forward contracts for the operation of an electricity industry under spot pricing a study is reported of the use of forward contracts as risk instruments for electricity industries operating under spot pricing forward contracts involve financial transactions or commitments which relate to a physical trade at a later time instance price setting and appropriate participant responses are discussed simulation studies are used to demonstrate that forward contracts offer participants an opportunity to reduce their risk exposure without removing the incentive to respond to higher spot prices

the determinants of teenage schooling in jamaica rich vs poor females vs males the belief that schooling is an important way to reduce poverty and increase social mobility has lead to large government sponsored investment in education in developing countries jamaica has an impressive literacy and primary enrolment rate yet the ability of its secondary school system to enhance social mobility and reduce inequality is limited regression results from a nationally representative household survey show that family background variables parental education and income are important determinants of secondary school enrolment and income is the single most important determinant of enrolment in an elite high school with the impact being twice as large for females part of the income effect is shown to represent unobserved community heterogeneity one conclusion is that the recent cost sharing education policy of the jamaican government if applied selectively to the elite academic high schools will fall disproportionately upon rich households

favorite son specialized child laborers and students in poor ldc households abstract though prior theoretical models of child labor nominally contain households with multiple children they treat all children as identical in their returns to labor market and education activities in actuality households with identical twins are the exception and inherent heterogeneity implies different returns for children we construct a theoretical model that allows child heterogeneity and bilateral altruism our model illuminates potential inefficiencies in the time allocation of children across labor market obligations and education opportunities in poor households when intra household talent differentials across children are great an inefficient reverse specialization may arise and partial bans on child labor will increase efficiency

reanalysis of nash equilibrium bidding strategies in a bilateral electricity market we reanalyze a bilateral electricity market model previously presented in where suppliers own multiple generators we clarify some implicit assumptions in the model and prove that under one detailed specification of the assumptions the previously suggested nash equilibria for the model are inconsistent with the definition of nash equilibrium we discuss the implications and comment on the relationship to multiple unit auction theory

durable goods oligopoly abstract this paper models a durable goods oligopoly as a differential game two cases are treated sales where firms cannot lease but must sell the good in question and leasing where firms do not sell but only rent in the sales case firms face increasing marginal cost of production and the good in question depreciates for this case a rational expectations feedback nash equilibrium is constructed for which monopoly or oligopoly output is less than the efficient level this gap between oligopoly and competitive output diminishes as the number of firms increases when firms can only lease the good the good is assumed not to depreciate and the monopoly level of steady state output is compared with the level of steady state output for a feedback equilibrium duopoly for this case the duopoly equilibrium has steady state output that is less than the corresponding efficient level but greater than the monopoly level the leasing model is shown to be isomorphic to the adjustment cost duopoly model of driskill and mccafferty journal of economic theory 49 1989 324 338

market equilibrium under incomplete and imperfect information in bilateral electricity markets in contrast to the centralized pool model bilateral markets present a decision making situation in which information plays a major role along with the physical and operative constraints of the network we propose a model that includes network constraints for competitive bilateral electricity markets based on an evolutionary bipartite complex network in which the nodes and weighted links represent the players and transactions respectively the strong stable equilibrium of the network is applied to detect possible market equilibria obtained through a dynamic game with incomplete and imperfect information in which the players form an evolutionary network while trying to maximize their own utilities the model is conceptually illustrated with a four bus test system and then applied to the ieee30 test system to analyze the impact of the transmission network and information on the equilibria and market performance

nash equilibrium bidding strategies in a bilateral electricity market this paper examines bidding strategies in a bilateral market in which generating companies submit bids to loads a load accepts electricity delivery from the generator with the lowest bid at its bid price as long as this price is not higher than the load s willingness to pay necessary and sufficient conditions of nash equilibrium ne bidding strategy are derived based on a generic generating cost matrix and the loads willingness to pay vector the study shows that in any ne efficient allocation is achieved furthermore all nash equilibria are revenue equivalent for the generators based on the necessary and sufficient conditions this problem is formulated as an optimal assignment problem network optimization techniques are applied to calculate ne bid prices for the generators

dynamic duopoly with congestion effects abstract we analyze duopolistic competition between horizontally differentiated firms selling durable goods or services subject to congestion at each point of time new customers buy one unit of the commodity from one of the firms by comparing present prices and future congestion rates we study the linear markov equilibrium of this game which exists and is unique when firms are not too different the existence of negative consumption externalities is shown to soften the price competition moreover we show that the firm with the larger capacity has at the steady state a larger market share a higher price and a lower congestion rate the price of an entrant decreases gradually after entry while the price of the incumbent rises the faster the speed of convergence to the steady state is the stronger is the congestion effect

congestion reducing investments and economic welfare in a hotelling model abstract we investigate optimal quality provision where quality is determined by congestion duopolists make congestion reducing investments and then compete in prices we find that an unregulated market leads to insufficient investment and that price cap below the equilibrium price eliminates this inefficiency

elicitation of honest preferences for the assignment of individuals to positions the problem of eliciting honest preferences from individuals who must be assigned to a set of positions is considered individuals know that they will be charged for the positions to which they are assigned a set of prices that provide no incentive for the individual to misrepresent his preferences is suggested it is shown that these prices constitute an element of the optimal solution to the dual of a linear programming assignment problem both the optimal allocation and the prices to be charged can be derived by solving two linear programming problems once preferences have been elicited the procedure can usefully be viewed as a simulation of a competitive market under conditions where such a market cannot be expected to function well it results in an efficient allocation where all resources are valued at their opportunity costs and consumer surplus is maximized its outcome thus has the desirable properties of competitive market equilibria

using game theory to analyze electric transmission pricing policies in the united states abstract us public policy towards the private electric power industry is moving away from restrictive regulation and towards promotion of competition alternative policies concerning access to and pricing of transmission are now being discussed similar issues may arise in europe as trade barriers fall our purpose is to show how game theory can help illuminate that debate and identify desirable policies game theory models are used to estimate the possible effects of various policies upon productive efficiency and the distribution of gains among sellers transmitters and buyers of power static cooperative models are used to calculate the possible outcomes of short run transmission games long run games in which the amount of transmission capacity is a decisition variable are modeled as dynamic noncooperative stackelberg games one conclusion is that under some conditions price regulation and mandatory access could hurt power buyers by removing incentives for building transmission capacity another conclusion is that under a system of voluntary access and price regulation it may be better to allow wheeling prices to exceed the marginal cost of transport rather than to risk losing the benefits of cooperation

financial bilateral contract negotiation in wholesale electricity markets using nash bargaining theory bilateral contracts are important risk hedging instruments constituting a major component in the portfolios held by many electric power market participants however bilateral contract negotiation is a complicated process as it involves risk management strategic bargaining and multi market participation this study analyzes a financial bilateral contract negotiation process between a generation company and a load serving entity in a wholesale electric power market with congestion managed by locational marginal pricing nash bargaining theory is used to model a pareto efficient settlement point the model predicts negotiation outcomes under various conditions and identifies circumstances in which the two parties might fail to reach an agreement both analysis and simulation are used to gain insight regarding how these negotiation outcomes systematically vary in response to changes in the participants risk preferences and price biases

genetic algorithm evolution of utility bidding strategies for the competitive marketplace this paper describes an environment in which distribution companies discos and generation companies gencos buy and sell power via double auctions implemented in a regional commodity exchange the electric utilities profits depend on the implementation of a successful bidding strategy in this research a genetic algorithm evolves bidding strategies as gencos and discos trade power a framework in which bidding strategies may be tested and modified is presented this simulated electric commodity exchange can be used offline to predict whether bid strategies will be profitable and successful it can also be used to experimentally verify how bidding behavior affects the competitive electric marketplace

network effects aftermarkets and the coase conjecture a dynamic markovian approach this paper investigates the expansion of the network of a monopolist firm that produces a durable good and is also involved in the corresponding aftermarket we characterize the markov perfect equilibrium of the continuous time dynamic game played by the monopolist and the forward looking consumers under the assumption that consumers benefit from the subsequent expansion of the network the paper contributes to the theoretical discussion on the validity of the coase conjecture analyzing whether coase s prediction that the monopolist serves the market in a twinkling of an eye remains valid in our setup we conclude that the equilibrium network development may actually be gradual contradicting coase s conjecture we find that a necessary condition for such a result is the existence of aftermarket network effects that accrue at least partly to the monopolist firm

quality and price personalization under customer recognition a dynamic monopoly model with contrasting equilibria abstract we present a model of market hyper segmentation where a monopolist acquires within a short time all information about the preferences of consumers who purchase its vertically differentiated products the firm offers a new price quality schedule after each commitment period lower consumer types may have an incentive to delay their purchases until next period to obtain a better introductory offer the monopolist counters this incentive by offering higher informational rents considering the dynamic game played by the monopolist and its customers we find that there is always a markov perfect equilibrium mpe in which the firm immediately sells the good to all customers offering the mussa rosen static equilibrium schedule to first time customers and getting full commitment profits however if the commitment period between two offers is long enough there is another mpe with gradual market expansion contrary to the coasian result for a durable good monopoly we find that in both equilibria the profit of the monopolist increases and the aggregate consumers surplus decreases as the interval of commitment shrinks the model yields policy implications for regulations on collection and storage of customers information

optimal electricity supply bidding by markov decision process the bidding decision making problem is studied from a supplier s viewpoint in a spot market environment the decision making problem is formulated as a markov decision process a discrete stochastic optimization method all other suppliers are modeled by their bidding parameters with corresponding probabilities a systematic method is developed to calculate transition probabilities and rewards a simplified market clearing system is also included in the implementation a risk neutral decision maker is assumed the optimal strategy is calculated to maximize the expected reward over a planning horizon simulation cases are used to illustrate the proposed method

bidding strategy of virtual power plant for participating in energy and spinning reserve markets part i problem formulation this paper addresses the bidding problem faced by a virtual power plant vpp in a joint market of energy and spinning reserve service the proposed bidding strategy is a non equilibrium model based on the deterministic price based unit commitment pbuc which takes the supply demand balancing constraint and security constraints of vpp itself into account the presented model creates a single operating profile from a composite of the parameters characterizing each distributed energy resources der which is a component of vpp and incorporates network constraints into its description of the capabilities of the portfolio the presented model is a nonlinear mixed integer programming with inter temporal constraints and solved by genetic algorithm ga

profit maximizing clubs abstract we study a nash equilibrium among profit maximizing clubs which choose facility size and admission price the number of clubs is endogenous entry is deterred whenever the symmetric nash equilibrium with one additional firm would yield negative profit equilibrium exists with positive profit the equilibrium price is higher than the congestion price and the equilibrium number of clubs is bounded below by one fewer than the efficient number in general there will be too much entry than too little one can choose an economy sufficiently large that the equilibrium price is within epsilon of the competitive price

understanding child labour beyond the standard economic assumption of monetary poverty child labour is pervasive across sub saharan africa the common assumption is that monetary poverty is its most important cause this paper investigates this hypothesis with empirical evidence by exploring structural geographic monetary demographic cultural seasonal and school supply factors simultaneously that can influence child labour it is a first attempt in the literature to combine quantitative with qualitative methods to identify a broader range of potential factors on the demand and supply side and at the micro and macro levels for why children work in agrarian economies like ghana interviews with the minister of education and with children enrich the multivariate regression results the multiple sources of child labour appear to include in particular the structure of the economy social norms and no returns to rural basic education policy responses are outlined especially on the demand side that are needed to help reduce harmful child labour that affects children s education and later opportunities

natural resource collection work and children s schooling in malawi abstract this paper presents results of research that investigates if long hours of work spent by children in fuel wood and water collection activities i e natural resource collection work influence the likelihood that a child aged 6 14 attends school potential endogeneity of resource collection work hours is corrected for using two stage conditional maximum likelihood estimation data from the 1997 1998 malawi integrated household survey ihs conducted by the malawi national statistics office nso in conjunction with the international food policy research institute ifpri are used the study finds that malawian children are significantly involved in resource collection work and their likelihood of attending school decreases with increases in hours allocated to this work the study further shows that girls spend more hours on resource collection work and are more likely to be attending school while burdened by this work consequently girls may find it difficult to progress well in school however girls are not necessarily less likely to be attending school results further show that presence of more women in a household is associated with a lower burden of resource collection work on children and a higher probability of children s school attendance finally the research shows that children from the most environmentally degraded districts of central and southern malawi are less likely to attend school and relatively fewer of them have progressed to secondary school compared to those from districts in the north

improving identification of demand side obstacles to schooling findings from revealed and stated preference models in two ssa countries summary efforts to expand primary education have shifted from a policy focus on supply building schools to demand side policies human capital theory posits that common demand side obstacles are high direct costs opportunity costs and low perceived benefits constructs that are difficult to measure empirically this study compares strategies to estimate obstacles to schooling through revealed and stated preferences using similar household survey data from two sub saharan african countries the typical determinants of schooling model underestimates demand side obstacles and gender differences and additional useful information for theory testing and policy is derived from analyzing parents stated preferences as well

depreciation erodes the coase conjecture if a durable good monopolist produces at constant marginal costs and the good depreciates there exists a family of strong markov perfect equilibrium smpe one member of this family entails instantaneous production of the level of stock produced in a competitive equilibrium this is consistent with the coase conjecture other smpe in the family entail steady state production at a stock level lower than in the competitive equilibrium there may be a jump to these steady states or they may be approached asymptotically monopoly profits are positive in these equilibria and the coase conjecture fails

price competition when consumer behavior is characterized by conformity or vanity it has long been recognized that the pleasure of consuming a good may be affected by the consumption choice of other consumers in some cases social pressures may lead to conformity in some others individuals may feel the need of exclusiveness under the form of vanity such externalities have proven to be important in several markets however the market implication of these externalities are still unclear to investigate them we propose to combine the consumption externality model and the spatial duopoly model when conformity is present but not too strong both firms remain in business but price competition is fiercer and results in lower prices the market share of the large firm increases with the population size as the population keeps rising the large firm may serve the entire market and set a price that has the nature of a limit price when conformity is strong enough different equilibria may exist in most of these equilibria a single firm captures the whole market at the other extreme when vanity is at work price competition is relaxed

studies of bilateral contracts with respect to steady state security in a deregulated environment under a deregulated environment electricity consumers and suppliers will be permitted to establish various bilateral service contracts the transmission company however will only have to honour and execute these bilateral contracts as far as the system design and operating conditions permit a fundamental question is to what extent the system security could affect these contracts and what kinds of system reinforcements will be required to meet the future contract needs this paper describes a series of studies modelling the bilateral contracts by using a transaction matrix t the concept of the transaction matrix is to expand the conventional load flow variables such as generations pg and loads pd into a 2 dimensional matrix t each element of t namely t sub ij corresponds to a bilateral contract between a supplier pg sub i and consumer pd sub j a generalized linear programming formulation is then proposed to solve various system operation and planning problems under a deregulated environment subjected to the steady state security constraints e g generation and line flow limits examples are presented to illustrate how to use this formulation to maximize any bilateral contract individual generation or groups of generations or to minimize the necessary correction needed for a proposed transaction matrix t sup 0 in order to comply with the security requirements other studies such as the use of monte carlo methods to study the behaviour of random bilateral contracts are also presented and discussed

optional forward contracts for electric power markets this paper extends the idea of callable forward contracts which are potentially useful as demand side interruptible load contracts to their supply side analogues together these contracts allow market participants to take advantage of flexibility in generation or consumption to obtain a monetary benefit while simultaneously removing the risk of market price fluctuations this paper also considers the effects of strategic behavior on the part of market participants in their contract sales purchase decisions

socioeconomic and demographic aspects of school enrollment and attendance in rural botswana as has been true for other african and non african mineral rich economies the most serious constraint on botswana s development to date has been the lack of human capital schapera notes that in traditional botswana schooling was conceived as a burden on the family because of both the new expenditures associated with schooling and the loss of the child s contribution to household production and income ashton notes that parents in botswana apparently failed to perceive the benefits of education 2 the situation has changed fundamentally since schapera and ashton wrote in the forties largely through government policy programs of school construction and teacher training schools have become relatively widespread the benefits of schooling are apparent in the labor market and are even more immediately evident at home schools often provide free meals and health care to their pupils however the schooling system may not be designed to serve sparsely populated areas completely this reflects in part the movement and social spread of botswana s rural population across villages lands and cattle posts moreover children especially in households with assets play a role in the household economy 3 as a consequence the indirect costs of schooling those noted by shapera may still be substantial in botswana today these costs in addition to the direct costs of transportation and uniforms may be prohibitive to the schooling of many children the evidence i present later shows that even primary schooling was not universal in botswana at the time of the 1974 rural income distribution survey on which this present study is based 4 this paper is to study the demographic and socioeconomic corre

why governments should invest more to educate girls abstract women and men often receive the same percentage increase in their wage rates with advances in schooling because these returns decline with more schooling the marginal returns for women will tend to exceed those for men especially in countries where women are much less educated the health and schooling of children are more closely related to their mother s education than father s more educated women work more hours in the market labor force broadening the tax base and thereby potentially reducing tax distortions these three conditions it is argued justify the disproportionate allocation of public expenditures toward women s education

modeling bilateral electricity markets a complex network approach in electricity markets a pool trading model with a power exchange pool is a typical market organization that attracts much more attention than a bilateral trading model to date quite a few papers have focused on bilateral trading models particularly those under network constraints this trend is due to the model s complexity in terms of the various trading patterns reflecting the self interested behavior of the market participants striving to find potentially profitable transactions in this paper we propose a new approach based on complex networks suitable for assessing different aspects of bilateral market this work strives to analyze the bilateral trading patterns in the electricity markets where physical network constraints need to be considered for the feasible and secure operation of the power systems the goal of the work is to find the stable network structures that can be used to anticipate possible bilateral transactions in the real market place and to provide a novel and applicable approach to studying the bilateral model in electricity markets the proposed approach has been tested on several test systems in which the transmission network structure of the market that accommodates the transactions is considered the proposed model is illustrated with examples using a four bus test system the ieee 30 bus and the ieee 118 bus test systems

child labor and household wealth theory and empirical evidence of an inverted u some studies on child labor have shown that at the level of the household greater land wealth leads to higher child labor thereby casting doubt on the hypothesis that child labor is caused by poverty this paper argues that the missing ingredient may be an explicit modeling of the labor market we develop a simple model which suggests the possibility of an inverted u relationship between land holdings and child labor using a unique data set that has child labor hours it is found that controlling for child household and village characteristics the turning point beyond which more land leads to a decline in child labor occurs around 4 ac of land per household c 2009 published by elsevier b v

price taker bidding strategy under price uncertainty this paper provides a framework to obtain the optimal bidding strategy of a price taker producer an appropriate forecasting tool is used to estimate the probability density functions of next day hourly market clearing prices this probabilistic information is used to formulate a self scheduling profit maximization problem that is solved taking advantage of its particular structure the solution of this problem allows deriving a simple yet informed bidding rule results from a realistic case study are discussed in detail

transmission analysis by nash game method this paper describes an open access transmission method for maximizing profits in a power system the proposed method is based on the nash bargaining game for power flow analysis in which each transaction and its optimal price are determined to optimize the interests of individual parties transmission losses are considered by the proposed method and test cases and results are discussed to present the merits of the proposed method

the value and allocation of time in rural botswana abstract time use data indicate that there is substantial surplus labor in rural areas of botswana with the incidence of underutilization varying by age sex and asset position time allocations are influenced by economic incentives i e income and productivity effects the more productive capital the household has the more productive work its members perform particularly its children the positive productivity effect of capital on economic work somewhat outweighs its negative income effect time allocations also are constrained by a culturally determined division of labor by age and sex which however shows some flexibility at the margin

expenditure behavior and children s welfare an analysis of female headed households in jamaica abstract evidence from jamaica shows that the sex and union status of the household head can have a significant influence on household expenditure behavior with implications for individual household members while the presence of a female decision maker generally increases the share of the household budget allocated to child and family goods female headed households fhhs also spend more on adult wear and less on health lower health expenditures are partially offset by the differential use of other health inputs in fhhs these differences in resource allocation may explain why poorer fhhs do not necessarily have lower children s outcomes in developing countries

large shareholders monitoring and ownership dynamics toward pure managerial firms abstract we study ownership dynamics when the manager and the large shareholder both risk neutral simultaneously choose effort and monitoring level respectively to serve their non congruent interests we show that there is a wedge between the valuation of shares by atomistic shareholders and the large shareholder s valuation at the markov perfect equilibrium the large shareholder divests her shares if the incongruence of their interests is mild divestment is drastic all her shares are sold immediately if their interests diverge sharply the divestment is gradual in order to prevent a sharp fall in share price in the limit the firm becomes purely managerial

studies of bilateral contracts with respect to steady state security in a deregulated environment of electricity supply under a deregulated environment electricity consumers and suppliers will be permitted to establish various bilateral service contracts the transmission company however will only have to honour and execute these bilateral contracts as far as the system design and operating conditions permit a fundamental question is to what extent the system security could affect these contracts and what kinds of system reinforcements will be required to meet the future contract needs this paper describes a series of studies modelling the bilateral contracts by using a transaction matrix t the concept of the transaction matrix is to expand the conventional load flow variables such as generations pg and loads pd into a 2 dimensional matrix t each element of t namely t sub ij corresponds to a bilateral contract between a supplier pg sub 1 and consumer pd sub j a generalized linear programming formulation is then proposed to solve various system operation and planning problems under a deregulated environment subjected to the steady state security constraints e g generation and line flow limits examples are presented to illustrate how to use this formulation to maximize any bilateral contract individual generation or groups of generations or to minimize the necessary correction needed for a proposed transaction matrix t spl deg in order to comply with the security requirements other studies such as the use of monte carlo methods to study the behaviour of random bilateral contracts are also presented and discussed it was concluded that the proposed methodology will be an effective tool to study the intricate relationships between the bilateral contracts and system security

strategic bidding in an energy brokerage this focus of this paper is to present a framework in which strategies may developed for the individual participants in an energy brokerage such a framework is expected to be important with the increasing interest in electricity market structures such as the energy brokerage that deregulation has produced to illustrate the process of strategic bidding a simple suboptimal bidding strategy is presented with the aid of a numerical example the bidding strategy must be suboptimal because of the amount of unknown information about the other bidders further tuning of this strategy will be required before application to realistic scenarios

competition and quality in health care markets a differential game approach we investigate the effect of competition on quality in health care markets with regulated prices taking a differential game approach in which quality is a stock variable using a hotelling framework we derive the open loop solution health care providers set the optimal investment plan at the initial period and the feedback closed loop solution providers move investments in response to the dynamics of the states under the closed loop solution competition is more intense in the sense that providers observe quality in each period and base their investment on this information if the marginal provision cost is constant the open loop and closed loop solutions coincide and the results are similar to the ones obtained by static models if the marginal provision cost is increasing investment and quality are lower in the closed loop solution when competition is more intense in this case static models tend to exaggerate the positive effect of competition on quality

pricing flexible electricity contracts this paper is concerned with pricing of electricity contracts that allow flexible scheduling of the supply or demand of electric energy the contracts are priced based on the principle of no arbitrage variables of the contracts are used to determine arbitrage opportunities and the price of contracts pricing of flexible contracts involves a scheduling policy by representing the spot price with an appropriate stochastic process the scheduling policy can be found using stochastic dynamic programming simulation examples illustrate the tradeoffs between prices and scheduling flexibility