AbstractIn many political systems legislators face a fundamental trade‐off between allocating effort to constituency service and to national policy‐making activities, respectively. How do voters want their elected representatives to solve this trade‐off? This article provides new insights into this question by developing a conjoint analysis approach to estimating voters’ preferences over their legislator's effort allocation. This approach is applied in Britain, where it is found that effort allocation has a significant effect on voter evaluations of legislators, even in a political system where other legislator attributes – in particular, party affiliation – might be expected to predominate. This effect is nonlinear, with voters generally preferring a moderate balance of constituency and national policy work. Preferences over legislator effort allocation are not well‐explained by self‐interest or more broadly by instrumental considerations. They are, however, associated with voters’ local‐cosmopolitan orientation, suggesting that heuristic reasoning based on underlying social dispositions may be more important in determining preferences over representative activities.