The U.S. business sector has under-invested relative to Tobin's Q since the early 2000's. We argue that declining competition is partly responsible for this phenomenon. We use a combination of natural experiments and instrumental variables to establish a causal relationship between competition...

We analyze private fixed investment in the U.S. over the past 30 years. We show that investment is weak relative to measures of profitability and valuation – particularly Tobin's Q, and that this weakness starts in the early 2000's. There are two broad categories of explanations: theories that...

We argue that earnings management and fraudulent accounting have important economic consequences. In a model where the costs of earnings management are endogenous, we show that in equilibrium, low-productivity firms hire and invest too much in order to pool with high productivity firms. This...