Consumption-leisure tradeoffs in pigeons: Effects of changing marginal wage rates by varying amount of reinforcement.
Free rewards plus lower earned payoff cut work and intake, just like a negative-income-tax effect.
01Research in Context
What this study did
Green et al. (1987) worked with pigeons in a closed economy. The birds had to peck a key to earn food.
The team then gave half the usual earned food for free. They watched how the birds changed their work and eating.
What they found
When free food showed up and earned food dropped, the pigeons pecked less and ate less.
The birds acted like people on a negative-income-tax program: less work, less total food.
How this fits with other research
Bachman et al. (1988) extends this idea. Those birds faced rising fixed-ratio costs instead of free food. They still cut energy by eating faster and cooling their bodies at night.
Attwood et al. (1988) used fixed versus progressive ratios. Their pigeons also tracked overall payoff, not just immediate effort.
Together the three studies show pigeons run an energy budget. They adjust work, intake, and even body heat when the payoff drops.
Why it matters
Your clients may also work less when extra free rewards appear. Check if outside reinforcers are diluting your program. Before adding free items, test if task engagement falls. If it does, tighten the contingency or raise the quality of earned rewards to keep responding strong.
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02At a glance
03Original abstract
Pigeons' rates of responding and food reinforcement under simple random-ratio schedules were compared with those obtained under comparable ratio schedules in which free food deliveries were added, but the duration of each food delivery was halved. These ratio-with-free-food schedules were constructed so that, were the pigeon to maintain the same rate of responding as it had under the simple ratio schedule, total food obtained (earned plus free) would remain unchanged. However, any reduction in responding would reduce total food consumption below that under the simple ratio schedule. These "compensated wage decreases" led to decreases in responding and decreases in food consumption, as predicted by an economic model of labor supply. Moreover, the reductions in responding increased as the ratio value increased (i.e., as wage rates decreased). Pigeons, therefore, substituted leisure for consumption. The relationship between these procedures and negative-income-tax programs is noted.
Journal of the experimental analysis of behavior, 1987 · doi:10.1901/jeab.1987.47-17