The cost of financial intermediation has declined in recent years thanks to technological progress and increased competition. I document this fact and I analyze two features of new financial technologies that have stirred controversy: returns to scale, and the use of big data and machine...

I analyze efficient government interventions to mitigate financial distress during a severe macroeconomic downturn. At the macroeconomic level, the key variable is the gap between the real wage and the shadow cost of labor. This gap is large when unemployment is high. At the micro level,...

I propose an implementation of the q-theory of investment using bond prices instead of equity prices. Credit risk makes corporate bond prices sensitive to future asset values, and q can be inferred from bond prices. The bond market's q performs much better than the usual measure in standard...

Growth theory is based on the assumption of exponential total factor productivity (TFP) growth. Across countries and time periods I find that TFP growth is actually linear. Unlike the exponential model, the additive growth model provides useful medium-term forecasts of TFP. It also explains the...

We provide an empirical and theoretical analysis of the Greek Crisis of 2010. We first benchmark the crisis against all episodes of sudden stops, sovereign debt crises, and lending boom/busts in emerging and advanced economies since 1980. The decline in Greece's output, especially investment, is...

We study a model where firms accumulate data as a valuable intangible asset. Data accumulation affects firms' dynamics. It increases the skewness of the firm size distribution as large firms generate more data and invest more in active experimentation. On the other hand, small data- savvy firms...

We study the evolution of super star firms in the U.S. economy over the past 60 years. Contrary to common wisdom, super stars firms have not become larger, have not become more productive, and the contribution of star firms to aggregate U.S. productivity growth has fallen by more than one third...

We propose a model to identify the causes of rising profits and concentration, and declining entry and investment in the US economy. Our approach combines a rich structural DSGE model with cross-sectional identification from firm and industry data. Using asset prices, our model estimates the...

We study the evolution of profits, investment and market shares in US industries over the past 40 years. During the 1990's, and at low levels of initial concentration, we find evidence of efficient concentration driven by tougher price competition, intangible investment, and increasing...