Despite their importance, the discussion of spillover effects in empirical research often misses the rigor dedicated to endogeneity concerns. We analyze a broad set of workhorse models of firm interactions and show that spillovers naturally arise in many corporate finance settings. This has important implications for the estimation of treatment effects: i) even with random treatment, spillovers lead to a complicated bias, ii) fixed effects can exacerbate the spillover-induced bias. We propose simple diagnostic tools for empirical researchers and illustrate our guidance in an application.

I analyze the impact of the formation of universal banks on corporate investment by looking at the gradual dismantling of the Glass-Steagall Act’s separation between commercial and investment banking. Using a sample of US firms and their relationship banks, I show that firms curtail debt issuance and investment after positive shocks to the underwriting capacity of their main bank. This result is driven by unrated firms and is strongest immediately after a shock. These findings suggest that universal banks may pay more attention to large firms providing more underwriting opportunities while exacerbating financial constraints of opaque firms, in line with a shift to a banking model based on transactional lending.

This paper documents a link between bank concentration and markups in nonfinancial sectors. We exploit concentration-increasing bank mergers and variation in banks’ market shares across industries and show that higher credit concentration is associated with higher markups and that high-market-share lenders charge lower loan rates. We argue that this is due to the greater incidence of competing firms sharing common lenders that induce less aggressive product market behavior among their borrowers, thereby internalizing potential adverse effects of higher rates. Consistent with our conjecture, the effect is stronger in industries with competition in strategic substitutes where negative product market externalities are greatest.

A natural experiment and matched bank/firm data are used to identify the effects of bank guarantees on allocative efficiency. We find that with guarantees in place unproductive firms receive larger loans, invest more, and maintain higher rates of sales and wage growth. Moreover, firms produce less productively. Firms also survive longer in banks’ portfolios and those that enter guaranteed banks’ portfolios are less profitable and productive. Finally, we observe fewer economy-wide firm exits and bankruptcy filings in the presence of guarantees. Overall, the results are consistent with the idea that guaranteed banks keep unproductive firms in business for too long.

I model the joint effects of debt, macroeconomic conditions, and cash flow cyclicality on risk-shifting behavior and managerial wealth-for-performance sensitivity. The model shows that risk-shifting incentives rise during recessions and that the shareholders can eliminate such adverse incentives by reducing the equity-based compensation in managerial contracts. Moreover, this reduction should be larger in highly procyclical firms. These novel, testable predictions provide insights into optimal shareholder responses to agency costs of debt throughout the business cycle.

We exploit the spatial and temporal variation of the staggered introduction of interstate banking deregulation across the U.S. to study the relationship between credit constraints and consumption of durables. Using the American Housing Survey from 1981 to 1993, we link the timing of these reforms with evidence of a credit expansion and household responses on many margins. We find robust evidence that households are more likely to purchase new appliances and invest in home renovations and modifications after the deregulation. These durable goods allowed households to consume less electricity and spend less time in domestic activities after the reforms.