This paper deals with the analysis and evaluation of sales forecasts of managers, given that it is unknown how they constructed these forecasts. The goal of this study is to find out whether these forecasts can be considered as rational. To examine this rationality, we argue that one has to approximate how the managers could have generated the forecasts. We describe several ways to construct these approximate expressions. The analysis of a large set of managers’ forecasts for sales and pharmaceutical products leads to the conclusion that there are various avenues for improving managers’ forecasts.