Delay preference in intertemporal choice: Sooner or later OR faster or slower?

Intertemporal choices are conventionally conceived as decisions about whether to be better off sooner or later. As a reflection of this, most experimental research on the topic has been restricted to choices between single-dated outcomes: One sooner, the other later. Even these decisions, however, can be conceived in a different way: As choices between an option that accumulates faster to its total outcome, and an option that accumulates more slowly to its total outcome. To empirically distinguish between these two interpretations, the experimental design must include options with multiple-dated outcomes, that is, outcome sequences. We report an experiment that includes choices involving outcome sequences as well as choices between single-dated outcomes, where the outcomes are monetary losses, or payments. This design allows us to evaluate a sooner-or-later model and a faster-or-slower model on their ability to predict single-payment choices once calibrated on payment-sequence choices (model generalizability). Moreover, people differ considerably in their preferences for the timing of losses, which we turn to our advantage by evaluating the models on their ability to associate preferences for the timing of multiple payments, as inferred from payment-sequence choices, with preferences for the timing of a single payment, as observed in single-payment choices (parameter generalizability). For that purpose, we develop the classic criteria of convergent validity and discriminant validity in the assessment of construct validity as criteria in the assessment of model validity. The results of a fully Bayesian analysis strongly favored the faster-or-slower model over the sooner-or-later model.