How do private equity firms affect their portfolio companies? We document operational changes in restaurant chain buyouts using comprehensive health inspection records. Storelevel operational practices improve after private equity buyout, as restaurants become cleaner, safer, and better maintained. Supporting a causal interpretation, this effect is stronger in chain-owned stores than in franchised locations—"twin" restaurants over which private equity owners have limited control. These changes are particularly apparent when private equity partners have prior industry experience. The results suggest that by bringing in industry expertise, private equity firms improve firm operations.

I compare the U.S. capacity expansion decisions of public and private producers of 7 commodity chemicals from 1989 to 2006. I find that private firms invest differently than public firms. Private firms are more likely than public firms to increase capacity prior to a positive demand shock (an increase in price and quantity) and less likely to increase capacity before a negative demand shock. Potential mechanisms include public firm overextrapolation of past demand shocks and agency problems arising from greater separation between ownership and control.

I document sources of value creation in mergers by analyzing novel data on the quality and price of goods sold by merging firms. When two competitors in a product market merge, their products converge in quality, and prices fall relative to the competition. These effects take two to three years to be fully realized and are stronger in mature industries. Prices do not fall, however, when the acquirer is diversifying into a new product market. This direct evidence of real changes induced by merger activity is consistent with consolidation by related merging firms to achieve operational efficiencies and lower costs.

How do private equity firms affect their portfolio companies? We document operational changes in restaurant chain buyouts using comprehensive health inspection records. Store-level operational practices improve after private equity buyout, as restaurants become cleaner, safer, and better maintained. Supporting a causal interpretation, this effect is stronger in chain-owned stores than in franchised locations—“twin” restaurants over which private equity owners have limited control. These changes are particularly apparent when private equity partners have prior industry experience. The results suggest that by bringing in industry expertise, private equity firms improve firm operations.

We investigate the effects of private equity firms on product markets using price and sales data for an extensive number of consumer products. Following a private equity deal, target firms increase retail sales of their products 50% more than matched control firms. Price increases—roughly 1% on existing products—do not drive this growth; the launch of new products and geographic expansion do. Competitors reduce their product offerings and marginally raise prices. Cross‐sectional results on target firms, private equity firms, the economic environment, and product categories suggest that private equity generates growth by easing financial constraints and providing managerial expertise.