Reward density and variable-interval schedule performance in an open economy

There is no general agreement regarding the form of the relation between re sponse rate and reinforcement rate when single schedules of reinforcement a re studied in an open economy. The present study assessed die form of this relation using reward density, which incorporates both reinforcement rate a nd duration of access to food, as an independent variable. Reward density w as manipulated with 4 pigeons by changing the value of the variable-interva l schedule, the hopper duration, or both. The relations between response ra te and reward density were sharply rising and hyperbolic in 3 of 4 pigeons, replicating results obtained by Catania and Reynolds (1968). Because eatin g efficiency was lower in conditions that provided longer hopper durations, programmed reward densities differed from obtained reward densities. When response rates were examined as a function of obtained reward densities, th e same relations were demonstrated more strongly. In further clarifying the relation between response rate and reward density in an open economy, thes e results lend support to the conclusion that open and closed economies yie ld different behavioral effects.