in 17 villages in
Thaltukhod Valley in Himachal Pradesh, India. We put together a dataset containing the
household level individual characteristics that capture economic conditions, social status,
education level and elevation from the sea level. We also construct network variables that
indicate the type, diversity and position of each household within the social networks of each
29
village from the weights matrix that determine the links between the households. Then, we
perform econometric estimates of the likelihood that each household decides to establish a long-
term contract with a trader to help them sell their agricultural produce based on the individual
household’s characteristics and network indicators.
The main findings from this study can be summarized as follows. First, different
characteristics of a household’s village social network can either perform as complements
(influence, clustering) or substitutes (size) with a long-term contract with a trader as these
network characteristics reflect different levels of exposure to market information for each
agricultural household in each village of Thaltukhod Valley. Second, households’ individual
characteristics such as caste, opportunity cost of agricultural labor and the dependence on the
market consumption have positive correlation with the investment in a long-run contract with a
trader. And most importantly, farmers make the decision to commit to a trader given their crop
choice. Potatoes are more likely to be commercialized through a long-term contract with a trader
due to its high level of uncertainty, while kidney beans are least likely to be marketed through a
trader since they contain the lowest level of hidden information.
The results presented in this paper highlight the importance of social networks that could
potentially lead to the reduction in transaction costs that small-scale farmers in rural India have
to face. Although certain household and network characteristics as described in section 5 of this
study are likely to be more important in determining the decision to commit to a long-run
contract with a trader, we would like to further evaluate to what extent these factors matter.
Moreover, the regression results from the spatial econometric specification also indicate that the
one’s decision to make a specific investment depends on the decisions of farmer’s peers, rather
30
than the geographic distance. In other words, peer effects dominate geographical effects for a
rural Indian agricultural farmer in deciding to invest in a long-term relationship with a trader.
For future work, we plan to examine other household characteristics that could affect the
decision to use a trader. Some of the factors that we are considering to include in our estimation
models include the household level demand for labor in different production activities (forest,
agricultural, construction, and cultural purposes), the access to various local governance
institutions (both governmental and non-governmental), the geographic variables (distance to the
main town, slope and elevation of production plots) and the source of information regarding the
agricultural markets and technical knowledge for each household. We also plan to instrument for
the social network using household geographic proximity and agricultural plot-sharing to address
the network endogeneity. And finally, we plan to use a limited dependent spatial lag model to
obtain more efficient estimation results.
31
References
Agrawal, A. and K. Gupta (2005). Decentralization and pariticipation: The governance of
common pool resouces in Nepal’s Terai. World Development, 33(7), 1101-1114.
Akerlof, G. (1970), “The Market for Lemons: Qualitative Uncertainty and the Market
Mechanism,” Quarterly Journal of Economics, 84(3): 488-500.
Allen, D. and D. Lueck (1992), “Contract Choice in Modern Agriculture: Cash Rent Versus
Cropshare,” Journal of Law and Economics, 35: 367-426.
Allen, D. and D. Lueck (1999), “The Role of Risk in Contract Choice,” Journal of Law,
Economics, and Organization, 15:704-736.
Anselin, L. (1988), Spatial Econometrics: Methods and Models, Dordrecht, The Netherlands:
Kluwer Academic Publishers
Bandiera, O. and I. Rasul (2006), “Social Networks and Technology Adoption in Northern
Mozambique,” The Economic Journal, 116(514): 869-902.
Banerjee, A. et al. (2011), “The Diffusion of Microfinance,” MIT Working Paper.
Barr, A. M. (1997), Social Capital and Technical Information Flows in the Ghanian
Manufacturing Sector, Center for the Study of African Economies, Oxford University,
Oxford, UK.
Barrett, C. (1997), “Food marketing liberalization and trader entry: Evidence from Madagascar,”
World Development, 25(5): 763-777.
Batt, P. J. (2003), “Building Trust in a Filipino Seed Potato Industry,” Journal of Food &
Agribusiness Marketing, 13(4): 23-41.
Berry, S. (1993), No condition is permanent; The social dynamics of agrarian change in sub-
Saharan Africa. Madison, WI: University of Wisconsin Press.
Best, R., S. Ferris and D. Sautier (2005) “Building linkages and enhancing trust between small-
scale rural producers, buyers in growing markets and suppliers of critical inputs,” draft
paper presented at the Beyond Agriculture: Making Markets Work for
the Poor conference, 28 Feb.–1 Mar., London, UK.
Bramoulle, Y., H. Djebbari and B. Fortin (2009), “Identification of peer effects through social
networks,” Journal of Econometrics, 150: 41-55.
Brueckner, J. K. (2003), “Strategic Interactions among Governments: An Overview of Empirical
Studies,” International Regional Science Review, 26(2): 175-188.
32
Canjels, E. (1998), “Risk and Incentives in Sharecropping: Evidence from Modern U.S.
Agricultture,” New York: New School for Social Research, Schwartz Center for
Economic Policy Analysis, Working Paper No. 4.
Chandrasekhar, A. G. and R. Lewis (2011), “Econometrics of Sampled Networks,” MIT
Working Paper.
Coase, R. H. (1937), “The Nature of the Firm,” Economic, 4(16): 386-405.
Coleman, J. (1990), Foundations of social theory. Cambridge, MA: Harvard University Press.
Eswaran, M. and A. Kotwal (1986), “Access to Capital and Agrarian Production Organization,”
Economic Journal, 96: 482-498.
Fafchamps, M. (1998), “Market emergence, trust and reputation,” Stanford, CA: Stanford
University.
Fafchamps, M. and B. Minten (1999), “Relationships and traders in Madagascar,” Journal of
Development Studies, 35(6): 1-35.
Fafchamps, M. and B. Minten (2001), “Property rights in a flea market economy,” Economic
Development and Cultural Change, 49 (2): 229-266.
Fafchamps, M. and B. Minten (2002), “Social capital and the firm: evidence from agricultural
traders in Madagascar,” in C. Grootaert and T. van Bastelaer (eds.), The Role of Social
Capital in Development: An empirical assessment. Cambridge, UK: Cambridge
University Press.
Fukunaga, K. and W. Huffman (2009), “The Role of Risk and Transactions Costs in Contract
Design: Evidence from Farmland Lease Contracts in U.S. Agriculture,” American
Journal of Agricultural Economics, 91(1): 237-249.
Goetz, S. (1992), “A Selectivity Model of Household Food Marketing Behavior in Sub-Saharan
Africa,” American Journal of Agricultural Economics, 73(2): 496-501.
Jackson, M. (2008), Social and economic networks, Princeton University Press.
Jayne, T. (1994), “Do High Hood Marketing Costs Constrain Cash Crop Production? Evidence
from Zimbabwe,” Economic Development and Cultural Change, 42(2): 387-402.
Key, N., E. Sasdoulet and A. De Janvry (2000), “Transactions Costs and Agricultural Household
Supply Response,” American Journal of Agricultural Economics, 82(1): 245-259.
Kherallah, M. and J. F., Kirsten (2002), “The new institutional economics: applications for
agricultural policy research in developing countries,” Agrekon: Agricultural Economics
Research, Policy and Practice in Southern Africa, 41(2): 111-133.
33
Kirsten, J. and K. Sartorious (2002), “Linking agribusiness and small-scale farmers in
developing countries: Is there a new role for contract farming?” Development Southern
Africa, 19(4): 503-529.
Klein, B., R. Crawford and A. Alchian (1978), “Vertical Integration, Appropriable Rents,
and the Competitive Contracting Process," " Journal of Law and Economics, 21:297-326.
Kranton, R. E. (1996), “Reciprocal Exchange: A Self-Sustaining System,” American Economic
Review, 86(4): 830-851.
Lyon, F. (2000), “Trust, networks and norms: The creation of social capital in agricultural
economics in Ghana,” World Development 28(4): 663-681.
Manski, C. (1993). “Identification of endogenous social effects: The reflection problem,”
The Review of Economic Studies, 531-542.
Narayan, D. and L. Pritchett (1999), “Household Income and Social Capital in Rural Tanzania,”
Economic Development and Cultural Change 47(4): 871-897.
Omamo, S. (1998), “Transport Costs and Smallholder Cropping Choices: An Application to
Siaya District, Kenya,” American Journal of Agricultural Economics, 80(1): 116-123.
Paelinck, J. and L. Klaassen (1979), Spatial Econometrics, Farnborough, UK: Saxon House
Putnam R. (1993), Making Democracy Work: Civil Traditions in Modern Italy. Princeton, NJ:
Princeton University Press.
Rujis, A., C. Schweigman, and C. Lutz (2004), “The impact of transport-and transaction-cost
reductions on food markets in developing countries: evidence for tempered
expectations for Burkina Faso,” Agricultural Economics, 31(2-3): 219-228.
Spulber, D. (1999), Market Microstructure: Intermediaries and the theory of the firm. New
York, NY: Cambridge University Press.
Stigler, G. (1961) “The Economics of Information,” Journal of Political Economy, 69: 213-225.
Stigler, G. (1967) “Imperfections in the Capital Market,” Journal of Political Economy, 75: 287-
292.
Tirole, J. (1988), The Theory of Industrial Organization. Cambridge, MA: The MIT Press.
Udry, C. and T. Conley (2001), “Social Learning through networks: The adoption of new
agricultural technologies in Ghana,” American Journal of Agricultural Economics 83(3):
668-673.
34
Udry, C. and T. Conley (2005), “Social networks in Ghana,” in C. Barrett (ed.) The Social
Economics of Poverty: Identities, Groups, Communities and Networks, London, UK:
Routledge.
Udry, C. and T. Conley (2010), “Learning about a new technology: Pineapple in
Ghana,” American Economic Review 100: 35-69.
Williamson, O. E. (1979), “Transaction-Cost Economics: The Governance of Contractual
Relations,” Journal of Law and Economics, 22(2): 233-261.
Williamson, O. E. (1989), “Transaction Cost Economics,” in Handbook of Industrial
Organization, R. Schmalensee & R. Willig (eds.), Vol. 1, Elsevier.
Winter-Nelson, A. and A. Temu (2005), “Impacts of Prices and Transaction Cost on Input Usage
in a Liberalizing Economy: Evidence from Tanzanian Coffee Growers,” Agricultural
Economics, 33: 243-253.
Woolcock, M. (1998), “Social capital and economic development: Towards a theoretical
synthesis and policy framework,” Theory and Society, 8: 53-111.
35
Table 1: Descriptive Statistics (By Trader Use)
Households Housholds
not working with
trader working with trader
Variable Mean Std. Dev. Mean Std. Dev.
Degree 0.2027 0.1464 0.2162 0.1416
Two-step reach
0.5529
0.2788
0.6006
0.2632
Average reciprocal distance
0.4938
0.1412
0.5157
0.1309
Eigenvectors
0.1892
0.1544
0.2208
0.1424
Elevation (meters)
Income (rupees)
Land (bhigas)
Livestock (units)
Stall-fed cattle (number)
2036.13
22161.61
8.1896
0.4882
0.4645
191.771
22259.96
9.7174
0.8472
0.8121
2049.21
25048.17
8.4260
0.6323
0.5498
199.055
50574.21
5.7224
1.1003
0.8132
Purchased energy (%)
0.2559
2.0727
0.6688
4.1038
Own-food consumption (months)
3.0185
1.334
2.955
1.1985
Family size (head count)
5.654
2.3982
5.7621
2.3171
Caste (0=lower, 1=higher)
0.7962
0.4038
0.8842
0.3204
Observations 311 211
Source: Field Household Survey, 2008.
36
Table 2: Descriptive Statistics (By Crop Choice)
Kidney beans Potatoes Peas
Variable Mean Std. Dev. Mean Std. Dev. Mean Std. Dev.