physical appearance and earnings further evidence the literature contains numerous studies on earnings differentials based on age race and gender comparatively few studies have examined differences in labour market success related to physical appearance using three waves of data collected at two organizations this paper tested for earnings differentials among workers based on their self reported appearance significant earnings premiums for attractiveness were found for women but not for men

games for electricity traders understanding risk in a deregulated industry abstract we illustrate and discuss the use of a computer based learning environment known as a microworld for training agents in the colombian electricity market as the market operator was concerned with efficiency in the electricity spot market because of an insufficient number of participants they commissioned a tool that could help potential participants to learn about both market operation as well as the risk management it involved by making the industry more transparent it was intended that a larger number of traders and companies would participate in the market making it more efficient we describe the development and use of this tool which is based on system dynamics and gaming

informational constraints and the overlapping generations model folk and anti folk theorems this paper analyses the sustainability of inter generational transfers in samuelson s consumption loan model when agents are imperfectly informed about past events we find that with mild informational constraints transfers cannot be supported by pure strategy equilibria mixed strategies allow transfers to be sustained even if agents have little information so that a version of the folk theorem holds however these equilibria are not robust if each agent s utility function is subjected to a small random perturbation as in harsanyi 1973 these mixed strategy equilibria unravel and only the zero transfer allocation survives as the unique rationalizable outcome this result is an example of mixed strategy equilibrium of an extensive form game which cannot be purified

using the decentralized and liberalized electricity market microworld lemm as an educational tool abstract decentralized and liberalized electricity market involves a great deal of interdisciplinary concepts including economic commercial environmental and technological issues consequently the system is complicated accordingly nowadays introductory courses focusing on the electricity market dynamics have been added to the curriculum at many universities however as the electricity market dynamics are complicated it is not straightforward for students to understand a teaching tool to assist students to better understand strategic behaviors in the market is thus in high demand due to these reasons liberalized electricity market microworld lemm incorporating a system dynamics based simulation model is developed the lemm s contribution to the students learning and understanding of the decentralized and liberalized electricity market dynamics have been explored by organizing game sessions with the lemm for totally 49 students who participated in energy policy and planning course in bogazici university the findings obtained from the exploratory study reveal that the students improved their understanding of the liberalized and decentralized electricity market through the game session with the lemm in this paper the general characteristics of the lemm and the underlying model are presented the microworlds particularly the lemm s potential contribution to learning and teaching is discussed

beauty and the labor market the authors examine the impact of looks on earnings using interviewers ratings of respondents physical appearance plain people earn less than average looking people who earn less than the good looking the plainness penalty is 5 to 10 percent slightly larger than the beauty premium effects for men are at least as great as for women unattractive women have lower labor force participation rates and marry men with less human capital better looking people sort into occupations where beauty may be more productive but the impact of individuals looks is mostly independent of occupation suggesting the existence of pure employer discrimination copyright 1994 by american economic association

cooperation in ongoing organizations this paper argues that overlapping games can provide a natural theory of long lived organizations it shows that participation in organizations of infinite duration changes the incentives of agents with finite lives and will induce more cooperation than a static model would predict after developing the general theory we apply it to the description of career paths in organizations and show that it can be optimal to give the youngest workers the most arduous tasks

stochastic olg models market structure and optimality for a general class of pure exchange olg economies under uncertainty we provide a complete characterization of the efficency properties of competitive equilibria when markets are only sequentially complete and the criterion of efficency is conditional pareto optimality we also consider a particular case in which markets fail to be even sequentially complete and provide a characterization when the criterion of efficency is weakened to ex post pareto optimality

beauty in the classroom are german students less blinded putative pedagogical productivity due to professors pulchritude peculiar or pervasive given that instructional student ratings measure differences in pedagogical productivity this study examines whether perceived attractiveness of german university teachers impact on these differences apart from some refinements and adjustments to idiosyncracies of the german system of higher learning the quantitative analysis widely follows the strategy of the seminal work by hamermesh and parker 2005 based on us data in comparison to findings for the usa perceived attractiveness of teachers is found to have if at all only a weakly significant and quantitatively less important impact on the evaluation outcomes

university quality and labour market outcomes this paper uses proxies for university quality derived from the research assessment exercise and the teaching quality assurance agency to assess the impact of university quality on the labour market outcomes of a cohort of uk graduates the impacts on job quality and earnings were mainly limited to graduates in particular disciplines or those obtaining poor degrees from good universities the results suggest that after controlling for pre entry qualifications labour market outcomes for most graduates depended more on the subject studied and degree classification awarded than on the university attended

from planning to strategy in the electricity industry abstract as more utility markets are deregulated and competition is introduced there is an increasing need to understand how the planning methods used under monopoly have to change to take the new deregulated environment into account although this might seem relatively trivial it has been a major problem for a large number of utilities which have continued using the same planning approaches that they used when they were monopolies in this paper we first describe the environment which under monopoly conditions gave rise to the use of mainly operational research methods for planning we then argue that deregulation has changed the fundamental assumptions making the planning methods used under monopoly less useful after deregulation finally we review a number of methods that utilities should consider using when they formulate strategy in deregulated markets

beauty productivity and discrimination lawyers looks and lucre we propose models with an ascriptive characteristic generating earnings differentials and causing sectoral sorting allowing us to distinguish among sources producing such differentials we use longitudinal data on a large sample of graduates from one law school and measure beauty by rating matriculation photographs 1 betterlooking attorneys who graduated in the 1970s earned more than others after 5 years of practice an effect that grew with experience 2 attorneys in the private sector are better looking than those in the public sector differences that rise with age these results support theories of dynamic sorting and customer behavior

cooperation in microcredit borrowing groups identity sanctions and reciprocity in the production of collective goods cooperation to produce collective goods is widespread in society and yet so is its failure theorists have identified competing mechanisms for facilitating group cooperation including group identity sanctions and reciprocity here i use empirical data to explore how these mechanisms influence cooperation in the natural laboratory of microcredit borrowing groups microcredit makes loans to high risk borrowers through borrowing groups in which individuals access to credit is dependent on the behavior of other members of the group thereby creating a social dilemma for members and an opportunity to observe cooperation in real world groups by analyzing both collective goods production loans and compliance repayment i find that the competing mechanisms have differential effects group identity sanctions and reciprocity are all associated with more borrowing in the group only reciprocity however limits loan delinquency and is associated with group longevity suggesting both that collective goods p

sensitivity of reserve margin to factors influencing investment behaviour in the electricity market of england and wales abstract the electricity generation and distribution industries of england and wales have recently undergone major re structuring as part of the privatization process of taking them out of the public sector on the generation side three major companies have been created which compete both with each other and with the new independent companies who are expected to enter the market trading between generators and distributors is controlled centrally by a pool system which attempts to ensure the optimal operation of the system in the short term and gives a pricing signal for longer term investment this pricing signal depends upon an a priori loss of load probability this paper is intended to provide insights into how the investment in capacity for generation could evolve according to various regulatory conditions economic assumptions degrees of competition and the strategic behaviour of the separate companies using a system dynamics approach a simulation model of investment is developed to generate insights into the volatility of the reserve margin variations in the loss of load probability and the various market share scenarios the degree of uncertainty in the demand the amount of information exchange between competitors and the degree of foresight in planning are considered as well as different financial or market share objectives for companies

a repeated game with finitely lived overlapping generations of players abstract this paper analyzes infinitely repeated noncooperative games where the players have finite but overlapping terms thus the nature of the game remains constant but the identity of the players changes over time this type of scenario depicts the situation facing firm managers in regulated or oligopolistic environments despite finite lives which lead players to always choose opportunistic actions at the end of their careers it is shown that there are equilibria where cooperative behavior emerges in this noncooperative setting further a folk theorem result is obtained any individually rational payoffs can be realized as a subgame perfect equilibrium journal of economic literature classification numbers 022 026

cooperation in stochastic olg games abstract this paper builds on cremer s quart j econ 101 1986 33 seminal analysis which shows that almost complete cooperation can be achieved as an equilibrium in a game played by overlapping generations of players if the institution in which players cooperate is infinitely lived we analyze a similar model in which the costs of cooperation are subject to random shocks even if these random shocks are very small the range of parameters for which cooperation can be sustained is decreased considerably in comparison to the deterministic case furthermore we show how the efficient outcome can be approximated if the level of cooperation can be varied continuously and the cooperation technology has decreasing or constant returns to scale while this is not possible in the case of increasing returns to scale

repeated games played by overlapping generations of players the present paper tries to explain cooperative behaviour in an organization run by a sequence of long but finitely lived agents we show that the folk theorem holds for infinitely repeated games with overlapping generations of finitely lived players any mutually beneficial outcome can approximately be sustained if the player s life span and the overlapping periods are long enough the result is stronger than the usual folk theorems in that it employs no assumption on the stage game such as the full dimensionality of payoff set or multiplicity of equilibria

asset markets and equilibrium processes the failure of the asset market to be complete causes serial dependence in output and prices which is suboptimal we consider an economy with white noise shocks when the asset market is complete an optimal competitive allocation inherits this strong stationarity when the asset market is only sequentially complete prices and output necessarily display serial dependence at equilibrium the further incompleteness of a monetary economy explains co movements in real and nominal variables

a decision support tool for the analysis of pricing investment and regulatory processes in a decentralized electricity market abstract after the liberalization of the electricity generation industry capacity expansion decisions are made by multiple self oriented power companies unlike the centralized environment decision making of market participants is now guided by price signal feedbacks and by an imperfect foresight of the future market conditions and competitor actions that they will face in such an environment decision makers need to better understand long term dynamics of the supply and demand sides of the power market in this study a system dynamics model is developed to better understand and analyze the decentralized and competitive electricity market dynamics in the long run the developed simulation model oversees a 20 year planning horizon it includes a demand module a capacity expansion module a power generation module an accounting and finance module various competitors a regulatory body and a bidding mechanism many features singularities and tools of decentralized markets such as capacity withholding enforced divestment long term contracts price elastic demands incentives disincentives are also incorporated into the model public regulators and power companies are potential users of the model for learning and decision support in policy design and strategic planning results of scenario analysis are presented to illustrate potential use of the model

intertemporal transfer institutions abstract we consider a single commodity overlapping generations model where at a cost institutions can be created or transformed to carry out intergenerational transfers we analyze the game with both strategic and cooperative methods characterizing the unique stationary equilibrium as well as the set of transfer institutions that belong to the core which we show to coincide with the consistent core we conclude that as long as the creation of an institution is costly it is possible to sustain positive transfers though those will be below the optimal level moreover the lower the costs the more efficient the transfer will be journal of economic literature classification numbers c71 c72 d23 e21 h55

rational expectations in the overlapping generations model abstract this paper reports results on the character of the rational expectations equilibria of a stochastic overlapping generations model with heterogenous markets the model considered is a stationary overlapping generations model in which the endowments of young agents are subject to i i d random shocks the main result shown is that if there are l 1 commodities traded in every period then for most preferences the rational expectations equilibrium stochastic process of prices and allocations necessarily exhibits serial correlation this is in marked contrast to the one commodity model in which there always exists an equilibrium which is measure isomorphic to the endowment process