Per Östberg

Stock Investments at Work

Stock market investment decisions of individuals are positively correlated with that of co-workers. Sorting of unobservably similar individuals to the same workplaces is unlikely to explain our results, as evidenced by the investment behavior of individuals that move between plants. Purchases made under stronger co-worker purchase activity are not associated with higher returns. Moreover, social interaction appears to drive the purchase of within-industry stocks; an investment mistake. Overall, our results suggest a strong influence of co-workers on investment choices, but not an influence that improves the quality of investment decisions.

The Sovereign Debt Crisis: Rebalancing or Freezes?

Using high-frequency data we document that episodes of market turmoil in the European sovereign bond market are on average associated with large decreases in trading volume. The response of trading volume to market stress is conditional on transaction costs. Low transaction cost turmoil episodes are associated with volume increases (investors rebalance), while high transaction cost turmoil periods are associated with abnormally low volume (market freezes). We find suggestive evidence of market freezes in response to shocks to the risk bearing capacity of market makers while investor rebalancing is triggered by wealth shocks. Overall, our results show that the recent sovereign debt crisis was not associated with large-scale investor rebalancing.

Evidence of Excess Comovement in US Mergers

This paper considers changes in market comovement of merging US firms. Comparing the expected to the actual post merger comovement, we find that the post merger beta exhibits excess comovement with the acquiring firm. This suggests that the firm’s comovement is at least partly determined by its investors. We find that the excess comovement is significantly greater in cash transactions, when target shareholders tender their entire stake, than in pure stock transactions. Additionally, we document that the excess comovement is greater when the target is included in the S&P 500 as a result of the merger.

Money and liquidity in financial markets

We argue that there is a connection between the interbank market for liquidity and the broader financial markets, which has its basis in demand for liquidity by banks. Tightness in the interbank market for liquidity leads banks to engage in what we term “liquidity pull-back,” which involves selling financial assets either by banks directly or by levered investors. Empirical tests support this hypothesis. While our data covers part of the recent crisis period, our results are not driven by the crisis. Our general point is that money matters in financial markets. Different financial assets have different degrees of moneyness (liquidity) and, as a result, there are systematic cross-sectional variations in trading activity as the price of liquidity, or the level of tightness, in the interbank market fluctuates.