Assessment & Research

The case against Allen's generalization of the matching law.

Houston (1982) · Journal of the experimental analysis of behavior 1982
★ The Verdict

Allen’s neat matching equation fails math tests on paired schedules, so add bias terms or use maximizing models instead.

✓ Read this if BCBAs who run concurrent-schedule assessments or teach matching law to staff.
✗ Skip if Clinicians only using simple DRA with no concurrent choices.

01Research in Context

01

What this study did

Houston (1982) wrote a math check on Allen’s power-function version of the matching law.

The paper shows the formula breaks when two schedules are paired or shown at the same time.

No kids, no pigeons—just equations and logic.

02

What they found

The proof says Allen’s form cannot describe choice when reinforcers overlap.

In plain words, the pretty curve does not fit real concurrent schedules.

03

How this fits with other research

Mellitz et al. (1983) stepped in next year. They offered a hill-climbing rule that lets momentary maximizing create matching without a separate law. Their model bypasses the algebra problem Houston (1982) exposed.

Hall (1992) tested kids in a classroom token system. Matching appeared only when reinforcer quality was equal. That boundary echoes I’s warning that the simple equation needs extra terms.

Schenk et al. (2020) and Johnson et al. (2009) both found the generalized matching equation fits basketball shot data. These field studies seem to contradict I’s critique, but they use undermatching and bias parameters—exactly the looseness I said Allen’s tight power form lacks.

04

Why it matters

When you plot concurrent-schedule data, do not trust a single power curve. Check for undermatching, bias, and quality differences. If the numbers drift, add parameters or switch to a maximizing model like Mellitz et al. (1983). This keeps your assessment honest and your treatment recommendations solid.

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→ Action — try this Monday

Graph your client’s concurrent-schedule data, add a bias parameter, and re-calculate fit before picking the next reinforcement ratio.

02At a glance

Intervention
not applicable
Design
theoretical
Finding
not reported

03Original abstract

Allen (1981) claims to have established the formal validity of a power-function generalization of the matching law. This paper argues that Allen's proof is not correct when schedules are presented in pairs and that his initial assumptions are too restrictive when all schedules are simultaneously available.

Journal of the experimental analysis of behavior, 1982 · doi:10.1901/jeab.1982.38-109