Editors’ note

Portuguese Economic Journal -     

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.     

上市公司内部审计知识管理如何影响内部审计外包

目前,许多上市公司为了提高自己的经营业绩进而增强自己的竞争实力,选择了将公司内部审计外包出去.但并不是所有的公司都具备将内部审计外包的条件.公司在决定是否将内部审计外包出去时,不得不考虑一些因素如内审资产的专用性、内审活动开展的频率、审计委员会的有效性等.本文分析研究了内部审计知识管理对内部审计外包的影响,经分析表明上市公司内部审计知识管理水平越高,内部审计外包的程度就会越低.