Perfect Information vs Random Investigation: Safety Guidelines for a Consumer in the Jungle of Product Differentiation

We present a graph-theoretic model of consumer choice, where final decisions are shown to be influenced by information and knowledge, in the form of individual awareness, discriminating ability, and perception of market structure. Building upon the distance-based Hotelling's differentiation idea, we describe the behavioral experience of several prototypes of consumers, who walk a hypothetical cognitive path in an attempt to maximize their satisfaction. Our simulations show that even consumers endowed with a small amount of information and knowledge may reach a very high level of utility. On the other hand, complete ignorance negatively affects the whole consumption process. In addition, rather unexpectedly, a random walk on the graph reveals to be a winning strategy, below a minimal threshold of information and knowledge.Comment: 27 pages, 12 figure

Sensitivity analysis of simulation experiments: Regression analysis and statistical design

Simulation;mathematische statistiek

The Origin, Development And Structure Of Demand For Plant Genetic Resources. The Impact Of The In Trust Agreements To The CGIAR Collections Availability

The objective of this paper is to explore how the demand of germplasm held by CGIAR genebanks changed over time in order to assess the possible influence of the 1994 In Trust Agreements on germplasm demand. The proposed theoretic model motivates the realistic hypothesis that the consequences of the In-Trust Agreements lead to an enhancement of CGIAR germplasm utilization. Therefore the paper firstly examines the classical literature on biodiversity’s valuation and its recent developments and subsequently it investigates the origin of the agricultural biodiversity’s economic value, providing a basic conceptual framework to infer on factors determining the demand for germplasm. Two Bayesian estimation frameworks are applied to the IRRI accessions distribution’s time-series to provide formal evidence to the hypothesis, exploiting Markov Chain Monte Carlo methods, Gibbs sampling in particular. Evidence suggests that the demand variation implies a change in the genetic collections economic value, impacting therefore on their direct use search value.Crop genetic resources, germplasm collection, search theoretic framework, count data, changepoints, O19, Q18, Q57, C11,

Covariate-assisted ranking and screening for large-scale two-sample inference

Two-sample multiple testing has a wide range of applications. The conventionalpractice first reduces the original observations to a vector of p-values and then chooses a cutoffto adjust for multiplicity. However, this data reduction step could cause significant loss ofinformation and thus lead to suboptimal testing procedures.We introduce a new framework fortwo-sample multiple testing by incorporating a carefully constructed auxiliary variable in inferenceto improve the power. A data-driven multiple-testing procedure is developed by employinga covariate-assisted ranking and screening (CARS) approach that optimally combines the informationfrom both the primary and the auxiliary variables. The proposed CARS procedureis shown to be asymptotically valid and optimal for false discovery rate control. The procedureis implemented in the R package CARS. Numerical results confirm the effectiveness of CARSin false discovery rate control and show that it achieves substantial power gain over existingmethods. CARS is also illustrated through an application to the analysis of a satellite imagingdata set for supernova detection

Group Size and Social Ties in Microfinance Institutions

Microfinance programmes provide poor people with small loans given to jointly liable self-selected groups. Follow-up loans provide incentives to repay. In an experiment we investigate the influence of those features on strategic default. Each group member invests in an individual risky project, whose outcome is known only to the individual investor. Subjects decide, whether to contribute to group repayment or not. Only those with successful projects can contribute. The experiment ends if too few repay. We investigate group size and social ties effects. We observe high repayments rates, which are robust across treatment. Group lending outperforms individual lending. Self-selected groups show a high but less stable willingness to contribute.microcredits, group lending, public goods, laboratory experiments, development economics