Stated preference techniques and consumer choice behaviour

This PhD thesis examines the way in which individuals make choices during statedpreference experiments (commonly referred subsets of which are called stated choicemethods, conjoint analysis and trade-off analysis). Stated preference experiments askrespondents to rank, rate or choose between different product/service options, whichare made up of a number of attribute mixes. The responses made by individualswithin these experiments allow researchers to estimate consumer preferences.This thesis traces the historical background of stated preference experiments, from thefield of utility theory and experimental economics. An understanding of thishistorical background explains the reliance by practitioners on the assumption thatrespondents make rational choices during the stated preference experiment (where allthe information presented to them within the experiment is traded off in order to cometo an overall preference). In light of considerable research evidence within the fieldof psychology that consumers do not do not conform to this economic concept ofrational choice, and recent criticisms within recent stated preference literature, thisthesis identifies the choice strategies employed by respondents during three statedpreference experiments, where attributes were represented in different ways.Choice based stated preference experiments designed as the context for this research,measure consumers preferences for a newly developed fuel-efficient vehicle, withattributes currently unavailable in the marketplace. The experiments were presentedto respondents as a series of choices between the newly developed vehicle andanother currently available in the marketplace, described in terms of a number ofattributes. The experiments were implemented using `think-aloud' protocol to allowthe identification of respondent's choice strategies.The research successfully identifies the choice strategies employed by respondentsduring the stated preference experiments, and in support of recent criticisms withinstated preference literature, finds significant deviations from the economic concept ofrational choice. Furthermore, significant differences between the choice strategiesemployed by respondents are identified between the experiments where theappearance of the vehicles is represented in different ways. Using response data thatis simulated to mirror the respondent choice strategies identified in each of the threestated preference experiments, the research tests the implications of these choicestrategies on the estimation of consumer utility models. The research identifiessignificant differences between the parameter estimates derived from responsessimulated assuming different choice strategy profiles. The research also identifiessignificant improvements in the estimated parameter values when the identifiedchoice strategies are used in the analysis of the response data, rather than using theassumption of rational choice as an approximation. This suggests that statedprelcrence practitioners might improve model estimation by identifying the choicestrategies used by respondents to inform the analysis of stated preference responsedata.