In the past, the marginal value theorem (MVT) has been successfully applied to animals foraging for food, but no attempts have been made to apply it to human food foraging behavior in the patch context of supermarkets. Based on the MVT, this study established simplified predictions about the quantitative relationship between gain in Euro and patch residence time well as the relationship between travel time between patches and patch residence time.
N = 190 participants were interviewed about their current shopping context at a German supermarket and gave estimates on their travel time, patch residence time and gain. A subset was selected consisting of n = 61 participants who mainly shopped at that supermarket, traveled straight from home and back instead of shopping on the way somewhere else, and traveled by foot. An asymptotic model was fitted to their estimates on patch residence time and gain via nonlinear regression. The resulting model predictions on their economical travel times were compared to participants’ estimates. Reported gains and patch residence times generally showed the relationship predicted by the model with a tendency towards overmatching. The observed relationship between reported patch residence times and travel times showed some differences to the model predictions. Using participants’ estimates instead of measuring time and gain might have been too inaccurate a basis for the model predictions. Interindividual differences in gain and cost functions may be observed and cost factors such as exhaustion may need to be taken into account in future studies.