This paper empirically analyzes pollution abatement regulation within the context of the Clean Air Act's nonattainment status designation and shows that financial constraints are an important determinant of whether spending on mandatory pollution abatement crowds out or stimulates R&D investment and capital expenditure. We show that spending on mandatory pollution abatement and other investments are complements for financially unconstrained firms but substitutes for constrained firms. Financially unconstrained firms invest more and have lower current profits but higher future profits; financially constrained firms invest less and have stable current profits but lower long-term profits.

We find that the effect of political connections on tax planning depends on firms’ financial conditions. After increased political connections, financially unconstrained firms increase tax planning and spending on tax services, as documented in prior studies, whereas constrained firms decrease tax planning and spending on tax services. Moreover, decreases in tax planning are only present for constrained firms that obtain new bank loans and public debt and when the connected politicians serve on banking-related committees. Our results suggest that by facilitating access to external financing, political connections reduce financially constrained firms’ use of tax planning as an internal financing tool.