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E&F Talk Aniol Llorente-Saguer (Queen Mary) Weighting Votes: Rule Complexity and Information Aggregation

The department for Economics & Finance is happy to welcome Aniol Llorente-Saguer from Queen Mary University London.

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Speaker: Aniol Llorente-Saguer (Queen Mary University London)

Title: Weighting Votes: Rule Complexity and Information Aggregation

Abstract: Committees typically decide through voting. One of the challenges of the voting mechanism is to aggregate information when committee members have different quality of information. In such an environment, more complex rules allow voters to better aggregate information by endogenously allocating more decision power to members with better information.

We consider two polar examples of voting rules in terms of complexity: majority voting and continuous voting.

Under majority, members can simply vote in favour of the proposal, against it or they can abstain. Due to its coarseness, this system does not allow voters to properly express the quality of their information: it either ignores information of poorly informed or it attaches the same weight to votes form highly informed.

Under continuous voting, instead, voters have incentives to choose the optimal weights that implements the efficient decision for any information structure. The desirable properties of this additional flexibility might be overturned by the cognitive costs to deal with the additional complexity.

We test this using laboratory experiments, in which subjects vote with the two rules under different environments. We also study participants’ preferences over the mechanism used. Our main experimental results are the following.

First, continuous voting does better than majority voting on average, but this difference is not always significant and it is significantly lower than theoretically predicted.

Second, under continuous voting, voters with intermediate information quality attach too much weight on their votes.

Third, communication makes these differences disappear. And fourth, despite the higher average welfare under continuous voting, participants are equally split in their support for it.