Psychological and physiological adaptations to sperm competition in humans

Postcopulatory competition between males, in the form of sperm competition, is a widespread phenomenon in many animal species. The extent to which sperm competition has been an important selective pressure during human evolution remains controversial, however. The authors review critically the evidence that human males and females have psychological, behavioral, and physiological adaptations that evolved in response to selection pressures associated with sperm competition. The authors consider, using evidence from contemporary societies, whether sperm competition is likely to have been a significant adaptive problem for ancestral humans and examine the evidence suggesting that human males have physiological and psychological mechanisms that allow for “prudent” sperm allocation in response to variations in the risk of sperm competition

The Changing Role of Auditors in Corporate Tax Planning

This paper examines changes in the role that auditors play in corporate tax planning following recent events, including the well-known accounting scandals, passage of the Sarbanes-Oxley Act, and regulatory actions by the SEC and PCAOB. On the whole, these events have increased the sensitivity to and scrutiny of auditor independence. We examine the effects of these events on the market for tax planning, in particular the longstanding link between audit and tax services. While the effects are recent, they are already being seen in the data. Specifically, there has already been a dramatic shift in the market for tax planning away from obtaining tax planning services from one's auditor. We estimate that the ratio of tax fees to audit fees paid to the auditors of firms in the S&P 500 decline from approximately one in 2001 to one-fourth in 2004. At the same time, we find no evidence of a general decline in spending for tax services. In sum, the evidence indicates a decoupling of the longstanding link between audit and tax services, such that firms are shifting their purchase of tax services away from their auditor and towards other providers.

Capitalization of Capital Gains Taxes: Evidence from Stock Price Reactions to the 1997 Rate Reduction

We empirically document that stock prices moved inversely with dividend yields during the May, 1997 week, when the White House and Congress agreed on a budget accord that included a reduction in the capital gains tax rate. The share prices of firms not currently paying dividends increased approximately 6 percentage points more over a five-day window than the share prices of other firms. Among firms paying dividends, the change in share prices was decreasing in dividend yields. The results are consistent with at least two related explanations. First, to the extent a stock's returns are expected to be taxed as capital gains, a reduction in the expected capital gains tax rate enhances the attractiveness of the investment to investors. Second, to the extent a firm's stock is held by shareholders subject to the capital gains tax, a reduction in the expected capital gains tax rate increases its market value. The findings present evidence consistent with neither a sell-off of appreciated securities following the rate reduction nor a reduction in the compensation for capital gains taxes that selling shareholders demand from buyers. The upward price pressure around the accord dominated any downward price pressure imposed by these factors.

Conceptual design of an on-board optical processor with components

The specification of components for a spacecraft on-board optical processor was investigated. A space oriented application of optical data processing and the investigation of certain aspects of optical correlators were examined. The investigation confirmed that real-time optical processing has made significant advances over the past few years, but that there are still critical components which will require further development for use in an on-board optical processor. The devices evaluated were the coherent light valve, the readout optical modulator, the liquid crystal modulator, and the image forming light modulator

Complex permittivity measurements of lunar samples at microwave and millimeter wavelengths

The relative dielectric constant and loss tangent of lunar sample 14163,164 (fine dust) were determined as a function of density at 9.375, 24, 35, and 60 GHz. In addition, such measurements have also been performed on lunar sample 14310,74 (solid rock) at 9.375 GHz. The loss tangent was found to be frequency independent at these test frequencies and had a value of 0.015 for the lunar dust sample

Diversification and the Taxation of Capital Gains and Losses

Current U.S. law nets the total portfolio of realized capital gains and losses to compute capital gains taxes. Prior research, however, typically ignores the implication of this provision, i.e., the marginal tax rate for a specific gain or loss depends on the taxpayer's total portfolio of realized gains and losses. We find that these nettings introduce complexity into the relation between share values and capital gains taxes, creating an incentive to diversify. For firms with stock returns that are positively (negatively) correlated with those of the overall market, share values generally are decreasing (increasing) in the capital gains tax rate.