How costly is the poor governance of market intermediaries? Using unique trade level data from the stock market in Pakistan, we find that when brokers trade on their own behalf, they earn annual rates of return that are 50-90 percentage points higher than those earned by outside investors. Neither market timing nor liquidity provision by brokers can explain this profitability differential. Instead we find compelling evidence for a specific trade-based “pump and dump” price manipulation scheme: When prices are low, colluding brokers trade amongst themselves to artificially raise prices and attract positive-feedback traders. Once prices have risen, the former exit leaving the latter to suffer the ensuing price fall. Conservative estimates suggest these manipulation rents can account for almost a half of total broker earnings. These large rents may explain why market reforms are hard to implement and emerging equity markets often remain marginal with few outsiders investing and little capital raised.

Abstract We provide a model of bookbuilding in IPOs, in which the issuer can choose to ration shares. Before informed investors submit their bids, they know that, in the aggregate, winning bidders will receive only a fraction of their demand. We demonstrate that this mitigates the winner's curse, that is, the incentive of bidders to shade their bids. It leads to more aggressive bidding, to the extent that rationing can be revenue-enhancing. In a parametric example, we characterize bid and revenue functions, and the optimal degree of rationing. We show that, when investors’information is diffuse, maximal rationing is optimal. Conversely, when their information is concentrated, the seller should not ration shares. We provide testable predictions on bid dispersion and the degree of rationing. Our model reconciles the documented anomaly that higher bidders in IPOs do not necessarily receive higher allocations.

Abstract Popular investment advice recommends that stock/bond and stock/wealth ratios should rise with investor risk tolerance and investment horizon respectively, prescriptions that are difficult to reconcile with the simple mean-variance model. We show that extending the mean-variance model to include human capital, without any other modifications, can simultaneously justify both recommendations, so long as the correlation between labour income and stock returns falls within a range determined by market and investor-specific parameters. Aggregate labour income data from 11 countries generally satisfy this requirement, as do plausible individual income processes. We also consider the implications of human capital for the optimal bond/wealth ratio over the investment horizon, and examine the sensitivity of the stock/bond mix to the volatility of labour income.

Abstract Individuals who have their tax returns professionally prepared often overpay estimated income taxes, effectively giving the government an interest‐free loan. To understand why tax professionals may place their clients in positive prepayment positions, we draw on mental accounting theory. Mental accounting theory suggests that by placing taxpayers in positive prepayment positions, tax professionals induce a favorable mental representation of tax return preparation fees, perhaps allowing them to collect larger fractions of billable time and costs incurred on taxpayers' behalves. Thus, we hypothesize that tax return preparation fees are higher for taxpayers in positive prepayment positions than for taxpayers in negative prepayment positions. Regression results using tax return data for 68,736 taxpayers provide strong support for this hypothesis. To more fully understand the general nature of the relationship between taxpayers' prepayment positions and tax return preparation fees, we adapt the prospect theory value function to the tax domain and formulate three additional hypotheses. Consistent with theory, regression results indicate that the relation between taxpayers' prepayment positions and tax return preparation fees is (1) positive, (2) stronger for taxpayers who receive refunds that are less than fees than it is for taxpayers who receive refunds that are greater than fees, and (3) stronger for taxpayers in negative prepayment positions than for taxpayers in positive prepayment positions.

During the decade of the 1990s the number of women serving on corporate boards increased substantially. Over this decade, we show that the likelihood of a firm adding a woman to its board in a given year is negatively affected by the number of woman already on the board. The probability of adding a woman is materially increased when a female director departs the board. Adding a director, therefore, is clearly not gender neutral. Although we find that women tend to serve on better performing firms, we also document insignificant abnormal returns on the announcement of a woman added to the board. Rather than the demand for women directors being performance based, our results suggest corporations responding to either internal or external calls for diversity.

This paper simulates the impact of the AIDS epidemic on future living standards in South Africa. I emphasize two competing effects. On the one hand, the epidemic is likely to have a detrimental impact on the human capital accumulation of orphaned children. On the other hand, widespread community infection lowers fertility, both directly, through a reduction in the willingness to engage in unprotected sexual activity, and indirectly, by increasing the scarcity of labor and the value of a woman's time. I find that even with the most pessimistic assumptions concerning reductions in educational attainment, the fertility effect dominates. The AIDS epidemic, on net, enhances the future per capita consumption possibilities of the South African economy.