Product life cycle

GEORGE S. DAY

Each of the articles in this special section makes a distinctivecontribution to the long-standing controversy over the mana-gerial value of the product life cycle concept. This overviewis designed to put these articles into a broader perspectiveby analyzing the major issues of identification, forecasting,and strategy formulation encountered in any meaningfulapplication of the product life cycle.

THE PRODUCT LIFE CYCLE:ANALYSIS AND APPLICATIONS

ISSUES

THERE is tremendous ambivalence toward theproduct life cycle concept within marketing. On

one hand, the concept has an enduring appealbecause of the intuitive logic of the product birth—» growth —» maturity —* decline sequence basedon a biological analogy. As such, it has considerabledescriptive value when used as a systematic frame-work for explaining market dynamics.

However, the simplicity of the product life cycleconcept makes it vulnerable to criticism, especiallywhen it is used as a predictive model for anticipatingwhen changes will occur and one stage will succeedanother, or as a normative model which attemptsto prescribe what alternative strategies should beconsidered at each stage. Underlying these criti-cisms are five basic issues that must be faced inany meaningful application of the concept:

• How should the product-market be definedfor the purpose of life cycle analysis?

George S. Day is Professor of Marketing, University ofToronto-

• What are the factors that determine theprogress of the product through the stagesof the life cycle?

• Can the present hfe cycle position of theproduct be unambiguously established?

• What is the potential for forecasting the keyparameters, including the magnitude of sales,the duration of the stages, and the shape ofthe curve?

• What role should the product life cycle con-cept play in the formulation of competitivestrategy?

Each of the articles in this special section pro-vides useful insights into one or more of theseapplication issues. In addition, each article addssupport to the emerging consensus that the productlife cycle represents the outcome or summary ofnumerous forces for change present in the relevantproduct-market, each force acting in concert withothers to facilitate or inhibit the rate of productsales growth or decline. This perspective on thenature of the product life cycle will also guide theanalysis of the application issues in this overviewarticle.

60 / Journal of Marketing, Fall 1981Journal of MarketingVol. 45 (Fall 1981), 60-67.

What Is A Product-Market for thePurpose of Life Cycle Analysis?A problem that confronts all strategy analysis isthe variety of levels of aggregation that characterizehierarchical product structures, ranging from thegeneric product class and industry, to the producttype or form, and down to variants and brands.The extreme positions on the question of appropriatelevel of aggregation for life cycle analysis are: lookat all levels, on the grounds that they each yielddifferent insights, or forget the whole conceptbecause generic product classes serve such enduringneeds that meaningful trends are not usuallyapparent, while product forms are so volatile thatit is difficult to judge with accuracy in which stageof the life cycle the form is or when it will proceedto the next stage (Dhalla and Yuspeh 1976). In-termediate positions include those who argue thatsince managers cannot control product forms orclasses, the analysis must be confined to the brandlevel (Enis, LaGarce, and Prell 1977).

The relevant question is which level best cap-tures the consequences of the underlying forcesfor change. However, there are many dimensionsalong which a product can change. When is a changesufficiently distinct to justify a separate hfe cycleanalysis? One useful answer is proposed by Abell(1980), who defines a product as the apphcationof a distinct technology to the provision of aparticular function for a specific customer group.Only when there is a change along one or moreof these dimensions that involves a sharp departurefrom the present strategies of the participatingcompetitors is a separate hfe cycle necessary. Theadvantage of this heuristic can be seen from itsapplication to problem situations that in the pasthave fueled enduring doubts about the life cycle:

• The timeless consumer product. Was thechairman of Procter and Gamble justified insaying they don't believe in the product lifecycle by citing the case of Tide syntheticlaundry detergent which was introduced in1947 and was still growing in 1976? Duringthe 29-year lifetime, it had undergone 55significant modifications in response tochanges in consumer preferences, laundryhabits, washing machines, and fabrics (Hop-kins 1977). Clearly they have successfullyadapted this product to extended maturitywithout significantly changing either func-tion, technology, or customer.

• The multiple function material. Is there ameaningful hfe cycle for a material such as

nylon, which is subsequently processedfurther to be suitable for different applica-tions such as carpeting, tire cord, and ho-siery? (Levitt 1965) The answer is certainlyno, for each application requires an entirelydifferent strategy. Indeed, it would be moremeaningful to construct a hfe cycle for syn-thetic carpet fibers, for example.

• Technological substitution processes. Untilthe mid-sixties, beverage cans were almostexclusively three-piece steel/tin combina-tions, until two-piece aluminum cans beganto replace them. Then in the mid-seventiestwo-piece steel cans were developed to re-capture the position of steel (Machnic 1980).But during this period, neither the functionsnor the customers of metal cans werechanged. Thus a new product hfe cycle wasnot necessary.

• Sequentially unfolding segments. Some lifecycles are a composite of the sequentialintroduction and development of a basicfunction/ technology within a series of relatedcustomer segments. Cardozo(1979) describeshow a specialized communications systemwas first accepted for process control ap-plications and then extended to security ap-plications within the same adopting firms.After two years a new segment for combinedsecurity and process applications was identi-fied.

As each of these examples demonstrates, prod-uct life cycles summarize the effects of manyconcurrent changes. While these influences mustbe understood, they may not dictate an entirelynew product life cycle.

What Are The Underlying FactorsThat Determine The Parameters of theLife Cycle?

Numerous forces have been hypothesized to in-fluence the sequence and duration of the stages,the shape of the curve, and the magnitude of salesat each transition to a new stage. Past attemptsto validate the existence of the hfe cycle haveuncovered many shapes, durations, and sequences(Buzzell 1966, Cox 1967, PolU and Cook 1969, Rinkand Swan 1979). These efforts have not beenmatched by systematic research into the reasonsfor the difference between shapes. Yet, this knowl-edge is critical to informed forecasting and strategydevelopment. The hmited evidence, however, sug-

The Product Life Cycle: Analysis and Applications Issues / 61

gests that while most of the underlying forces areoperating during several stages, their relativeimportance changes during the transition from onestage to another.

Initial Trajectory StageSome new products, such as industrial robots,diffuse very slowly into their potential market, whileother products virtually bypass this stage. Thedeterminants of the rate of diffusion (Zaltman andStiff 1973) include:

• The perceived comparative advantage of thenew product relative to the best availablealternative.

• The perceived risk, or the subjective estimateby a prospective buyer of the probability ofa negative outcome (Webster 1969). This riskis a joint function of the financial exposurein the event of failure coupled with uncer-tainty as to the outcome. This uncertaintyhas many origins, including an unpredictablerate of technical obsolescence, the unevenquality of early production runs, or a lackof product standardization. Thus, potentialvideodisc buyers may wait to see whethergrooved or grooveless capacitance systemswill dominate solid-state laser systems, sincethe discs are incompatible.

• Barriers to adoption (such as commitmentto existing facilities or incompatibility withexisting values) will slow acceptance evenwhen other factors are supportive.

• Information and availability. Not only mustthe product be readily available (for purchaseand servicing), but the buyer must be awareof the product and informed of the benefits.

Jnßuencing the rate of diffusion. Much of theresearch on diffusion of innovations has dealt withinformation variables and the capacity of formaland informal sources to reduce perceived risk. Thevalue of this work for the purposes of Ufe cycleanalysis is compromised by taking the comparativeadvantages of the product as fixed. In reality theseare conditional variables that can be influenced bythe strategic decisions of both the pioneer firm andthe followers. Thus, manufacturers can invest inpromotion and distribution coverage to increaseawareness, expand sales activity to induce trial,reduce risk by providing technical service, warran-ties and after-sales service support, and enhancethe relative advantage by reducing the deliveredprice or adding new features.

Experience effects. The only systematic consid-

eration of the relationship of strategic decisions andlife cycle consequences has come from analysesof the effect of cumulative industry experience onaverage industry costs. This experience effect isreliably present in high technology industries, wherereal cost declines of 15-30% with each doublingof industry output are consistently encountered(Abell and Hammond 1979, Boston ConsultingGroup 1972, Yelle 1979). Reduced costs shouldeventually lead to lowered prices, which in turnwill improve the comparative advantage of the newproduct. It is a highly interactive effect, for anincreased comparative advantage should acceleratethe rate of acceptance and hence the rate of accu-mulation of experience. Whether this accelerationof demand will materiahze depends on the initialpricing strategies and the persistence of the remain-ing barriers to diffusion.

Other exogenous factors. The early history ofmany new products is shaped by factors beyondthe immediate industry and the potential substitutes.Included in this category are changes in the positionof complementary products and changes in govern-ment regulations and pohcies. For example, thedemand for electronic home entertainment productssuch as television and videodiscs was or is depen-dent on the growth of broadcast capabihties andprogramming. Similarly, the growth of new compu-ter-based office services is contingent on the avai-lability of software. The impact of governmentpolicies can be especially dramatic, for they fre-quently are abrupt events. Consider the impact ondemand for automatic teller machines of a rulingthat these machines are not considered branchesin states where branch banking is not permitted.

The Transition to Rapid Growth

A number of factors, which were latent during theperiod when the initial uncertainties were beingresolved, assume importance as growth accelerates.

Changes in the relationships with substituteproducts. These changes reflect improvements inthe price-performance ratio as experience accumu-lates, designs are improved, new features are added,and the real price declines. This will determine howquickly the new product will replace the substitute,and how much of the volume will be replaced.Substitution will also be triggered by large jumpsin the price of the substitute, as happened in1974-1975 when powdered soft drink mixes grewrapidly at the expense of canned fruit juices, whichhad to absorb large sugar price increases.

Competitive entry strategies. In many product-markets the strategic window seems to open atroughly the same time for most potential entrants.

62 / Journal of Marketing, Fall 1981

First, the initial acceptance of the product helpsreduce the uncertainties that clouded the earlyprospects. This uncertainty may have also en-couraged experimentation with alternative processtechnologies, designs, and marketing strategies. Theresults of these experiments and ongoing marketingresearch reduce the uncertainty to a level that istolerable for larger firms with lower risk profiles—witness recreational vehicles, video games, andsolar heating (Porter 1980). A second incentive isthe widespread belief that it is "easier" to gainshare in high growth markets. The combined impactof many competitors, each investment spending togain a sustainable market position, may createsignificant acceleration in the rate of growth.

The influence of repeat buying. Sooner or latera significant proportion of sales in a product cate-gory will be repeat or replacement purchases. AsMidgeley (1981) shows, the shape of the life cyclecurve can be explained by the ratio of mean adoptiontime (which depends on the duration of the diffusionprocess) to mean interpurchase time. This analysishelps explain why the life cycles for many of thedurable products descnbed by Harrell and Taylor(1981) in this issue exhibit a primary sales cyclefollowed by one or more recycles at a lower levelof sales. In markets with shorter repurchase inter-vals, the repeat buying combines with initial pur-chases as a further source of growth.

Does growth induce growth? As the marketexpands, there are new opportunities for segmenta-tion, and the adaptation of the product or serviceto better fit the needs of customer groups whoserequirements were previously too modest to beserved with a tailored offering. These niches, ofcourse, make the rapidly growing market even moreattractive to prospective entrants.

Evolution to MaturityAs the cumulative sales penetration approaches theultimate market capacity and the growth rate slows,the dominating factor becomes the replacement rate.However, this is not a period of stability, for theultimate potential is frequently an elusive targetand new forces come into play.

Expanding market potential. While the marketcapacity for use or consumption may be stable ona per capita basis, there still could be expansionfrom demographic changes that cause the targetmarket to expand or shrink. At the same time,changes in social or economic trends infiuencingunderlying needs—such as protection against prop-erty theft, or energy conservation—will affect con-sumers' demands for end products such as securitydevices and energy saving products, which filters

back to component suppliers.Buyer learning. This becomes an increasingly

significant factor with repeat buying and the accu-mulation of usage experience. The most generalconsequences are systematic shifts in the elasticitiesor response coefficients. Over the long run, asproducts approach a famihar commodity status,buyers become more price sensitive and less re-sponsive to advertising and promotion efforts eitherby the industry or by individual competitors. Whilethese hypotheses have almost become conventionalwisdom, there is growing evidence of their validity(Erickson and Montgomery 1980).

Competitive turbulence. One version of theproduct Ufe cycle incorporates a distinct competitiveturbulence stage (Wasson 1978), preceding the ma-turity stage. According to this analysis, the slow-down in the growth rate that signals impendingmaturity reveals excess capacity and triggers acompetitive battle for market share. This patternhas been partially corroborated by Boston Consult-ing Group (Conley 1970) analyses of rapid declinesin real prices, triggered by an unexpected economicslowdown, the desire of the pioneer to minimizefurther share erosion, or a major thrust by a newentrant. Despite the importance of these hypothe-sized relationships of changes in price, competitivestructure, and Ufe cycle stage, there is virtuallyno direct empirical evidence. Some indirect supportcomes from the analyses of the PIMS data basereportedbyThorelli and Burnett (1981) in this issue.There is, however, no support for a furtherhypothesis that market shares will stabilize afterthe period of competitive stability. Indeed, Buzzell(1981) has found that mature markets tend to becomeless concentrated as the larger firms lose sharebecause they cannot maintain their initial cost ad-vantage.

The Onset of DeclineOne recent analysis of declining industries (Harrigan1980) observed that there had been virtually noattempt to sort out the factors that influence thestrategic choices managers face during a decline.This study found that some declining environmentswere much more favorable than others in termsof long run sales, profitability, and price stability.Generally, the least favorable environments werethe result of fashion or demographic changes be-cause they were much less predictable than declinescreated by technological change. An importantconclusion was that some declining markets weremore favorable than others if there were pocketsof enduring demand, which could be protected fromincursions by displaced competitors. It may also

The Product LÜ^Í Cycle: Analysis and Applications Issues / 63

prove useful to distinguish a stage of pétrificationfollowing decline if sales stabiUze at some lowerlevel (Michael 1971).

Can The Present Life Cycle PositionBe Unambiguously Identified?The notion of distinct stages, which reflect differentopportunities and threats with respect to marketingstrategy and profit potential (Kotier 1980), is anintegral part of the product life cycle concept. Theusefulness of such analyses is frequently compro-mised by the elusive nature of the boundariesbetween the stages.

Some of the boundary identification problemsstem from the sensitivity of life cycle analyses tothe choice of measures (Wind 1981). Should oneuse unit volume, current or constant dollar totalrevenue, or per capita consumption to measuresales? What adjustments should be made to elimi-nate the effects of economic conditions? Consumerdurables and industrial materials are especially sus-ceptible to changes in economic activity that cancloud the interpretation of the prospects for theproduct.

Further complicating the identification of boun-daries is the variety of possible life cycle patterns.This makes it unlikely that a product's position inits life cycle can be estabhshed simply by observingchanges in the past sales pattern. The imphcationsof the difference between a temporary or even anextended pause in sales growth versus a true toppingout of growth are profound. Thus, one cannot avoidforecasting the future sales path of the product ifsensible judgments about the present life cycleposition are to be made.

What Is The Potential For ForecastingThe Key Parameters of the Life Cycle?The ability of a forecasting model to account forthe driving forces during the various stages of thelife cycle generally determines the accuracy of thepredictions. As support for this assertion we cancontrast the promising track record of diffusionmodels that are suited to the rapid growth stagewith the relative absence of successful forecastingmodels for the maturity and decline stages.

First Purchase Diffusion Models

The most popular models such as the Bass (1969)model, share four distinguishing features (Wind1981):

• a constraint on long run growth within a levelof saturation

• an S-shaped diffusion curve• an assumption about the homogeneity of

consumers• no explicit consideration of marketing deci-

sion variables

When these assumptions are not unduly limiting,and there is sufficient prior sales data to obtainstable parameter estimates (Heeler and Hustad1980), then reasonable forecasts can be achieved.However, the experience of Tigert and Farivar(1981) with optical scanning equipment for super-markets, reported in this issue, suggests this fre-quently is not the case.

Improvements to the forecasting accuracy ofthese models have been sought mainly through theaddition of decision variables (Bass 1980, Dolanand Jeuland 1981, Lillien 1980, Robinson and Lak-hani 1975). However, as Mahajan and MuUer (1979)point out in their review of these efforts, progresshas been piecemeal as the extensions have usuallyincorporated only one decision variable at a time.This is partly a consequence of attempts to makethe model as generally applicable as possible. Judg-ing by the success of the proprietary model devel-oped for analyzing the housewares market, de-scribed by Harrell and Taylor (1981) in this issue,there may be a greater payoff from the developmentof models that incorporate a rich array of marketingvariables but are only applicable to a narrow setof products.

Forecasting Repeat and Replacement Sales

The relationship of the initial purchase rate withthe timing of repurchases dictates both the durationof the rapid growth stage and the eventual shapeof the life cycle curve. Yet, other than work onconsumer nondurables (Ehrenberg 1972), httle isknown of the factors that influence the timing ofrepeat or replacement sales. Even this work is oflimited value for it only applies within estabhshedmarkets where there is no sales trend. However,work by Midgeley (1981) and Harrell and Taylor(1981) provides a promising basis for furtherprogress in this area.

Forecasting the Maturity and Decline Stages

A recent review of the state of strategic planningconcluded that "probably the area in which strategicplanning has performed the poorest is with the wellestabhshed product line that has only averagegrowth . . . what has created disaster for the

64 / Journal of Marketing, Fall 1981

planners is the difficulty in accurately determiningthe maturity of a product, particularly when outsideforces can change that designation almost over-night" (Business Week 1978, p. 68). No single reasonfor the poor forecasting performance has beenosilated, other than the general inability of salesforecasting models to incorporate forecasts ofimportant underlying forces that determine whethera product will stagnate, decline, or revive. Whilemany of these factors are undoubtedly industry-specific, there are numerous variables that havebeen hypothesized to behave as leading indicatorsof the top-out point when product sales growth slowsto the GNP rate (Patel and Younger 1978, Porter1980, Wilson 1969). Unfortunately there has beenno systematic study of the predictive validity ofthese variables.

The essence of forecasting during the declinestage is the recognition that while products providespecific functions, the customers seek the benefitsdelivered by the product. Thus, the rate of declinewill depend on changes in the demand for thebenefits, or the ability of emerging substitute prod-ucts to do a superior job of delivering the benefits.Where the latter threat is dominant the issue isthe rate of penetration by the new product, andthe forecasting problem has come full circle.

The Role of the Product Life Cycle inthe Formulation of StrategyThe derivation of generalized strategic prescriptionsfor each stage of the life cycle has been widelycriticized—and for good reason. Such prescriptionsare bound to be misleading for they assume a singlerole for the hfe cycle as a determinant of strategy,structure, and performance. Unfortunately this roleis implicitly endorsed by a majority of marketingtextbooks through an emphasis on strategic guide-lines appropriate to the various stages. A morerealistic view is that life cycle analysis serves severaldifferent roles in the formulation of strategy, suchas an enabling condition, a moderating variable,or a consequence of strategic decisions.

The life cycle serves as an enabling conditionin the sense that the underlying forces that inhibitor facilitate growth create opportunities and threatshaving strategic implications. Market growth—orthe expectation of growth—enables competitors toenter the market and creates opportunities forofferings directed to segments previously uneco-nomic to serve.

The stage of the life cycle also acts as a moderat-ing variable through its influence on the value ofmarket share position and the profitability conse-

quences of strategic decisions. This role is recog-nized through the inclusion of product growth ratesor life cycle stages as a major dimension in virtuallyall portfolio classification models. Finally, a productlife cycle forecast is not a fait accompli, whichcan only be reacted to, but instead is only oneof several scenarios that are conditional oncompetitive actions.

A Summary Perspective on Strategic RelevanceThe product life cycle is a versatile framework fororganizing contingent hypotheses about appropriatestrategy alternatives {Hofer 1975) and directingmanagement attention toward anticipation of theconsequences of the underlying dynamics of theserved market. To enhance both the descriptiveand explanatory value of the concept, much moreattention needs to be directed toward understandingrecurring patterns of successful strategies organizedaccording to the stages of the life cycle modelsthat are adapted to differences in the importantunderlying forces.

Overview of Papers in the SpecialSectionThis special section was motivated by the continuingcontroversy over whether or how marketing deci-sion makers actually adapt the product life cycleconcept to their needs. Consequently, the emphasisis on empirical papers that address the realities ofidentifying, forecasting, and applying the conceptin a wide variety of contexts.

The first set of four papers is devoted to specificapplications. Harrell and Taylor discuss the validityand strategic value of a model used for assessingnew houseware products. This model supports deci-sion makers effectively because it is built on anintimate understanding of recurring patterns in thehousewares market. The second paper by Quails,Olshavsky, and Michaels complements this bydocumenting the rate at which life cycles have beenshortening in the overall appliance industry. Tigertand Farivar next show that life cycle models canbe effectively adapted to high technology industrialmarkets. Their evaluation of the ability of a modifiedBass model to forecast initial installations of super-market optical scanning equipment clearly showsthat these models can play a significant supportiverote so long as the limitations are recognized. Thefinal paper in the first section by Ayal examinesthe ability of a well-known extension of the lifecycle to explain international trade patterns andfinds that astute strategies by exporters can oftendefeat the predictions.

The Product Life Cycle: Analysis and Applications Issues / 65

The second set of papers deals with thesoundness of the theoretical framework for productUfe cycle analysis. Thorelli and Burnett set the sceneby analyzing characteristic patterns of strategy,structure, and performance over time, using thePÏMS data base for industrial products. Their resultscast into doubt any interpretation of the productlife cycle as a fundamental dependent variableguiding strategic decisions. Midgley then addressesa major gap in life cycle theory by examining theunderlying processes that influence the shape ofthe hfe cycle. The ratio of mean interpurchase timeto mean adoption time is found to be a very usefulforecasting variable.

An important theme linking all the papers in

this special section is the need to incorporate theunderlying factors and processes within the particu-lar market situation into the life cycle model. Sprolesdemonstrates the value of this perspective byproposing an integrated theory of short and longrun fashion acceptance. Finally, Tellis and Crawfordshow that this adaptive view of the hfe cycle isindeed consistent with comprehensive theories ofbiological evolution and that the deterministic life-death analogy so often used in marketing is wrong.

While each paper in this special section makesa distinctive contribution, the cumulative impactof all these papers on the quality of thinking abouta fundamental element of marketing theory shouldbe much greater than the sum of the parts.

REFERENCESAbell, Derek F. (1980), Defining the Business: The Starting

Point of Strategic Planning, Englewood Cliffs NJ: Pren-tice-Hall.

, and John S. Hammond (1979), Strategic MarketPlanning: Problems and Analytical Approaches, Engle-wood Cliffs NJ: Prentice-Hall.

Ayal, Igal (1981), "International Product Life Cycle: ARe-Assessment and Product Policy Implications." Jour-nal of Marketing, 45 (Fall).

Bass, Frank M. (1969), "A New Product Growth Modelfor Consumer Durables," Management Science, 15 (Jan-uary), 215-227.

(1980), 'The Relationship Between DiffusionRates, Experience Curves, and Demand Elasticities forConsumer Durable Technological Innovations," Journalof Business, 53, 551-567.

Boston Consulting Group (1972), Perspectives on Experience,Boston: Boston Consulting Group.

Business Week (1978), "The New Planning," {December18), 62-68.

Buzzell, Robert D. (1966), "Competitive Behavior andProduct Life Cycles," in New Ideas for SuccessfulMarketing, John Wright and Jac Goldstucker, eds.,Chicago: American Marketing Association.

(1981), "Are There 'Natural' Market Structures?"Journal of Marketing, 45 (Winter), 42-51.

Cardozo, Richard N. (1979), Product Policy: Cases andConcepts, Reading. MA: Addison-Wesley.

Conley, Patrick (1970), "Experience Curves as a PlanningTool," IEEE Spectrum, 1 (June), 63-68.

Cox, William Jr. (1967), "Product Life Cycles as MarketingModels," Journal of Business, 40 (October). 375-384.

Dhalla, Nariman and Sonya Yuspeh (1976), "Forget theProduct Life Cycle Concept." Harvard Business Review,54 (January/February), 102-112.

Dolan, Robert J. and Abel P. Jeuland (1981), "ExperienceCurves and Dynamic Demand Models: Implications forOptimal Pricing Strategies." Journal of Marketing, 45(Winter). 52-73.

Ehrenberg, A. S. C. (1972), Repeat Buying, London: North-Holland.

Enis, Ben M , Raymond LaGarce, and Arthur E. Prell (1977),"Extending the Product Life Cycle." Business Horizons,20 (June), 46-56.

Erickson, Gary and David B. Montgomery (1980), "Measur-ing the Time-Varying Response to Market Communica-tion Instruments," in David B. Montgomery and DickR. Wittink, Market Measurement and Analysis, Cam-bridge: Marketing Science Institute.

Harrell, Stephen G. and Elmer D. Taylor (1981), "Modelingthe Product Life Cycle for Consumer Durables," Journalof Marketing, 45 (Fall).

Harrigan, Kathryn Rudie (1980), "Strategies for DecliningInáustúes,'^ Journal of Business Strategy, I (Fall), 20-34.

Heeler. Roger M. and Thomas P. Hustad (1980). "Problemsin Predicting New Product Growth for Consumer Dura-bles," Management Science, 26 (October). 1007-1020.

Hofer, Charles W. (1975). "Toward a Contingency Theoryof Business Strategy," Academy of Management Journal.18 (December), 784-810.

Hopkins, David S. (1977), Business Strategies for ProblemProducts, New York: Conference Board.

Kotier, Philip (1980), Marketing Management: Analysis,Planning and Control, 4th edition, Englewood Cliffs, NJ:Prentice-Hall.

Levitt, Theodore (1965), "Exploit the Product Life Cycle,"Harvard Business Review, 43 (November-December),81-94.

Lillien, Gary L. (1980), "The Implications of DiffusionModels for Accelerating the Diffusion of Innovation,"Technological Forecasting and Social Change, 17. 339-351.

Machnic. John A. (1980), "Multi-Level Versus Single-LevelSubstitution: The Case of the Beverage Can Market,"Technological Forecasting and Social Change, 18, 141-̂149.

Mahajan, Vijay and Eitan Müller (1979). "Innovation Diffu-sion and New Product Growth Models in Marketing."Journal of Marketing, 43 (Fall), 55-68.

Michael, George C. (1971). "Product Pétrification: A NewStage in the Life Cycle Theory," California ManagementReview, 9 (Fall), 88-91.

66 / Journal of Marketing, Fall 1981

Midgley, David F. (1981), "Toward a Theory of the ProductLife Cycle: Some Testable Propositions," Journal ofMarketing, 45 (Fall).

Patel, Peter and Michael Younger (1978), "A Frame ofReference for Strategy Development," Long RangePlanning. 11 (April), 6-12.

Polli, Rolando and Victor Cook (1969), "Validity of theProduct Life Cycle," Journal of Business, 42 (October),385-400.

Porter, Michael E. (1980), Competitive Strategy: Techniquesfor Analyzing Industries and Competitors, New York:The Free Press.

Quails, WiUiam, Richard Olshavsky. and Ronald E. Michaels(1981). "Shortening of the PLC—An Empirical Test,"Journal of Marketing, 45 (Fall).

Rink. David R. and John E. Swan (1979), "Product LifeCycle Research: A Literature Review." Journal of Busi-ness Research. 78 (September). 1\^-1A1.

Robinson, B. andC. Lakhani(1975), "Dynamic Price Modelsfor New Product Planning," Management Science, 21(June). 1113-22.

Sproles. George B. (1981), "Analyzing Fashion Life Cycles:Principles and Perspectives," Journal of Marketing, 45(FaU).

TeUis, Gerard J. and C. Merle Crawford (1981), "AnEvolutionary Approach to Product Growth Theory,"

Journal of Marketing, 45 (Fall).Thorelli, Hans B. and Stephen C. Burnett (1981), "The

Nature of Product Life Cycles for Industrial GoodsBusinesses," Journal of Marketing, 45 (Fall).

Tigert. Douglas and Behrooz Farivar (1981), "The BassNew Product Growth Model: A Sensitivity Analysis fora High Technology Product," Journal of Marketing. 45(Fall).

Wasson, Chester R. (1978), Dynamic Competitive Strategyand Product Life Cycles, St. Charles, IL: ChallengeBooks.

Webster, Frederick E., Jr. (1969), "New Product Adoptionin Industrial Markets: A Framework for Analysis,"Journal of Marketing, 33 (July), 35-39.

Wilson, Aubrey (1969), "Industrial Marketing Research inBritain." Journal of Marketing Research. 6 (February),15-28.

Wind, Yoram (1981). Product Policy: Concepts, Methods,and Strategy, Reading, MA: Addison-Wesley.

Yelle, Louis E. (1979), "The Learning Curve: HistoricalReview and Comprehensive Survey," Decision Sciences,10, 302-328.

Zaltman, Gerald and Ronald Stiff (1972), "Theories ofDiffusion," in Consumer Behavior: Theoretical Sources.Scott Ward and Thomas S. Robertson, eds. EnglewoodCliffs, NJ: Prentice-Hall.

r Keep Currentwith these books

Macromarketing: A Canadian PerspectiveDonald N. Thompson, Patricia Simmie, LouiseHeslop, and Stanley J. Shapiro, eds.318 pages $8/Members $12/NonmemhersThis book is the proceedings of the Third Tri-ennial Canadian Marketing workshop held atYork University, Toronto, in June 1979, wherethe meetings focussed on macromarketing in aCanadian context and included the areas ofconsumerism, consumer protection, legislationand public policy and its impact, social indica-tors, social issues and the non-legislative regu-latory process. Revised from the oral presenta-tions given, these papers reflect the discussionsheld at the conference and cover a broad rangeof topics. There is a short introduction to eachpaper in both English and French.

Marketing Education: Current Status And AView For The 198O'sPatrick E. Murphy and Eugene R. LaczniakMonograph Series No. 11. 106 pages$5/Members $7/NonmembersA baseline study of current practices in mar-keting education, this new monograph will beof great interest to all concerned with existingand future trends in marketing education. Pre-senting the results of a survey of 225 marketingdepartment chairs, this book provides data onundergraduate, graduate and doctoral pro-grams and includes selected abstracts from pastEducators' Proceedings and some journal articles.

To order these two books contact: Order De-partment, American Marketing Association,250 S. Wacker Drive, Chicago, IL 60606,(312)648-0536.

The Product Life Cycle: Analysis and Applications Issues / 67