Patterns of clustering in IPO gross spreads can be identified not only in the U.S., but also in many other markets across the world. The evidence indicates, however, that these clustering patterns are not necessarily collusive. Clustering is widespread in many countries with low gross spreads. In fact, the amount of clustering observed is negatively related to the gross spread level of a country. Additionally, an analysis of abnormal gross spreads following Hansen (2001) indicates that few clusters contain abnormal positive surpluses.

[Twenty countries around the world have used $27 billion in incentives such as bonus shares and discounts to attract retail investors to participate in privatizations and to discourage them from flipping their shares. Our results show that incentives have performed well, increasing retail investor participation much more cost effectively than underpricing. Flipping is not only much reduced in the short term but remains cumulatively at least 15% lower after 1000 trading days. The expiration of bonus share plans is associated with a 6-day abnormal return of -1.0% and a long-term increase in trading volume.]

We find that left-wing voters and politicians are less likely to invest in stocks, controlling for income, wealth, education, and other relevant factors. This finding from unique data sets in Finland is robust both at the zip code and at the individual level. A moderate left voter is 17–20% less likely to own stocks than a moderate right voter. The results are consistent with the idea that personal values are a factor in important investment decisions, in this case leading to “stock market aversion.” The results are inconsistent with alternative explanations such as wealth effects, risk aversion, reverse causality, return expectations, or social capital.

Twenty countries around the world have used $27 billion in incentives such as bonus shares and discounts to attract retail investors to participate in privatizations and to discourage them from flipping their shares. Our results show that incentives have performed well, increasing retail investor participation much more cost effectively than underpricing. Flipping is not only much reduced in the short term but remains cumulatively at least 15% lower after 1000 trading days. The expiration of bonus share plans is associated with a 6-day abnormal return of –1.0% and a long-term increase in trading volume.