Sorting, Incentives and Risk Preferences: Evidence from a Field Experiment

The, often observed, positive correlation between incentive intensity and risk has been explained in two ways: the presence of transaction costs as determinants of contracts and the sorting of risk-tolerant individuals into firms using high-intensity incentive contracts. The empirical importance of sorting is perhaps best evaluated by directly measuring the risk tolerance of workers who have selected into incentive contracts under risky environments. We use experiments, conducted within a real firm, to measure the risk preferences of a sample of workers who are paid incentive contracts and face substantial daily income risk. Our experimental results indicate the presence of sorting; Workers in our sample are risk-tolerant. Moreover, their level of tolerance is considerably higher than levels observed for samples of individuals representing broader populations. Interestingly, the high level of risk tolerance suggests that both sorting and transaction costs are important determinants of contract choices when workers have heterogeneous preferences.Risk aversion, sorting, incentive contracts, field experiments

On the Relevance and Composition of Gifts within the Firm: Evidence from Field Experiments

We investigate the economic relevance and the composition of gifts within a firm where output is contractible. We develop a structural econometric model that identifies workers' optimal reaction to monetary gifts received from their employer. We estimate the model using data from two separate field experiments, both conducted within a tree-planting firm. We use the estimated structural parameters to generalize beyond the experiment, simulating how workers would react to different gifts on the part of the firm, within different labour-market settings. We find that gifts have a role to play within this firm, increasing in importance when the workers' outside alternatives deteriorate. Profit-maximizing gifts would increase profits within slack labour markets by up to 10% on average and by up to 17% for certain types of workers. These gifts represent significant increases in worker earnings; the average gift paid to workers attains 22% of average expected earnings in the absence of gifts. We find that gifts should be given by setting piece-rates above the market-clearing level rather than through fixed wages.gift giving, structural models, field experiments

Peer Pressure, Incentives, and Gender: an Experimental Analysis of Motivation in the Workplace

We present results from a real-effort experiment, simulating actual work-place conditions, comparing the productivity of workers under fixed wages and piece rates. Workers, who were paid to enter data, were exposed to different degrees of peer pressure under both payment systems. The peer pressure was generated in the form of private information about the productivity of their peers. We have two main results. First, we find no level of peer pressure for which the productivity of either male or female workers is significantly higher than productivity without peer pressure. Second, we find that very low and very high levels of peer pressure can significantly decrease productivity (particularly for men paid fixed wages). These results are consistent with models of conformism and self-motivation.Peer effects, fixed wages, piece rates, gender

Computational periscopy with an ordinary digital camera

Computing the amounts of light arriving from different directions enables a diffusely reflecting surface to play the part of a mirror in a periscope—that is, perform non-line-of-sight imaging around an obstruction. Because computational periscopy has so far depended on light-travel distances being proportional to the times of flight, it has mostly been performed with expensive, specialized ultrafast optical systems^1,2,3,4,5,6,7,8,9,10,11,12. Here we introduce a two-dimensional computational periscopy technique that requires only a single photograph captured with an ordinary digital camera. Our technique recovers the position of an opaque object and the scene behind (but not completely obscured by) the object, when both the object and scene are outside the line of sight of the camera, without requiring controlled or time-varying illumination. Such recovery is based on the visible penumbra of the opaque object having a linear dependence on the hidden scene that can be modelled through ray optics. Non-line-of-sight imaging using inexpensive, ubiquitous equipment may have considerable value in monitoring hazardous environments, navigation and detecting hidden adversaries.We thank F. Durand, W. T. Freeman, Y. Ma, J. Rapp, J. H. Shapiro, A. Torralba, F. N. C. Wong and G. W. Wornell for discussions. This work was supported by the Defense Advanced Research Projects Agency (DARPA) REVEAL Program contract number HR0011-16-C-0030. (HR0011-16-C-0030 - Defense Advanced Research Projects Agency (DARPA) REVEAL Program)Accepted manuscrip

Optimization Of Simulations And Activities For A New Introductory Quantum Mechanics Curriculum

The Institute of Physics New Quantum Curriculum (quantumphysics.iop.org) consists of online texts and interactive simulations with accompanying activities for an introductory course in quantum mechanics starting from two-level systems. Observation sessions and analysis of homework and survey responses from in-class trials were used to optimize the simulations and activities in terms of clarity, ease-of-use, promoting exploration, sense-making and linking of multiple representations. This work led to revisions of simulations and activities and general design principles which have been incorporated wherever applicable. This article describes the optimization of one of the simulation controls and the refinement of activities to help students make direct connections between multiple representations.Comment: 4 pages, 1 figure; submitted to the Proceedings of the 2013 Physics Education Research Conference. appears in 2013 PERC Proceedings [Portland, OR, July 17-18, 2013], edited by P. V. Engelhardt, A. D. Churukian, and D. L. Jone

Job-Hopping in Silicon Valley: Some Evidence Concerning the Micro-Foundations of a High Technology Cluster

Observers of Silicon Valley’s computer cluster report that employees move rapidly between competing firms, but evidence supporting this claim is scarce. Job-hopping is important in computer clusters because it facilitates the reallocation of talent and resources toward firms with superior innovations. Using new data on labor mobility, we find higher rates of job-hopping for college-educated men in Silicon Valley’s computer industry than in computer clusters located out of the state. Mobility rates in other California computer clusters are similar to Silicon Valley’s, suggesting some role for features of California law that make non-compete agreements unenforceable. Consistent with our model of innovation, mobility rates outside of computer industries are no higher in California than elsewhere.agglomerations, clusters, non-compete agreements, human capital, innovation, Silicon Valley, modular production.