The Effects of Price Changes on Alcohol Consumption in Alcohol-Experienced Rats

This paper reports results of two experiments designed to measure how addicted rats (i.e. laboratory rats with previous ethanol exposure via a variant of the Samson ethanol fading technique) respond to changes in the price of ethanol. For both experiments, rats facing a budget constraint choose between two alternative non-ethanol commodities in a morning control session and between ethanol and a non-ethanol commodity in an afternoon session. The results from both experiments shows that economic models of consumer choice are a useful tool to study ethanol and non-ethanol consumption in rats, and that a history of ethanol exposure did not interfere with rats' ability to behave according to economic theory. In the first experiment, rats responded only moderately to a 100% price increase (especially when compared to the response for the non-ethanol commodity during the control session), but more dramatically for a 400% ethanol price increase. However, going back to baseline prices after a prolonged duration of high ethanol prices yields some evidence that ethanol consumption declines below its original levels. In the second experiment rats responded to increased ethanol prices but not to a cue signaling future price increases. Thus, the experiments provide evidence supporting habit formation but not rational addiction as an explanation of ethanol consumption in rats.