Investment differences between public and private firms: Evidence from U.S. tax returns

Using tax data, we compare the investment behavior of public and private firms for a representative sample of all U.S. corporations. We find that while both types of firms invest similarly in physical capital, public firms out-invest private firms in R&D. Compared to observationally-similar private firms, public firms invest roughly 50% more in R&D relative to their asset bases. Further, public firms dedicate 7.4 percentage points more of their investments to R&D than private firms. This stronger public firm R&D investment is muted when shareholder earnings pressures are heightened, but not so much as to overcome the baseline investment advantage.