Auction politics: Party competition and expansionary election promises

Party competition sometimes resembles an auction, where parties seek to 'buy' elections through promises of economic largesse. In this article, I argue that whether parties engage in this practice will depend on political circumstances, such as the level of ideological competition. Incentives to promise more to voters will also vary depending on a party's electoral prospects: for parties that expect a significant level of government responsibility, promising too much is a risky strategy. I test these arguments by focusing on the spending commitments in party manifestos from 20 countries over the period 1945-2017. In line with expectations, parties tend to make more expansionary election pledges when ideological competition is more muted. In addition, left-wing parties' spending commitments are found to be influenced by their projected seat shares (based on opinion polls from before the start of the election campaign) relative to their competitors. Specifically, the stronger a left-wing party's electoral prospects, the more fiscally conservative it tends to be, and vice versa.