During the last three decades government debt has increased in most developed countries. During the same period we have also observed a significant liberalization of international financial markets. We propose a multicountry model with incomplete markets and show that governments may choose higher levels of debt when financial markets become internationally integrated. We also show that public debt increases with the volatility of uninsurable income (idiosyncratic risk). To the extent that the increase in income inequality observed in some industrialized countries has been associated with higher idiosyncratic risk, the paper suggests another potential mechanism for the rise in public debt.

We present a model of equity trading with informed and uninformed investors where informed investors trade on firm‐specific and marketwide private information. The model is used to identify the component of order flow due to marketwide private information. Estimated trades driven by marketwide private information display little or no correlation with the first principal component in order flow. Indeed, we find that co‐movement in order flow captures variation mostly in liquidity trades. Marketwide private information obtained from equity market data forecasts industry stock returns, and also currency returns.