Delay discounting of hypothetical and real money: the effect of holding reinforcement rate constant.

McGeown et al. (2013) asked adults to pick between small money now or bigger money later.

They kept the rate of pay the same for both choices. No one earned faster by taking the small-soon option.

They tested both real dollars and pretend dollars to see if the medium mattered.

When the pay rate was equal, people no longer preferred the quick small amount.

The usual "delay discounting" curve flattened out.

Real money and fake money gave the same flat curve.

García‐Leal et al. (2019) looked at pigeons that had to peck many times during the delay. More pecks raised the birds’ indifference points, so they waited longer. Their study extends the 2013 idea: rate still drives choice, but extra effort can boost later value instead of erasing discounting.

Fortes et al. (2015) also made pigeons work harder mid-delay and saw more self-control. This seems to clash with McGeown et al. (2013), who erased impulsive choice by keeping rate steady. The difference is timing: R held rate constant across options, while Inês raised rate during the delay itself. Same lever, opposite directions.

Reyes‐Huerta et al. (2016) removed numbers and used dots. Like R et al., they wiped out a classic effect (the magnitude effect). Both papers show that tweaking a side variable—rate or format—can make discounting disappear, a tidy conceptual replication.

If you want to see whether a client truly devalues delayed reinforcers, keep the earning speed the same for both choices. Otherwise rate differences will muddy the water. Try giving one token every 30 s no matter which option they pick, then measure preference. This simple guard helps you decide whether to teach waiting skills or just adjust how fast the payoff arrives.