Assessment & Research

Evaluating contributions of progressive ratio analysis to economic metrics of demand

Lambert et al. (2026) · Journal of the Experimental Analysis of Behavior 2026
★ The Verdict

Basis x PRA gives you equilibrium predictions fast, but skip it if you need true elasticity numbers.

✓ Read this if BCBAs running preference assessments in day or vocational programs for adults with ID.
✗ Skip if Clinicians who only need rank order or who work with young typical learners.

01Research in Context

01

What this study did

Lambert et al. (2026) asked if Basis x Progressive Ratio Analysis (PRA) gives the same demand numbers as full demand curves. They ran repeated PRA sessions with adults who have intellectual disabilities. Each adult worked for snacks while the required button presses grew after every earned bite.

02

What they found

The Basis x PRA scores did not line up with classic elasticity numbers. Yet the same scores did predict where consumption flattened out, called the equilibrium point. Mixed bag: one useful number, one useless number.

03

How this fits with other research

Doughty et al. (2010) saw mixed links between preference ranks and reinforcer power. Lambert’s mixed result echoes that theme: one metric works, one fails.

Kang et al. (2013) reviewed 14 studies and said some tools give clearer reinforcer picks. Lambert adds a new tool—Basis x PRA—that can spot equilibrium but not elasticity, filling a narrow slot.

Bauman (1991) showed delay, not effort, drives demand in rats. Lambert keeps the economic lens but moves it to humans with ID, widening the species map.

04

Why it matters

You now know Basis x PRA can flag when a reinforcer will quit working without building a full demand curve. Save time: run a short PRA, find the break point, and use that number to set session lengths or token costs. Do not expect elasticity values—if you need those, run the full curve.

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Run a five-trial Basis x PRA with one client, note the break point, and set the next token cost just below that number.

02At a glance

Intervention
not applicable
Design
case series
Sample size
96
Population
intellectual disability
Finding
mixed

03Original abstract

Progressive ratio analysis (PRA) has been used to quantify the relative reinforcer efficacy of various programmed consequences across basic and applied research paradigms. It has also been used as an alternative methodology for demand‐curve analysis. In this study, we enrolled 96 consenting adults with disabilities to participate in a translational controlled consecutive case series. Specifically, we compensated participants for using an arbitrary response (e.g., a die roll) to demonstrate the circumstances under which they would work to earn preferred reinforcers in both Basis x PRA and progressive fixed ratio analysis (PFRA) paradigms. Using t tests of logarithmically transformed Pearson correlation coefficients, we established that Basis x PRA did not correlate with metrics of demand elasticity obtained from PFRA. However, Basis x PRA significantly predicted multiple metrics of equilibrium observed during PFRA. Consequently, the assessment likely retains prescriptive value across a number of domains.

Journal of the Experimental Analysis of Behavior, 2026 · doi:10.1002/jeab.70077