Pré-publication, Document de travail: Using the American and the French time-use surveys, we examine whether people have a preference for a more diversified mix of activities, in the sense that, everything else equal, they experience a higher level of well-being when their agenda is multi-activity, rather than concentrated on a very small number of activities. This could be due to decreasing marginal utility, as is assumed for the consumption of goods, if each episode of time is conceived as yielding a certain level of utility per se. However, in the presence of returns to specialization, people would face a trade-off between the efficiency of specialization and the taste for diversity, as concerns time arrangements. We test these hypotheses and investigate potential gender differences with regard to these patterns.