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71.
A bstract .   This paper is an analysis of the demand for thoroughbred racetrack wagers, examining evidence that would support the existence of two types of bettors: the risk-averse informed bettor versus the uninformed bettor. Looking at 12 major racetracks over the fall of 2002, we undertake an empirical examination of the determinants of bettors' preferences for particular wagers on specific races. The goal is to try to determine what individual aspects of a race (conditions, surface, participants, etc.) will encourage increased wagering dollars. With the advent of simulcasting, the competition for the wagering dollar is fierce, as the bettor can choose from more than 100 races daily, each race offering numerous betting options. We find for most wagers that higher quality participants, larger and more competitive fields, and turf races increase betting volume while higher pari-mutuel takeout, poor track conditions, and other races run concurrently reduce volume. However, more competitive fields reduce betting volume in the show and trifecta pools. Optimal field size is determined to be between 10 and 12 betting interests. Overall, we find support for the existence of a significant share of risk-averse informed bettors.  相似文献   
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Several evolutionary mechanisms have been identified in the literature that would generate altruism in humans. The most powerful (except for kin selection) and most controversial is group selection, as recently analyzed by Sober & D.S. Wilson. I do not take a stand on the issue of the existence of group selection. Instead, I examine the level of human altruism that could exist if group selection were an engine of human evolution. For the Sober & Wilson mechanism to work, groups practicing altruism must grow faster than other groups. I call altruistic behavior that would lead to faster growth efficient altruism. This often consists of cooperation in a prisoner's dilemma. ltruistic acts such as helping a temporarily hungry or injured person would qualify as efficient altruism. Efficient altruism would also require monitoring recipients to avoid shirking. Utilitarianism would be an ethical system consistent with efficient altruism, but Marxism or the Rawlsian system would not. Discussions of efficient altruism also help understand intuitions about fairness. We perceive those behaviors as fair that are consistent with efficient altruism. It is important to understand that, even if humans are selected to be altruistic, the forms of altruism that might exist must be carefully considered and ircumscribed.  相似文献   
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A maximum likelihood method to estimate the parameters of dynamic models containing unobserved independent variables is proposed. The approach is to maximize the likelihood of the residuals produced by the recursive Kalman filter equations applied to the model in state-space form. A simulation study is presented comparing the proposed method to the instrumental variable approach. An example using real data is given which estimates models of the Permanent-Income Hypothesis.  相似文献   
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Overfishing and excess capacity in mostfisheries around the world have generated considerableand increasing concern about their biological and economic performance ramifications. Theseproblems, in part, stem from substantialinvestment in technical improvements to boats andequipment in fishing fleets, which exacerbatesexcess fishing capacity and low returns tofishing effort and investment, given regulatoryand biological constraints. However, little attempt hasbeen made to quantify the extent or effects oftechnical change in fisheries. In this paper, we usedetailed data on innovation patterns for 19vessels in the Sète trawl fleet of southernFrance to evaluate the contributions oftechnical change to catch rates. We find thatembodied technical change enhanced productivity by approximately one percent per year between 1985 and 1999, but that external (disembodied) events counteractedthis trend, causing a net output decline ofabout three percent per year.  相似文献   
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