A brief survey of three lines of research I have been pursuing. for details, please see my web page.

1. On the Macroeconomic and Microeconomic Importance of Endogenous Technology Diego Comin BGIE

2. Plan Technology and economic development Technology and business cycles Technology and firm volatility

3. Technology Diffusion

4. Technology Diffusion

8. Technology and cycles

9. Medium Term Business Cycles Why are economic fluctuations so persistent? Shocks are persistent Persistent propagation mechanisms What propagation mechanisms induce persistence? Pro-cyclical development of new technologies (R&D) Pro-cyclical diffusion/adoption of new technologies

12. Implications for stock Market The persistence of fluctuations induces a small but very persistent component of firms’ profits. Large, persistent and pro-cyclical fluctuations in stock prices

14. Evolution of firm volatility

15. Robustness Also for other measures of performance: sales, employment, profits, sales per worker, return,… Not driven by possible change in the composition of publicly-traded companies Controls for age, size, firm foxed effects, cohort-specific effects of age and size Though privately held companies seem to have experienced declines in volatility since 1975

16. Why? Increased competition due to Prevalence of Schumpeterian dynamics: Decrease in adoption lags Increase in R&D activity Deregulation More access to capital because of development of financial markets

19. Deregulation

20. Consequences Increase in wage volatility Firms’ performance is more volatile They pass a larger part of risk to their workers