This paper investigates the determinants of political polarization, a phenomenon of increasing relevance in Western democracies. How much of polarization is driven by divergence in the ideologies of politicians? How much is instead the result of changes in the capacity of parties to control their members? We use detailed internal information on party discipline in the context of the U.S. Congress—whip count data for 1977–1986—to identify and structurally estimate an economic model of legislative activity in which agenda selection, party discipline, and member votes are endogenous. The model delivers estimates of the ideological preferences of politicians, the extent of party control, and allows us to assess the effects of polarization through agenda setting (i.e., which alternatives to a status quo are strategically pursued). We find that parties account for approximately 40% of the political polarization in legislative voting over this time period, a critical inflection point in U.S. polarization. We also show that, absent party control, historically significant economic policies would have not passed or lost substantial support. Counterfactual exercises establish that party control is highly relevant for the probability of success of a given bill and that polarization in ideological preferences is more consequential for policy selection, resulting in different bills being pursued.

In a large-scale controlled trial in collaboration with the reelection campaign of an Italian incumbent mayor, we administered (randomized) messages about the candidate's valence or ideology. Informational treatments affected both actual votes in the precincts and individual vote declarations. Campaigning on valence brought more votes to the incumbent, but both messages affected voters' beliefs. Cross-learning occurred, as voters who received information about the incumbent also updated their beliefs on the opponent. With a novel protocol of beliefs elicitation and structural estimation, we assess the weights voters place upon politicians' valence and ideology, and simulate counterfactual campaigns. (JEL D12, D72, D83)

We find that regulators can implement identical rules inconsistently due to differences in their institutional design and incentives, and this behavior may adversely impact the effectiveness with which regulation is implemented. We study supervisory decisions of U.S. banking regulators and exploit a legally determined rotation policy that assigns federal and state supervisors to the same bank at exogenously set time intervals. Comparing federal and state regulator supervisory ratings within the same bank, we find that federal regulators are systematically tougher, downgrading supervisory ratings almost twice as frequently as do state supervisors. State regulators counteract these downgrades to some degree by upgrading more frequently. Under federal regulators, banks report worse asset quality, higher regulatory capital ratios, and lower return on assets. Leniency of state regulators relative to their federal counterparts is related to costly outcomes, such as higher failure rates and lower repayment rates of government assistance funds. The discrepancy in regulator behavior is related to different weights given by regulators to local economic conditions and, to some extent, differences in regulatory resources. We find no support for regulator self-interest, which includes “revolving doors” as a reason for leniency of state regulators.

We explore the role of charitable giving as a means of political influence. For philanthropic foundations associated with large US corporations, we present three different identification strategies that consistently point to the use of corporate social responsibility in ways that parallel the strategic use of political action committee (PAC) spending. Our estimates imply that 6.3 percent of corporate charitable giving may be politically motivated, an amount 2.5 times larger than annual PAC contributions and 35 percent of federal lobbying. Absent of disclosure requirements, charitable giving may be a form of corporate political influence undetected by voters and subsidized by taxpayers. (JEL D22, D64, D72, L31)

Information is central to designing effective policy, and policy makers often rely on competing interests to separate useful from biased information. We show how this logic of virtuous competition can break down, using a new and comprehensive data set on U.S. federal regulatory rulemaking for 2003–2016. For-profit corporations and nonprofit entities are active in the rulemaking process and are arguably expected to provide independent viewpoints. Policy makers, however, may not be fully aware of the financial ties between some firms and nonprofits—grants that are legal and tax-exempt but hard to trace. We document three patterns that suggest that these grants may distort policy. First, we show that shortly after a firm donates to a nonprofit, the nonprofit is more likely to comment on rules on which the firm has also commented. Second, when a firm comments on a rule, the comments by nonprofits that recently received grants from the firm’s foundation are systematically closer in content to the firm’s own comments, relative to comments submitted by other nonprofits. Third, the final rule’s discussion by a regulator is more similar to the firm’s comments on that rule when the firm’s recent grantees also commented on it.