Counting on my vote not counting: Expressive voting in committees

•We model a committee voting whether to approve an ethical, but costly proposal.•If the proposal is passed, only members who vote for receive expressive payoff.•Reducing the probability of being pivotal raises the share of votes in favour.•A laboratory experiment with a charitable donation framing supports these results.•Structural estimation recovers depth of reasoning, altruistic, and expressive payoffs. How do voting institutions affect incentives of committees to vote expressively? We model a committee that chooses whether to approve a proposal that some members may consider ethical. Members who vote for the proposal receive expressive utility, and all members pay a cost if the proposal is accepted. Committee members may have different depths of reasoning. Under certain sufficient conditions, the model predicts that features that reduce the probability of a member being pivotal – namely, larger committee size, or a more restrictive voting rule – raise the share of votes in favour of the proposal. A laboratory experiment with a charitable donation framing presents evidence in line with these results. Our structural estimation recovers the distributions of altruistic and expressive preferences, as well as of depth of reasoning, across individuals.