The Natural Rate in a Share Economy

Will the natural rate 0f unemployment be lower in the share economy described by Martin Weitzman than in a wage economy? We examine this question for a search economy with an equilibrium unemployment rate, a version 0f Salop's (1979) quits model. Equilibrium unemployment is the same in both economies. We also examine firms' short-run adjustment to shocks. Share-economy firms adjust output less than wage-economy firms for both demand shocks and labor-supply shocks. Depending on whether rapid output adjustment is stabilizing, a share economy may be more or less stable than a wage economy

Application of Market Anti-inflation Plans in the Transition to a Market Economy

How can the former socialist countries' transition to a market economy be made less painful and more effective? We propose the use of incentive policies to stabilize prices and output. This would reduce former planned economies' tendency for output to fall and prices to rise as firms and workers take advantage of their market power. The policy allows firms individual pricing freedom while giving assurance that the price level will be stable. It also can break the vicious circle of reduced aggregate output by setting fixed level of output.Socialists

The Natural Rate in a Share Economy

Will the natural rate 0f unemployment be lower in the share economy described by Martin Weitzman than in a wage economy? We examine this question for a search economy with an equilibrium unemployment rate, a version 0f Salop's (1979) quits model. Equilibrium unemployment is the same in both economies. We also examine firms' short-run adjustment to shocks. Share-economy firms adjust output less than wage-economy firms for both demand shocks and labor-supply shocks. Depending on whether rapid output adjustment is stabilizing, a share economy may be more or less stable than a wage economy

Mitochondrial phylogeography and demographic history of the Vicuña: implications for conservation

The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275 000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22°S) dry Andes 14–12 000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29°S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts

Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach

Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well

Livestock and the functional habitat of vicuñas in Ecuador : a new puzzle

Includes supplementary Appendix S1.Whether interactions between wildlife and livestock are competitive or facilitative is context dependent. Intermediary factors that explain how context (seasonal or regional characteristics of the ecological community) affects these interactions are rarely reported. We compared activity time and density in vicuñas (Vicugna vicugna) introduced into the Chimborazo Faunal Production Reserve (CFPR), Ecuador, to describe how they interact with livestock. We compared vicuña density in wetlands and uplands (two landscape structures) with and without livestock (two conditions) using an isodar approach. We measured, over two seasons, vicuña forage abundance, composition, preference and accessibility, time vicuñas spent vigilant, and their flight distances on approach. We tested optimal foraging theory relating to the hypothesis that time mediates behavior, and found that vicuñas were no less frequently vigilant, nor were flight distances greater, during a wet season or in habitats of greater forage abundance and accessibility. We also found no evidence that vicuña behavior was density dependent; instead, we found that more time was spent vigilant by vicuñas when they foraged near livestock in rainy regions during the dry season. Although forage abundance was similar throughout CFPR during a dry season, better forage quality in areas occupied by livestock may constitute an effect of their facilitating vicuñas. A puzzling finding, because it was not explained by any of the other variables we measured, was that at low densities vicuñas selected habitat irrespective of livestock, and where their density was higher, it was doubly so adjacent to livestock. We conclude that in the CFPR, spatial heterogeneity in habitat quality determines the interactions between livestock and vicuñas. To support recommendations that minimize competition between wildlife and livestock, and to expand on descriptions of the contexts that determine the direction of species interactions, future study may require a wider sampling of the densities of sympatric large herbivores in general, and, in the CFPR, a closer resolution of spatial heterogeneity in forage plant quality

Sons of low-ranking female rhesus macaques can attain high dominance rank in their natal groups

Five adult and subadult sons of middle- and low-ranking female rhesus macaques ( Macaca mulatta ) were observed to hold high dominance rank in their natal groups during a 12-month study at Cayo Santiago, Puerto Rico. Three of these males also experienced high mating success during at least one mating season. These findings contrast with all previously published accounts of rank acquisition by natal male rhesus macaques in provisioned colonies, and they present a challenge to the hypothesis that natal transfer functions to increase male access to fertile females.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41609/1/10329_2006_Article_BF02382622.pd

Different preferences, different politics: A demand-and-structure explanation

While Theodore Lowi's typology of issues and policies is widely agreed to distinguish different forms of legislative politics, his explanation for the categories has not been fully persuasive. This paper uses demand theory to analyze the different politics described by Lowi. Demand theory can illuminate many questions in legislative politics; it provides cardinal measures of valuation and methods of estimating those values statistically. Different distributions of political demand across legislators cause differences in legislative politics and institutional structure similar to those Lowi observed. Demand theory provides a more general theory of different types of politics and several testable differences from Lowi's typology. Evidence from case studies is analyzed and roll-call voting studies and the implications are compared with those of Lowi's theory. In several cases, where issues have become "ideological" and "redistributive" in the 1980s, the politics have changed, as the demand model predicts and Lowi's theory does not

Different preferences, different politics: A demand-and-structure explanation

While Theodore Lowi's typology of issues and policies is widely agreed to distinguish different forms of legislative politics, his explanation for the categories has not been fully persuasive. This paper uses demand theory to analyze the different politics described by Lowi. Demand theory can illuminate many questions in legislative politics; it provides cardinal measures of valuation and methods of estimating those values statistically. Different distributions of political demand across legislators cause differences in legislative politics and institutional structure similar to those Lowi observed. Demand theory provides a more general theory of different types of politics and several testable differences from Lowi's typology. Evidence from case studies is analyzed and roll-call voting studies and the implications are compared with those of Lowi's theory. In several cases, where issues have become "ideological" and "redistributive" in the 1980s, the politics have changed, as the demand model predicts and Lowi's theory does not