An Acquired Taste: Rational Decision- Making and Marijuana Initiation Derek Kreager, Penn State & Ross Matsueda, University of Washington June 2007

Matsueda, Kreager, & Huizinga (2006) Bayesian learning and perceptions of risk – Individuals update risk perceptions based upon past behavior and prior exposures to sanctions – Risk perceptions relate directly to future delinquent behavior Baseline Risk Updated Risk Delinquent Behavior New Information

Testing Second Order Hypotheses Moving beyond first order assumptions (i.e., Subjective Expected Utility maximization) Second Order Questions – What forces shape endogenous preferences (i.e. tastes) and perceptions? – How do preferences and future intentions arise in social interaction? – What are the mechanisms for cognitive transformation?

Gary Becker’s (1996) Extended Utility Model “Forward-looking behavior may still be rooted in the past, for the past can exert a long shadow on [present] attitudes and values” (p. 139) Utility maximization based upon endogenous preferences Preferences formed from acquired personal and social stocks Provides an opportunity to integrate economic and social theory

Gaining a Taste for Pot Adolescent marijuana initiation Howard Becker’s (1953) Interactionist Perspective – Marijuana preferences arise in social interaction – Perceptions of uncertainty are transformed into perceptions of pleasure Peer-provided definitions and encouragement Learned inhalation techniques and drug exposure Reflected appraisals of pharmacological effects

Testing An Integrated Approach Predicting initiation and continuation of marijuana smoking Predicting changes in perceptions

Marijuana Initiation in the DYS Yearly survey of 1531 High Risk Denver youth Waves 1-5, ages 10-21

Predicting Initiation Cox Proportional Hazard Model

Changes in Excitement after Initiation Most initiates have low prior perceptions of excitement Many increase perceived excitement upon first use, but sizeable minority maintain zero level

Predicting Excitement Change Change-Score OLS Regression (N=153)

Predicting Marijuana Continuation Structural Equation Model of Binary Outcome (N=214) Coolness Excitement Risk Continued Marijuana Updated Perceptions Pharmacological Effect Impulsivity Friends’ Marijuana Age at Initiation.20*.30*.29*.38*** -.16*.22**.29***.37*** -.17*

Conclusions and Future Research Support for integrated approach – Sequential model of perceived utility – Perceptions of coolness distinguish initiators from abstainers, while perceptions of excitement distinguish continuers from desisters – Marijuana perceptions likely change upon exposure – Peers and pharmacology as change mechanisms – Definitions of marijuana as “exciting” predict continued use and the formation of marijuana preferences Does the meaning of marijuana change after prolonged exposure? How about property crime? Policy Implications