One consideration that must be kept in mind when interpreting price effects such as those discussed throughout this article is that these effects are not based on natural experiments. For example, no data are available comparing the amounts of alcohol consumed by individuals or groups at different prices, with all other variables held constant. Instead, researchers use cross-sectional data, which measure consumption for individuals or groups at a given moment in time, or time series of such cross-sectional analyses from more than 1 year. And although investigators in these studies attempt to control for as many confounding variables (i.e., variables that may be correlated with price and consumption) as possible, these efforts can never be complete. These caveats place limits on the ability to infer cause-and-effect relationships from the study findings.
