The online laboratory: conducting experiments in a real labor market

Online labor markets have great potential as platforms for conducting experiments. They provide immediate access to a large and diverse subject pool, and allow researchers to control the experimental context. Online experiments, we show, can be just as valid—both internally and externally—as laboratory and field experiments, while often requiring far less money and time to design and conduct. To demonstrate their value, we use an online labor market to replicate three classic experiments. The first finds quantitative agreement between levels of cooperation in a prisoner’s dilemma played online and in the physical laboratory. The second shows—consistent with behavior in the traditional laboratory—that online subjects respond to priming by altering their choices. The third demonstrates that when an identical decision is framed differently, individuals reverse their choice, thus replicating a famed Tversky-Kahneman result. Then we conduct a field experiment showing that workers have upward-sloping labor supply curves. Finally, we analyze the challenges to online experiments, proposing methods to cope with the unique threats to validity in an online setting, and examining the conceptual issues surrounding the external validity of online results. We conclude by presenting our views on the potential role that online experiments can play within the social sciences, and then recommend software development priorities and best practices.     

Flows of people,flows of ideas,and the inequality of nations

The present paper examines a neglected determinant of aggregate productivity: temporary cross-border flows of people. We hypothesize that interaction between people from different nations facilitates the international diffusion of ideas, thus stimulating aggregate productivity. In order to assess the causal impact of people flows on productivity, we construct an instrument for people flows. By analogy to the trade/growth literature, this instrument is derived from a fitted gravity equation involving geographic determinants of bilateral travel flows. Our cross-section analysis reveal that greater international interaction leads to higher productivity; a very similar result, qualitatively as well as quantitatively, is obtained when we employ dynamic panel data methods for the purpose of identification.     

The role of role uncertainty in modified dictator games

We compare behavior in modified dictator games with and without role uncertainty. Subjects choose between a selfish action, a costly surplus creating action (altruistic behavior) and a costly surplus destroying action (spiteful behavior). While costly surplus creating actions are the most frequent under role uncertainty (64%), selfish actions become the most frequent without role uncertainty (69%). Also, the frequency of surplus destroying choices is negligible with role uncertainty (1%) but not so without it (11%). A classification of subjects into four different types of interdependent preferences (Selfish, Social Welfare maximizing, Inequity Averse and Competitive) shows that the use of role uncertainty overestimates the prevalence of Social Welfare maximizing preferences in the subject population (from 74% with role uncertainty to 21% without it) and underestimates Selfish and Inequity Averse preferences. An additional treatment, in which subjects undertake an understanding test before participating in the experiment with role uncertainty, shows that the vast majority of subjects (93%) correctly understand the payoff mechanism with role uncertainty, but yet surplus creating actions were most frequent. Our results warn against the use of role uncertainty in experiments that aim to measure the prevalence of interdependent preferences.     

Innovations,patent races and endogenous growth

This paper presents a model of innovations and endogenous economic growth with two main assumptions: first, the cost of searching for innovations differs across innovations, and second, innovations take time to find. The paper shows that given these two assumptions together, competition leads to patent races and to duplication of innovative activity. The paper then shows that duplication significantly reduces the effect of scale on growth. It also shows that competitive R&D creates too much research on easy innovations, and too little research on the difficult ones. Finally, the paper shows that risk sharing might increase duplication and reduce growth.     

Sustaining cooperation in laboratory public goods experiments: a selective survey of the literature

I survey the literature post Ledyard (Handbook of Experimental Economics, ed. by J. Kagel, A. Roth, Chap. 2, Princeton, Princeton University Press, 1995) on three related issues in linear public goods experiments: (1) conditional cooperation; (2) the role of costly monetary punishments in sustaining cooperation and (3) the sustenance of cooperation via means other than such punishments. Many participants in laboratory public goods experiments are “conditional cooperators” whose contributions to the public good are positively correlated with their beliefs about the average group contribution. Conditional cooperators are often able to sustain high contributions to the public good through costly monetary punishment of free-riders but also by other mechanisms such as expressions of disapproval, advice giving and assortative matching.     

Consumer specialization and the Romantic transformation of the British Grand Tour of Europe

This paper posits that significant changes in 19th century British recreational travel patterns resulted from a change in the manner in which tourists used entertaining stimuli in order to attain pleasure. Consumers no longer merely viewed arousing stimuli, but attempted to use them to produce emotional states of being which they could partially modify to intensify pleasurable feelings (Damasio, Looking for Spinoza: Joy, sorrow, and the feeling brain, William Heinemann, 2003). The impetus for this modification stemmed from an increasing awareness that emotional responses could be to some degree self-cultivated, as embodied in the Romantic ethos that become popular at the time via the emergence of the paperback novel and magazine industry (Campbell, The romantic ethic and the spirit of modern consumerism, Blackwell, 1987). By learning how to manipulate and modify mental images in a way that may not necessarily correspond with objective reality, Romantic tourists learned to elicit pleasure through engaging of their imagination. Such a change in the mode of pleasure seeking had important long run economic consequences for tourist regions throughout the European continent.     

基于PHP的电子文献资料管理系统

电子文献资料管理是提高企业信息化管理水平、提高管理效率,进而抓住机遇、增强自身实力及竞争力的重要保障。在总结了烟草行业多年的信息管理有效经验的基础上,采用B/S结构,利用PHP技术,实现了对电子文献资料的信息管理与信息挖掘。系统运行表明:该系统能够很好地满足企业对文献资料的存储、查询、分析和共享等需要,使文献资料及时、有效、准确地传递及处理。此系统的建立,大大提高了企业内部文献资料的管理水平。     

国际金融危机与我国先发地区产业转移——以外向型"东莞模式"为例

东莞市作为珠三角的经济先发地区,外向的劳动密集型产业基础强大。随着广东省产业转移战略的铺开,东莞产业发展的资源瓶颈效应和落后产业转移需求也很大,实施产业转移战略迫在眉睫。但是2007年的国际金融危机对东莞经济系统及产业转移战略造成了一定的外部冲击。在这种经济环境和固有的制度背景下,产业转移战略在经济先发地区应该如何推进?本文将以劳动密集型产业集聚的东莞市为例,分析经济先发地区推动产业转移的成效与不足,从而为产业转移这种产业政策的学术研究提供理论依据与实践素材。