Essays on Indices and Matching

In many decision problems, agents base their actions on a simple objective index, a single number that summarizes the available information about objects of choice independently of their particular preferences. The first chapter proposes an axiomatic approach for deriving an index which is objective and, nevertheless, can serve as a guide for decision making for decision makers with different preferences. Unique indices are derived for five decision making settings: the Aumann and Serrano (2008) index of riskiness (additive gambles), a novel generalized Sharpe ratio (for a standard portfolio allocation problem), Schreiber’s (2013) index of relative riskiness (multiplicative gambles), a novel index of delay embedded in investment cashflows (for a standard capital budgeting problem), and the index of appeal of information transactions (Cabrales et al., 2014). All indices share several attractive properties in addition to satisfying the axioms. The approach may be applicable in other settings in which indices are needed. The second chapter uses conditions from previous literature on complete orders to generate partial orders in two settings: information acquisition and segregation. In the setting of information acquisition, I show that the partialorder prior independent investment dominance (Cabrales et al., 2013) refines Blackwell’s partial order in the strict sense. In the segregation setting, I show that without the requirement of completeness, all of the axioms suggested in Frankel and Volij (2011) are satisfied simultaneously by a partial order which refines the standard partial order (Lasso de la Vega and Volij, 2014). In the third and fourth chapters, I turn to examine matching markets. Although no stable matching mechanism can induce truth-telling as a dominant strategy for all participants (Roth, 1982), recent studies have presented conditions under which truthful reporting by all agents is close to optimal (Immorlica and Mahdian, 2005; Kojima and Pathak, 2009; Lee, 2011). The third chapter demonstrates that in large, balanced, uniform markets using the Men-Proposing Deferred Acceptance Algorithm, each woman’s best response to truthful behavior by all other agents is to truncate her list substantially. In fact, the optimal degree of truncation for such a woman goes to 100% of her list as the market size grows large. Comparative statics for optimal truncation strategies in general one-to-one markets are also provide: reduction in risk aversion and reduced correlation across preferences each lead agents to truncate more. So while several recent papers focused on the limits of strategic manipulation, the results serve as a reminder that without preconditions ensuring truthful reporting, there exists a potential for significant manipulation even in settings where agents have little information. Recent findings of Ashlagi et al. (2013) demonstrate that in unbalanced random markets, the change in expected payoffs is small when one reverses which side of the market “proposes,” suggesting there is little potential gain from manipulation. Inspired by these findings, the fourth chapter studies the implications of imbalance on strategic behavior in the incomplete information setting. I show that the “long” side has significantly reduced incentives for manipulation in this setting, but that the same doesn’t always apply to the “short” side. I also show that risk aversion and correlation in preferences affect the extent of optimal manipulation as in the balanced case.Business Economic

Gender segregation in technological undergraduate studies in the University of the Basque Country (UPV/EHU)

In this work we study the gender segregation in technological undergraduate studies in the University of The Basque Country (UPV/EHU). For this study we use the data of new admissions at the UPV/EHU. They are from the time period of the years 2003-2013. We focus on the first and last year to check if the segregation has changed over these ten years. We build segregation curves within the Lorenz approach. Our results show that the gender segregation in technological undergraduate studies in the University of the Basque Country has increased over the last ten years. We also show that the distribution between men and women has changed.

Genomic mapping of social behavior traits in a F2 cross derived from mice selectively bred for high aggression

BACKGROUND: Rapid response to selection was previously observed in mice selected for high levels of inter-male aggression based on number of attacks displayed in a novel social interaction test after isolation housing. Attack levels in this high aggression line (NC900) increased significantly within just four generations of selective breeding, suggesting the presence of a locus with large effect. We conducted an experiment using a small (n ≈ 100) F(2 )cross between the ICR-derived, non-inbred NC900 strain and the low aggression inbred strain C57BL/6J, genotyped for 154 fully informative SNPs, to determine if a locus with large effect controls the high-aggression selection trait. A second goal was to use high density SNP genotyping (n = 549,000) in the parental strains to characterize residual patterns of heterozygosity within NC900, and evaluate regions that are identical by descent (IBD) between NC900 and C57BL/6J, to determine what impacts these may have on accuracy and resolution of quantitative trait locus (QTL) mapping in the F(2 )cross. RESULTS: No evidence for a locus with major effect on aggressive behavior in mice was identified. However, several QTL with genomewide significance were mapped for aggression on chromosomes 7 and 19 and other social behavior traits on chromosomes 4, 7, 14, and 19. High density genotyping revealed that 28% of the genome is still segregating among the six NC900 females used to originate the F(2 )cross, and that segregating regions are present on every chromosome but are of widely different sizes. Regions of IBD between NC900 and C57BL/6J are found on every chromosome but are most prominent on chromosomes 10, 16 and X. No significant differences were found for amounts of heterozygosity or prevalence of IBD in QTL regions relative to global analysis. CONCLUSIONS: While no major gene was identified to explain the rapid selection response in the NC900 line, transgressive variation (i.e. where the allele from the C57BL/6J increased attack levels) and a significant role for dominant gene action were hallmarks of the genetic architecture for aggressive behavior uncovered in this study. The high levels of heterozygosity and the distribution of minor allele frequency observed in the NC900 population suggest that maintenance of heterozygosity may have been under selection in this line

Genomic mapping of social behavior traits in a F2 cross derived from mice selectively bred for high aggression

Abstract Background Rapid response to selection was previously observed in mice selected for high levels of inter-male aggression based on number of attacks displayed in a novel social interaction test after isolation housing. Attack levels in this high aggression line (NC900) increased significantly within just four generations of selective breeding, suggesting the presence of a locus with large effect. We conducted an experiment using a small (n ≈ 100) F2 cross between the ICR-derived, non-inbred NC900 strain and the low aggression inbred strain C57BL/6J, genotyped for 154 fully informative SNPs, to determine if a locus with large effect controls the high-aggression selection trait. A second goal was to use high density SNP genotyping (n = 549,000) in the parental strains to characterize residual patterns of heterozygosity within NC900, and evaluate regions that are identical by descent (IBD) between NC900 and C57BL/6J, to determine what impacts these may have on accuracy and resolution of quantitative trait locus (QTL) mapping in the F2 cross. Results No evidence for a locus with major effect on aggressive behavior in mice was identified. However, several QTL with genomewide significance were mapped for aggression on chromosomes 7 and 19 and other social behavior traits on chromosomes 4, 7, 14, and 19. High density genotyping revealed that 28% of the genome is still segregating among the six NC900 females used to originate the F2 cross, and that segregating regions are present on every chromosome but are of widely different sizes. Regions of IBD between NC900 and C57BL/6J are found on every chromosome but are most prominent on chromosomes 10, 16 and X. No significant differences were found for amounts of heterozygosity or prevalence of IBD in QTL regions relative to global analysis. Conclusions While no major gene was identified to explain the rapid selection response in the NC900 line, transgressive variation (i.e. where the allele from the C57BL/6J increased attack levels) and a significant role for dominant gene action were hallmarks of the genetic architecture for aggressive behavior uncovered in this study. The high levels of heterozygosity and the distribution of minor allele frequency observed in the NC900 population suggest that maintenance of heterozygosity may have been under selection in this line

Nomination Committee, Gender Diverse Board and Organisational Outcomes: An Australian Perspective

The thesis is structured around a three-paper format. These papers examine three distinct but interrelated aspects of corporate gender diversity. It provides; (1) a comprehensive review of corporate gender diversity (theories, studies, and regulation); (2) examines impact of nomination committee existence and attributes on corporate board gender diversity; and (3) the impact of gender diverse board on earnings quality. All three papers of the thesis highlight diverse aspects and the significance of corporate female leadership

Inimtekkeliste hüdromorfoloogiliste muutuste mõju vooluvete seisundile suurselgrootute järgi Eestis (Euroopa, Balti ökoregioon)

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Inimesed on muutnud väga paljude vooluveekogude hüdromorfoloogiat: voolukiirust, põhja iseloomu ja voolusängi kuju. Sellised muutused on nende veekogude elustikku sageli oluliselt mõjutanud. Enamik Eesti jõgedest on vähemalt mingis osas õgvendatud, paljud ka paisutatud. Õgvendamise käigus kaevatakse kogu vooluveekogu või mõni selle osa sirgeks. Tulemuseks on voolukiiruse ja põhja iseloomu ühtlustumine. Paisutamise käigus muudetakse kiirevooluline jõelõik seisuveeliseks järveks, kuhu setib muda. Suurselgrootud on palja silmaga nähtavad, veekogude põhjal, taimedel, setete sees või veepinnal elavad loomad. Neid on veekogude seisundi indikaatoritena kogu maailmas palju kasutatud, sest nad reageerivad ennustatavalt mitmesugusele inimtegevusele, eriti orgaanilisele ja happelisele veereostusele. Pole selge, kas Eestis seni kasutatav vooluvete seisundi hindamissüsteem suurselgrootute järgi sobib ka hüdromorfoloogiliste muutuste usaldusväärseks iseloomustamiseks. Praeguse doktoritöö eesmärgiks oli hinnata paisutamise ja õgvendamise mõju vooluvete suurselgrootute seisundile. Selleks kasutati nii senist hindamissüsteemi kui töötati välja uus hindeks hüdromorfoloogiliselt muudetud jõeosade üle otsustamiseks. Paljud suurselgrootud osutusid vooluvete paisutamise ja/või õgvenduse suhtes oluliselt tundlikeks. Uus indeks MESH võimaldas usaldusväärselt hinnata paisjärvede mõju suurselgrootutele.Alteration of hydromorphology as a consequence of human activities (e.g. damming and channelization) poses a significant threat to habitat quality and in turn to riverine communities. Taxonomic composition of benthic macroinvertebrates has been widely used as an indicator of running water quality. It is not clear whether the metrics included in the Estonian multimetric index of biological quality reflect hydromorphological disturbances appropriately. The aims of this Theses were 1) to assess the effect of damming and channelization on stream biological quality using current national multimetric index, and 2) to develop new index specially for hydromorphologically degraded streams. Most macroinvertebrate-based indices of biological quality, belonging to the corresponding national multimetric index, were significantly and negatively influenced both by damming and channelization. The new index The MESH distinguished reliably the above-dam macroinvertebrate communities from those of the other area

Essays on peer effects in social groups and information misperception

This thesis consists of three chapters. Chapter 1 develops a model that studies the interaction of two forces in the formation of social groups: the preference for high quality peers and the desire for status among one’s peers. I present a characterization of fundamental properties of equilibrium group structures in a perfect information, simultaneous move game when group membership is priced uniformly and cannot directly depend on type. While equilibrium groups generally exhibit some form of assortative matching between individual type and peer quality, the presence of status concern reduces the potential degree of sorting and acts as a force for greater homogeneity across groups. Chapter 2 expands on this framework and analyses the effect of status concern for the provision of groups under different market structures. I particularly focus on the implications for segregation and social exclusion. I find that status concern reduces the potential for and benefit from segregation - both for a social planner and a monopolist - but the interaction of preference for rank and status can make the exclusion of some agents a second-best outcome. Social exclusion might occur even if the market is served by competitive firms. Chapter 3 studies how two fundamental mistakes in information processing affect the welfare ranking of information experiments. In the spirit of Blackwell (1951), the binary ranking of informative action profiles is analysed under different classes of perception distortions. By themselves, an agent’s tendency to misinterpret signals and the degree to which the prior deviates from the truth reduce expected utility in a model where payoff relevant actions also generate informative signals. However, experiments can be affected to different degrees. Necessary and sufficient conditions for when any binary ranking of action profiles can be reversed are provided. As a consequence, different types of mistakes can interact in non-obvious ways such that an agent might be better off suffering from both rather than just one. The chapter concludes with a characterization when such positive interaction is possible and illustrates the implications in an investment setting with costly information acquisition

Genomic Prediction: Progress and Perspectives for Rice Improvement

Genomic prediction can be a powerful tool to achieve greater rates of genetic gain for quantitative traits if thoroughly integrated into a breeding strategy. In rice as in other crops, the interest in genomic prediction is very strong with a number of studies addressing multiple aspects of its use, ranging from the more conceptual to the more practical. In this chapter, we review the literature on rice (Oryza sativa) and summarize important considerations for the integration of genomic prediction in breeding programs. The irrigated breeding program at the International Rice Research Institute is used as a concrete example on which we provide data and R scripts to reproduce the analysis but also to highlight practical challenges regarding the use of predictions. The adage “To someone with a hammer, everything looks like a nail” describes a common psychological pitfall that sometimes plagues the integration and application of new technologies to a discipline. We have designed this chapter to help rice breeders avoid that pitfall and appreciate the benefits and limitations of applying genomic prediction, as it is not always the best approach nor the first step to increasing the rate of genetic gain in every context