Money now, or more money later?
You'll make 27 choices between a smaller amount of money today and a larger amount after a delay. The amounts and delays vary; there are no right answers and no tricks; just answer honestly, as if the money were real.
Your pattern of choices reveals your discount rate: how quickly a reward loses its pull as it moves into the future.
The science
Would you rather have $54 today or $55 in 117 days? Almost everyone takes the $54; a dollar isn't worth a four-month wait. But push the numbers around and a personal signature emerges: the rate at which future rewards lose their subjective value. Behavioural economists model this with a hyperbolic curve, V = A / (1 + kD): the parameter k is your discount rate, and it varies across people by more than a thousand-fold (Mazur, 1987; Kirby et al., 1999).
This test is Kirby's Monetary Choice Questionnaire, the field-standard 27-item instrument. Your choices are compared against ten candidate discount rates, and you're assigned the rate that best reproduces your decisions, along with a consistency score showing how well a single rate describes you.
Steep discounting is one of behavioural science's most robust correlates of real-world impulsivity: a meta-analysis of 46 studies found reliably steeper discounting in people with addictive disorders (MacKillop et al., 2011), and discount rates predict outcomes from credit-card debt to medication adherence. Shallow discounting (patience) tracks saving, exercise, and educational attainment (Odum, 2011).
Honest caveats
The money here is hypothetical. Reassuringly, studies comparing hypothetical and real rewards find similar discounting patterns, but the stakes are still imaginary and your k should be read as an estimate, not a diagnosis. Discount rates also shift with context (poverty, scarcity and even mood steepen them), so this is a snapshot, not a fixed trait.
- Kirby, K. N., Petry, N. M., & Bickel, W. K. (1999). Heroin addicts have higher discount rates for delayed rewards than non-drug-using controls. Journal of Experimental Psychology: General, 128(1), 78–87.
- Mazur, J. E. (1987). An adjusting procedure for studying delayed reinforcement. In Quantitative Analyses of Behavior, Vol. 5.
- MacKillop, J., et al. (2011). Delayed reward discounting and addictive behavior: A meta-analysis. Psychopharmacology, 216, 305–321.
- Odum, A. L. (2011). Delay discounting: I'm a k, you're a k. Journal of the Experimental Analysis of Behavior, 96(3), 427–439.