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A Search for Structural Breaks in Agriculture Economy since Independence Anirudh Jayaraman Exploring for Breakpoints Objective Motivation Data and Methodology Bai and Perron (2003) Technique Data Summary A Search for Structural Breaks in Agriculture Economy since Independence Mid Term Progress Anirudh Jayaraman 1 1 M.Sc Economics Indira Gandhi Institute of Development Research October 14, 2016
32

Agricultural Economics Mid Term Progress Submission

Apr 13, 2017

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Page 1: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

A Search for Structural Breaks in AgricultureEconomy since Independence

Mid Term Progress

Anirudh Jayaraman 1

1M.Sc EconomicsIndira Gandhi Institute of Development Research

October 14, 2016

Page 2: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Outline

1 Exploring for BreakpointsObjectiveMotivation

2 Data and MethodologyBai and Perron (2003) TechniqueData

3 Summary

Page 3: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Outline

1 Exploring for BreakpointsObjectiveMotivation

2 Data and MethodologyBai and Perron (2003) TechniqueData

3 Summary

Page 4: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Objective

Has the Agricultural Sector undergone any significantstructural changes since Independence?

After ’91 reforms?

Need to search for crucial turning points in agriculturalproductivity... CROP WISE.

The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.

Page 5: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Objective

Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?

Need to search for crucial turning points in agriculturalproductivity... CROP WISE.

The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.

Page 6: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Objective

Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?

Need to search for crucial turning points in agriculturalproductivity...

CROP WISE.

The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.

Page 7: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Objective

Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?

Need to search for crucial turning points in agriculturalproductivity... CROP WISE.

The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.

Page 8: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Objective

Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?

Need to search for crucial turning points in agriculturalproductivity... CROP WISE.

The results may be useful for understanding performancetrends for different crops.

This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.

Page 9: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Objective

Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?

Need to search for crucial turning points in agriculturalproductivity... CROP WISE.

The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.

Page 10: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Outline

1 Exploring for BreakpointsObjectiveMotivation

2 Data and MethodologyBai and Perron (2003) TechniqueData

3 Summary

Page 11: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Issues and Motivation

Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.

These turning points are often considered uniformlyacross states, agro-climatic zones and crops.

It may be possible that different crops underwentsignificant structural changes in different years.

Break dates may also end up changing with more recentdata becoming available.

A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.

The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.

Page 12: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Issues and Motivation

Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.

These turning points are often considered uniformlyacross states, agro-climatic zones and crops.

It may be possible that different crops underwentsignificant structural changes in different years.

Break dates may also end up changing with more recentdata becoming available.

A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.

The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.

Page 13: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Issues and Motivation

Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.

These turning points are often considered uniformlyacross states, agro-climatic zones and crops.

It may be possible that different crops underwentsignificant structural changes in different years.

Break dates may also end up changing with more recentdata becoming available.

A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.

The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.

Page 14: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Issues and Motivation

Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.

These turning points are often considered uniformlyacross states, agro-climatic zones and crops.

It may be possible that different crops underwentsignificant structural changes in different years.

Break dates may also end up changing with more recentdata becoming available.

A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.

The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.

Page 15: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Issues and Motivation

Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.

These turning points are often considered uniformlyacross states, agro-climatic zones and crops.

It may be possible that different crops underwentsignificant structural changes in different years.

Break dates may also end up changing with more recentdata becoming available.

A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.

The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.

Page 16: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Issues and Motivation

Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.

These turning points are often considered uniformlyacross states, agro-climatic zones and crops.

It may be possible that different crops underwentsignificant structural changes in different years.

Break dates may also end up changing with more recentdata becoming available.

A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data. The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.

Page 17: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Outline

1 Exploring for BreakpointsObjectiveMotivation

2 Data and MethodologyBai and Perron (2003) TechniqueData

3 Summary

Page 18: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Bai and Perron (2003)

This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + ui

Assume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.

The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.

Underlying Model (m breakpoints)

yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)

Page 19: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Bai and Perron (2003)

This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + uiAssume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.

The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.

Underlying Model (m breakpoints)

yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)

Page 20: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Bai and Perron (2003)

This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + uiAssume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.

The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.

Underlying Model (m breakpoints)

yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)

Page 21: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Bai and Perron (2003)

This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + uiAssume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.

The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.

Underlying Model (m breakpoints)

yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)

Page 22: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Outline

1 Exploring for BreakpointsObjectiveMotivation

2 Data and MethodologyBai and Perron (2003) TechniqueData

3 Summary

Page 23: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Data

The data has been obtained from Data Bank onAgriculture and Allied Sectors in the PlanningCommission website and is sourced from Directorate ofEconomics and Statistics (DES) and Ministry ofAgriculture.

Yield data of principal crops (All-India) since 1950.These are some 26 crops including rice, wheat, jowar,bajra, maize, pulses (disaggregated), cotton, sugarcane,jute, etc.

Page 24: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

Data

The data has been obtained from Data Bank onAgriculture and Allied Sectors in the PlanningCommission website and is sourced from Directorate ofEconomics and Statistics (DES) and Ministry ofAgriculture.

Yield data of principal crops (All-India) since 1950.These are some 26 crops including rice, wheat, jowar,bajra, maize, pulses (disaggregated), cotton, sugarcane,jute, etc.

Page 25: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

To conclude...

Intend to explore for breaks endogenously in agriculturaltime series data.

Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.

Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.

Outlook

Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.

Page 26: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

To conclude...

Intend to explore for breaks endogenously in agriculturaltime series data.

Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all.

∴ look at breaksin yields of principal crops for more granular level detail.

Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.

Outlook

Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.

Page 27: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

To conclude...

Intend to explore for breaks endogenously in agriculturaltime series data.

Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.

Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.

Outlook

Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.

Page 28: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

To conclude...

Intend to explore for breaks endogenously in agriculturaltime series data.

Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.

Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.

Outlook

Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.

Page 29: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

To conclude...

Intend to explore for breaks endogenously in agriculturaltime series data.

Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.

Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.

Outlook

Based on break-dates, one can build further hypothesesas to what might have caused those breaks.

It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.

Page 30: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Exploring forBreakpoints

Objective

Motivation

Data andMethodology

Bai and Perron(2003)Technique

Data

Summary

To conclude...

Intend to explore for breaks endogenously in agriculturaltime series data.

Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.

Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.

Outlook

Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.

Page 31: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Appendix

For FurtherReading

References I

R. Chand.Temporal and Spatial Variations in Agricultural Growthand Its Determinants.Economic and Political Weekly, vol XLVII No.s 2627:55–64, 2012.

Jushan Bai and Pierre PerronComputation and Analysis of Multiple Structural ChangeModels.Journal of Applied Econometrics, 18:1–22, 2003.

Madhusudan Ghosh.Structural Breaks and Performance in Indian Agriculture.Indian Journal of Agricultural Economics, 65(1):1–21,2010.

Page 32: Agricultural Economics Mid Term Progress Submission

A Search forStructuralBreaks inAgricultureEconomysince

Independence

AnirudhJayaraman

Appendix

For FurtherReading

References II

Zeileis et al.strucchange: An R Package for Testing for StructuralChange in Linear Regression Models.CRAN Project, 2005.

Oehmke and Schimmelpfenning.Quantifying Structural Change in US Agriculture: TheCase of Research and Productivity.Journal of Productivity Analysis, 21:297–315, 2010.