Abstract This paper argues, both theoretically and empirically, that sometimes no securities law may be better than a good securities law that is not enforced. The first part of the paper formalizes the sufficient conditions under which this happens for any law. The second part of the paper shows that a specific securities law – the law prohibiting insider trading – may satisfy these conditions. The third part of the paper takes this prediction to the data. We find that the cost of equity actually rises when some countries enact an insider trading law, but do not enforce it.

ABSTRACT The existence and the enforcement of insider trading laws in stock markets is a phenomenon of the 1990s. A study of the 103 countries that have stock markets reveals that insider trading laws exist in 87 of them, but enforcement—as evidenced by prosecutions—has taken place in only 38 of them. Before 1990, the respective numbers were 34 and 9. We find that the cost of equity in a country, after controlling for a number of other variables, does not change after the introduction of insider trading laws, but decreases significantly after the first prosecution.

This paper examines the link between capital market governance (CMG) and several key measures of market performance. Using detailed data from individual stock exchanges, we develop a composite CMG index that captures three dimensions of security laws: the degree of earnings opacity, the enforcement of insider laws, and the effect of removing short-selling restrictions. We find that improvements in the CMG index are associated with decreases in the cost-of-equity capital (both implied and realized), increases in market liquidity (trading volume, market depth, and U.S. foreign investments), and increases in market pricing efficiency (reduced price synchronicity and IPO underpricing). The results are quite consistent across individual components of CMG and over alternative market performance measures.

We analyze financial statements from 34 countries for the period 1984–1998 to construct a panel data set measuring three dimensions of reported accounting earnings for each country: earnings aggressiveness, loss avoidance, and earnings smoothing. We hypothesize that these three dimensions are associated with uninformative or opaque earnings, and so we combine these three measures to obtain an overall earnings opacity time-series measure per country. We then explore whether our three measures of earnings opacity affect two characteristics of an equity market in a country: the return the shareholders demand and how much they trade. While not all results are consistent for our three individual earnings opacity measures, our panel data tests document that, after controlling for other influences, an increase in overall earnings opacity in a country is linked to an economically significant increase in the cost of equity and an economically significant decrease in trading in the stock market of that country.