Minority vs. Majority: An Experimental Study of Standardized Bids

Due to its simplicity the plurality voting system is frequently used to choose a common representative or project. Nevertheless it may fail to provide a socially efficient decision as a majority can outvote any minority even if the majority's gain does not compensate the loss suffered by the minority. In this paper we propose and study a simple mechanism that allows voters to reveal more information about their preferences over the candidates. According to the standardized bids mechanism voters report a bid for all the available projects. Standardization ensures the existence of equilibrium, and delivers incentives to overcome the problem of positive and negative exaggeration. Our experimental results show that the standardized bids mechanism performed well in the laboratory as it chose the efficient project in almost three quarters of the cases, and induced truthful reports of project rankings in approximately 90% of the cases. For a reference, we also present experimental results for the plurality voting scheme.

College Admissions and the Role of Information: An Experimental Study

We analyze two well-known matching mechanisms\the Gale-Shapley, and the Top Trading Cycles (TTC) mechanisms\in theexperimental lab in three different informational settings, and study the role of information in individual decision making. Our results suggest that\in line with the theory\in the college admissions model the Gale-Shapley mechanism outperforms the TTC mechanisms in terms of efficiency and stability, and it is as successful as the TTC mechanism regarding the proportion of truthful preference revelation. In addition, we find that information has an important effect on truthful behavior and stability. Nevertheless, regarding efficiency, the Gale-Shapley mechanism is less sensitive to the amount of information participants hold.

College admissions and the role of information : an experimental study

We analyze two well-known matching mechanisms—the Gale-Shapley, and the Top Trading Cycles (TTC) mechanisms—in the experimental lab in three different informational settings, and study the role of information in individual decision making. Our results suggest that—in line with the theory—in the college admissions model the Gale-Shapley mechanism outperforms the TTC mechanisms in terms of efficiency and stability, and it is as successful as the TTC mechanism regarding the proportion of truthful preference revelation. In addition, we find that information has an important effect on truthful behavior and stability. Nevertheless, regarding efficiency, the Gale-Shapley mechanism is less sensitive to the amount of information participants hold.Experiments, Information, Matching

MathOptimizer: a nonlinear optimization package for mathematica users

Özyeğin University Technical ReportMathematica is an advanced software system that enables symbolic computing, numerics, program code development, model visualization and professional documentation in a unified framework. Our MathOptimizer software package serves to solve global and local optimization models developed using Mathematica. We introduce MathOptimizer’s key features and discuss its usage options that support a range of operational modes. The numerical capabilities of the package are illustrated by simple and more advanced examples, pointing towards a broad range of potential applications

Decentralized matching markets : a laboratory experiment

We report data from controlled laboratory experiments on two-sided matching markets in which participants interact in a decentralized way, without having to refer to a central clearinghouse. Our treatments have been designed to evaluate the effect of information, search costs, and binding agreements on the final outcome and also on the individual strategies that lead to it. We find that these features affect the level and pace of market activity as well as the identity of those who receive proposals. While the lack of information alone does not reduce stability or efficiency, its combination with search costs can be detrimental.Financial support from Fundação para a Ciência e Tecnologia (FCCN); Juan de la Cierva program of the Spanish Ministry of Science and Innovation

Photosynthesis and conductance of spring-wheat leaves: field response to continuous free-air atmospheric CO2 enrichment

Spring wheat was grown from emergence to grain maturity in two partial pressures of CO2 (pCO2): ambient air of nominally 37 Pa and air enriched with CO2 to 55 Pa using a free-air CO2 enrichment (FACE) apparatus. This experiment was the first of its kind to be conducted within a cereal field without the modifications or disturbance of microclimate and rooting environment that accompanied previous studies. It provided a unique opportunity to examine the hypothesis that continuous exposure of wheat to elevated pCO2 will lead to acclimatory loss of photosynthetic capacity. The diurnal courses of photosynthesis and conductance for upper canopy leaves were followed throughout the development of the crop and compared to model-predicted rates of photosynthesis. The seasonal average of midday photosynthesis rates was 28% greater in plants exposed to elevated pCO2 than in contols and the seasonal average of the daily integrals of photosynthesis was 21% greater in elevated pCO2 than in ambient air. The mean conductance at midday was reduced by 36%. The observed enhancement of photosynthesis in elevated pCO2 agreed closely with that predicted from a mechanistic biochemical model that assumed no acclimation of photosynthetic capacity. Measured values fell below predicted only in the flag leaves in the mid afternoon before the onset of grain-filling and over the whole diurnal course at the end of grain-filling. The loss of enhancement at this final stage was attributed to the earlier senescence of flag leaves in elevated pCO2. In contrast to some controlled-environment and field-enclosure studies, this field-scale study of wheat using free-air CO2 enrichment found little evidence of acclimatory loss of photosynthetic capacity with growth in elevated pCO2 and a significant and substantial increase in leaf photosynthesis throughout the life of the crop