美国经济评论（英文）.doc

American Economic Review美国经济评论Volume 100, Issue 4，20101. Title: Morally Motivated Self-Regulation.Authors: Baron, David P.Abstract: Self-regulation is the private provision of public goods and private redistribution. This paper examines the scope of self-regulation motivated by altruistic moral preferences that are reciprocal and stronger the closer are citizens in a socioeconomic distance. The focus is on the role of organizations in increasing self-regulation by mitigating free-rider problems. Social label and certification organizations can expand the scope of self-regulation but not beyond that with unconditional altruism. Enforcement organizations expand the scope of self-regulation farther, and for-profit enforcement is more aggressive than non-profit enforcement. Enforcement through social pressure imposed by NGOs also expands the scope of self-regulation.2. Title: Identifying the Elasticity of Substitution with Biased Technical Change.Authors: León-Ledesma, Miguel A; McAdam, Peter; Willman, Alpo.Abstract: The capital-labor substitution elasticity and technical biases in production are critical parameters. The received wisdom claims their joint identification is infeasible. We challenge that interpretation. Putting the new approach of 'normalized' production functions at the heart of a Monte Carlo analysis we identify the conditions under which identification is feasible and robust. The key result is that jointly modeling the production function and first-order conditions is superior to single-equation approaches especially when merged with 'normalization.' Our results will have fundamental implications for production-function estimation under non-neutral technical change, for understanding the empirical relevance of normalization and variability underlying past empirical studies.3. Title: Social Comparisons and Contributions to Online Communities: A Field Experiment on MovieLens.Authors: Chen, Yan; Harper, F. Maxwell; Konstan, Joseph; Li, Sherry Xin.Abstract: We design a field experiment to explore the use of social comparison to increase contributions to an online community. We find that, after receiving behavioral information about the median user's total number of movie ratings, users below the median demonstrate a 530 percent increase in the number of monthly movie ratings, while those above the median decrease their ratings by 62 percent. When given outcome information about the average user's net benefit score, above-average users mainly engage in activities that help others. Our findings suggest that effective personalized social information can increase the level of public goods provision.4. Title: Are Health Insurance Markets Competitive?Authors: Dafny, Leemore S.Abstract: To gauge the competitiveness of the group health insurance industry, I investigate whether health insurers charge higher premiums, ceteris paribus, to more profitable firms. Such 'direct price discrimination' is feasible only in imperfectly competitive settings. Using a proprietary national database of health plans offered by a sample of large, multisite firms from 1998-2005, I find firms with positive profit shocks subsequently face higher premium growth, even for the same health plans. Moreover, within a given firm, those sites located in concentrated insurance markets experience the greatest premium increases. The findings suggest health care insurers are exercising market power in an increasing number of geographic markets.5. Title: Wage Risk and Employment Risk over the Life Cycle.Authors: Low, Hamish; Meghir, Costas; Pistaferri, Luigi.Abstract: We specify a life-cycle model of consumption, labor supply and job mobility in an economy with search frictions. We distinguish different sources of risk, including shocks to productivity, job arrival, and job destruction. Allowing for job mobility has a large effect on the estimate of productivity risk. Increases in the latter impose a considerable welfare loss. Increases in employment risk have large effects on output and, primarily through this channel, affect welfare. The welfare value of programs such as Food Stamps, partially insuring productivity risk, is greater than the value of unemployment insurance which provides (partial) insurance against employment risk.6. Title: The Law of the Few.Authors: Galeotti, Andrea; Goyal, Sanjeev.Abstract: Empirical work shows that a large majority of individuals get most of their information from a very small subset of the group, viz., the influencers; moreover, there exist only minor differences between the observable characteristics of the influencers and the others. We refer to these empirical findings as the Law of the Few. This paper develops a model where players personally acquire information and form connections with others to access their information. Every (robust) equilibrium of this model exhibits the law of the few.7. Title: Technology Capital and the US Current A。