We measure the distribution of welfare losses from non-competitive behaviour in the U.S. credit card industry during the 1970s and 1980s. The early credit card industry was characterized by regional monopolies. Ensuing legal decisions led to competitive reforms that resulted in greater, but still limited, oligopolistic competition. We measure the distributional consequences of these reforms by developing and estimating a heterogeneous agent, defaultable debt framework with oligopolistic lenders. The transition from monopoly to oligopolistic competition yields welfare gains equivalent to a one-time transfer worth $3,600 (in 2016 dollars) for the bottom decile of earners (roughly 50% of their annual income) versus $1,200 for the top decile of earners. As the credit market expands, low-income households benefit more since they rely disproportionately on credit to smooth consumption. Greater competition also explains rising bankruptcies, chargeoffs, and credit to income ratios. Lastly, we bound the welfare gains from competition by computing a perfectly competitive benchmark. Aggregate welfare gains are 40% larger from perfect competition but distributed similarly to oligopolistic competition.

Many argue that minimum wages can prevent efficiency losses from monopsony power. We assess this argument in a general equilibrium model of oligopsonistic labor markets with heterogeneous workers and firms. We decompose welfare gains into an efficiency component that captures reductions in monopsony power and a redistributive component that captures the way minimum wages shift resources across people. The minimum wage that maximizes the efficiency component of welfare lies below $8.00 and yields gains worth less than 0.2% of lifetime consumption. When we add back in Utilitarian redistributive motives, the optimal minimum wage is $11 and redistribution accounts for 102.5% of the resulting welfare gains, implying offsetting efficiency losses of −2.5%. The reason a minimum wage struggles to deliver efficiency gains is that with realistic firm productivity dispersion, a minimum wage that eliminates monopsony power at one firm causes severe rationing at another. These results hold under an EITC and progressive labor income taxes calibrated to the U.S. economy.

For whom has earnings risk changed, and why? We answer these questions by combining the Kalman filter and EM algorithm to estimate persistent and temporary earnings for every individual at every point in time. We apply our method to administrative earnings linked with survey data. We show that since the 1980s, persistent earnings risk rose by 12.5 percent for both employed and unemployed workers and the scarring effects of unemployment doubled. At the same time, temporary earnings risk declined. Using education and occupation codes, we show that rising persistent earnings risk is concentrated among high-skill workers and related to technology adoption.