Efficient bilateral taxation of externalities

We consider the quadratic voting mechanism (Lalley and Weyl in Quadratic voting. Working paper, University of Chicago, 2015; Weyl in The robustness of quadratic voting. Working paper, University of Chicago, 2015) and focus on the incentives it provides individuals deciding what proposals or candidates to put up for a vote. The incentive compatibility of quadratic voting rests upon the assumption that individuals value the money used to buy votes, while the budget balance/efficiency of the mechanism requires that the money spent by one voter by redistributed among the other voters. From these assumptions, we show that it follows that strategic proposers will have an incentive to offer proposals with greater uncertainty about individual values. Similarly, we show that, in an electoral setting, quadratic voting provides an incentive to propose candidates with polarized, non-convergent platforms.