An analysis of discounting model selection methods: Assessing the generalization of discounting models
Use leave-one-out cross-validation with multilevel modeling to pick the best discounting model—especially when the Rachlin hyperboloid is on the table.
01Research in Context
What this study did
Bailey et al. (2025) ran computer simulations to test which statistic best picks the true discounting model.
They compared AIC, BIC, and leave-one-out cross-validation (LOOCV) under many fake data sets.
Each fake set came from a known model, so the team could see how often each statistic chose the right one.
What they found
AIC, BIC, and LOOCV all found the real model most of the time.
LOOCV paired with multilevel modeling gave the lowest cross-validation error when the Rachlin hyperboloid was in play.
If you fit discounting curves, LOOCV with multilevel is the safest pick.
How this fits with other research
Bigby et al. (2009) asked the same question for IOA algorithms: which one gets you closest to the truth? Their answer was “it depends,” because no algorithm won every time. Bailey’s team got a clearer win for LOOCV, showing model choice can be more straightforward than IOA choice.
Kubina et al. (2022) also looked at analyst tools, but for graphs instead of equations. They found ratio graphs beat linear ones for speed and agreement. Bailey’s paper extends that theme—better tools give faster, cleaner decisions—now for model fit instead of visual trend.
Chang et al. (2024) and Zhi et al. (2023) compared acquisition criteria in single-case designs. Like Bailey, they ran systematic replications to refine measurement rules. All three studies push the same bottom line: small changes in how we score data can save time without hurting accuracy.
Why it matters
If you plot delay-discounting curves for adults or kids, you need to pick between the hyperboloid, exponential, or other forms. Use LOOCV with multilevel modeling and you are less likely to pick the wrong curve. That means cleaner data stories and better treatment decisions when reward timing matters.
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02At a glance
03Original abstract
How the subjective value of an outcome changes as a function of time, probability, or effort has been an active area of psychological and economic research for decades. The exact functional form of how a commodity is discounted has been debated, and there have been numerous forms proposed. One of the challenges when trying to determine the functional form of discounting data is how models are compared, what modeling methods are used, how many data points are used, and what comparison metrics were used. Thus, we sought to replicate and extend previous research comparing discounting model selection methods by simulating discounting data from five functional forms: the Mazur hyperbolic model (Mazur, 1987), Rachlin hyperboloid (Rachlin, 2006), Myerson-Green hyperboloid (Myerson & Green, 1995), Samuelson exponential model (Samuelson, 1937), and beta-delta model (Laibson, 1997). With each of these models we manipulated the number (i.e., density) of data points, used two forms of modeling, and assessed the degree to which each model generalizes to data it has not used in the fitting process. Model comparisons were conducted using the Akaike information criterion (AIC), Bayesian information criterion (BIC), and leave-one-out cross validation (LOOCV). In general, AIC, BIC, and LOOCV selected the correct model, whereas the Rachlin model had the lowest error across folds of LOOCV when relying on multilevel modeling.
Journal of the Experimental Analysis of Behavior, 2025 · doi:10.1002/jeab.70015