Tetsuo Yamamori

Bio: Tetsuo Yamamori is an academic researcher from University of Tokyo. The author has contributed to research in topics: Solution concept & Epsilon-equilibrium. The author has an hindex of 3, co-authored 5 publications receiving 109 citations.

Voice matters in a dictator game

Abstract: We conducted a laboratory experiment to study the effects of communication in a dictator game, while maintaining subjects’ anonymity. In the experiment, the recipient has an opportunity to state a payoff-irrelevant request for his/her share before the dictator dictates his/her offer. We found that the independence hypothesis that voice does not matter is rejected. In particular, if the request is for less than half of the pie, the dictator’s offer increases as the recipient’s request increases. Additionally, there is no dictator who is other-regarding and, at the same time, does not react to the recipient’s request.

Improvement dynamics in games with strategic complementarities

Abstract: In a finite game with strategic complementarities, every strategy profile is connected to a Nash equilibrium with a finite individual improvement path. If, additionally, the strategies are scalar, then every strategy profile is connected to a Nash equilibrium with a finite individual best response improvement path.

The pure Nash equilibrium property and the quasi-acyclic condition

Abstract: This paper presents a sufficient condition for the quasi-acyclic condition. A game is quasi-acyclic if from any strategy profile, there exists a finite sequence of strict best replies that ends in a pure strategy Nash equilibrium. The best-reply dynamics must converge to a pure strategy Nash equilibrium in any quasi-acyclic game. A game has the pure Nash equilibrium property (PNEP) if there is a pure strategy Nash equilibrium in any game constructed by restricting the set of strategies to a subset of the set of strategies in the original game. Any finite, ordinal potential game and any finite, supermodular game have the PNEP. We show that any finite, two-player game with the PNEP is quasi-acyclic.

When you ask zeus a favor: the third party's voice in a dictator game

Abstract: We conducted a laboratory experiment on a dictator game with the option for a “voice” by a third party and compared it with the dictator game with a “voice” by the recipient. Our findings are as follows. The dictators' offers in response to an aggressive voice of the recipients are significantly lower than the dictators' offers in response to the corresponding voice of the third party. The dictators' responses to an aggressive voice differentiate the effects of the recipient's voice from those of the third party's.

Dictator games: a meta study

Abstract: Over the last 25 years, more than a hundred dictator game experiments have been published. This meta study summarises the evidence. Exploiting the fact that most experiments had to fix parameters they did not intend to test, in multiple regression the meta study is able to assess the effect of single manipulations, controlling for a host of alternative explanatory factors. The resulting rich dataset also provides a testbed for comparing alternative specifications of the statistical model for analysing dictator game data. It shows how Tobit models (assuming that dictators would even want to take money) and hurdle models (assuming that the decision to give a positive amount is separate from the choice of amount, conditional on giving) provide additional insights.

Analysis of Genetic Diversity in Crop Plants—Salient Statistical Tools and Considerations

Abstract: Knowledge about germplasm diversity and genetic relationships among breeding materials could be an invaluable aid in crop improvement strategies. A number of methods are currently available for analysis of genetic diversity in germplasm accessions, breeding lines, and populations. These methods have relied on pedigree data, morphological data, agronomic performance data, biochemical data, and more recently molecular (DNA-based) data. For reasonably accurate and unbiased estimates of genetic diversity, adequate attention has to be devoted to (i) sampling strategies; (ii) utilization of various data sets on the basis of the understanding of their strengths and constraints; (iii) choice of genetic distance measure(s), clustering procedures, and other multivariate methods in analyses of data; and (iv) objective determination of genetic relationships. Judicious combination and utilization of statistical tools and techniques, such as bootstrapping, is vital for addressing complex issues related to data analysis and interpretation of results from different types of data sets, particularly through clustering procedures. This review focuses on application of statistical tools and techniques in analysis of genetic diversity at the intraspecific level in crop plants.

Algorithms for hierarchical clustering: an overview

Abstract: We survey agglomerative hierarchical clustering algorithms and discuss efficient implementations that are available in R and other software environments. We look at hierarchical self-organizing maps and mixture models. We review grid-based clustering, focusing on hierarchical density-based approaches. Finally, we describe a recently developed very efficient (linear time) hierarchical clustering algorithm, which can also be viewed as a hierarchical grid-based algorithm. This review adds to the earlier version, Murtagh F, Contreras P. Algorithms for hierarchical clustering: an overview, Wiley Interdiscip Rev: Data Mining Knowl Discov 2012, 2, 86–97. WIREs Data Mining Knowl Discov 2017, 7:e1219. doi: 10.1002/widm.1219 This article is categorized under: Algorithmic Development > Hierarchies and Trees Technologies > Classification Technologies > Structure Discovery and Clustering

Global monitoring of large reservoir storage from satellite remote sensing

Abstract: [1] We studied 34 global reservoirs for which good quality surface elevation data could be obtained from a combination of five satellite altimeters for the period from 1992 to 2010. For each of these reservoirs, we used an unsupervised classification approach using the Moderate Resolution Imaging Spectroradiometer (MODIS) 16-day 250 m vegetation product to estimate the surface water areas over the MODIS period of record (2000 to 2010). We then derived elevation-area relationships for each of the reservoirs by combining the MODIS-based estimates with satellite altimeter-based estimates of reservoir water elevations. Through a combination of direct observations of elevation and surface area along with documented reservoir configurations at capacity, we estimated storage time histories for each reservoir from 1992 to 2010. We evaluated these satellite-based data products in comparison with gauge observations for the five largest reservoirs in the United States (Lakes Mead, Powell, Sakakawea, Oahe, and Fort Peck Reservoir). The storage estimates were highly correlated with observations (R = 0.92 to 0.99), with values for the normalized root mean square error (NRMSE) ranging from 3% to 15%. The storage mean absolute error (expressed as a percentage of reservoir capacity) for the reservoirs in this study was 4%. The multidecadal reconstructed reservoir storage variations are in accordance with known droughts and high flow periods on each of the five continents represented in the data set.

Identification and Characterization of a Low Phytic Acid Wheat

Abstract: Phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, or Ins P 6 ) is the most abundant storage form of P in seeds, yet indigestible by humans and nonruminant livestock. A wheat (Triticum aestivum L.) mutant is described herein with greatly reduced seed phytic add P but little change in seed total P, similar to Ipal-type mutants described in other grain species. One nonlethal mutant from 562 ethyl-methanesulfonate (EMS) mutageniied M 2 lines was identified with a high inorganic phosphate (HIP) phenotype and designated Js-12-LPA. Js-12-LPA homozygotes produced seed in which phytic acid P represented 48.2% of seed total P, in contrast to 74.7% of seed total P in nonmutant or wild-type control, Js-12-WT. The inorganic portion of seed P was increased from 9.1% in Js-12-WT to 50.1% in Js-12-LPA, with little effect on total seed P. Weight distributions among milling fractions were similar for the Js-12-LPA and Js-12-WT genotypes. The low phytic acid trait altered the distribution of total P within the kernel, increasing the P content of the central endosperm and decreasing the P content of the bran. The low phytic acid trait decreased the phytic acid concentration in the bran by 43% and increased the inorganic P concentration in the bran nearly four-fold. Inheritance data of F 2 and F 4:6 families was inconsistent with a single-gene mutation and suggests the involvement of two or more genes. This low phytic acid wheat mutant is a genetic resource for studying the biology of seed phytic acid metabolism and wheat quality improvement.