Carrie L. Morris
Washington University School of Medicine
Campus Box 8505
4444 Forest Park Avenue
St. Louis, MO 63108
NBER Working Papers and Publications
|September 2008||Measuring intertemporal preferences using response times|
with Christopher F. Chabris, David Laibson, Jonathon P. Schuldt, Dmitry Taubinsky: w14353
We use two different approaches to measure intertemporal preferences. First we employ the classical method of inferring preferences from a series of choices (subjects choose between $X now or $Y in D days). Second we adopt the novel approach of inferring preferences using only response time data from the same choices (how long it takes subjects to choose between $X now or $Y in D days). In principle, the inference from response times should work, since choices between items of nearly equivalent value should take longer than choices between items with substantially different values. We find that choice-based analysis and response-time-based analysis yield nearly identical discount rate estimates. We conclude that response time data sheds light on both our revealed (choice-based) preferences...
|August 2008||Individual Laboratory-Measured Discount Rates Predict Field Behavior|
with Christopher F. Chabris, David Laibson, Jonathon P. Schuldt, Dmitry Taubinsky: w14270
We estimate discount rates of 555 subjects using a laboratory task and find that these individual discount rates predict inter-individual variation in field behaviors (e.g., exercise, BMI, smoking). The correlation between the discount rate and each field behavior is small: none exceeds 0.28 and many are near 0. However, the discount rate has at least as much predictive power as any variable in our dataset (e.g., sex, age, education). The correlation between the discount rate and field behavior rises when field behaviors are aggregated: these correlations range from 0.09-0.38. We present a model that explains why specific intertemporal choice behaviors are only weakly correlated with discount rates, even though discount rates robustly predict aggregates of intertemporal decisions.
Published: Christopher Chabris & David Laibson & Carrie Morris & Jonathon Schuldt & Dmitry Taubinsky, 2008. "Individual laboratory-measured discount rates predict field behavior," Journal of Risk and Uncertainty, Springer, vol. 37(2), pages 237-269, December. citation courtesy of