The influence of time of day on decision fatigue in online food choice experiments

Purpose Fatigue effects related to answering a sequence of choice tasks have received much scrutiny in the stated choice experiments (SCE) literature. However, decision fatigue related to the time of day when respondents answer questionnaires has been largely overlooked in this literature even though time of day related fatigue effects are well known in the psychology literature. The purpose of this paper is to hypothesize that variations in the time of day when respondents answer an online food choice experiment will translate into observable fatigue effects in the food choices. Design/methodology/approach An empirical SCE concerning food choices is conducted using a web-based questionnaire for interviews in a pre-recruited online panel of consumers. Timestamps collected during the online interviews provide knowledge about the time of day at which each respondent has answered the survey. This information is linked with knowledge from a food sociology survey on typical meal times as well as biophysical research linking food intake to blood sugar and mental energy in order to generate a proxy variable for each respondent’s level of mental energy when answering the food choice tasks in the questionnaire. Findings Results show evidence of a time of day effect on error variance in the stated food choices as well as the subsequently estimated market share predictions. Specifically, respondents provide less consistent answers during the afternoon than at other times of the day. Originality/value The results indicate that time of day can affect responses to an online survey through increased fatigue and correspondingly less choice consistency. Thus, especially online surveys might account for this in data analysis or even restrict accessibility to the online survey for certain times of day.