provision of electricity to african households the importance of democracy and institutional quality how can differences in per capita household electricity consumption across african countries be understood based on theories that highlight the importance of democracy and institutional quality for provision of public goods the aim of the paper is to analyse the degree to which the level of per capita household electricity consumption in african countries can be attributed to the countries democratic status and their institutional quality we rely on regression analysis employing a pooled data set for 44 african countries over the time period 1996 2009 the analysis shows that democracy and institutional quality both have significant positive effects on per capita household consumption of electricity our results have implications for how energy sector reforms are promoted in developing countries at a more general level they illustrate that institution building policy efforts are relevant also in areas where contemporary debates have tended to primarily centre on economic development financial prerequisites and ownership issues

price response information and asymmetry of price dispersion abstractin this study we examine how differently gasoline prices in 25 regions of seoul korea respond to asymmetric information between retailers and consumers we estimate the region specific li

a model of temporary search market equilibrium abstract in the literature on search markets agents know the distribution of prices or learn about it through short run bayesian updating even though the first assumption is unrealistic and the empirical evidence emphasizes learning in the intermediate and long runs in this paper a new search markets theory is developed where agents have beliefs about the distribution of prices based on finitely many of its moments and past market experiences the main results are the existence of a hicks grandmont temporary equilibrium that the equilibrium correspondence has a closed graph and sufficient conditions for price dispersion a simple example illustrates the main ideas journal of economic literature classification numbers d83 l13

oligopolistic markets with sequential search and production cost uncertainty this article analyzes a sequential search model where firms face identical but stochastic production costs the realizations of which are unknown to consumers we characterize a perfect bayesian equilibrium satisfying a reservation price property and provide a sufficient condition for such an equilibrium to exist we show that i firms set on average higher prices and make larger profits compared to the scenario where consumers observe production costs ii expected prices and consumer welfare can be non monotonic in the number of firms and iii the impact of production cost uncertainty vanishes as the number of firms becomes very large

power market long term stability a hybrid madm ga comprehensive framework stabilizing the long term electricity markets by providing new generation resources is one of the most important challenges that are surfaced to the industry regulators to deal with this complex problem this paper proposes a comprehensive multiple attribute decision making madm framework in which the genetic algorithm ga is used to model the investment decisions of the market generation firms the fitness function of the ga is itself a decentralized optimization problem that simulates the short term behavior of these profit oriented firms a simple fuzzy inference system and an elasticity relation between price and demand represent the power market as the link among all firms the framework is augmented by tradeoff risk analysis to incorporate the effects of the uncertainties finally a realistic case study is presented to show the advantages of the proposed framework

gis and rural electricity planning in uganda abstract sustainable development is literally fuelled by the energy sector in uganda the electricity sector has experienced dramatic market liberation in recent years this reform was centred around the unbundling of the main government utility uganda electricity board ueb a monopoly divided into three companies created to introduce competition into the market market reform has also led to the creation of a regulatory body and a rural electrification fund with the aim of subsidising rural electricity investments through a multi sectoral programme financed by the world bank and the global environment facility gef the ministry of energy is developing a rural electrification master plan to provide a more systematic tool for rural electricity investments unlike previous approaches this plan is demand driven this paper discusses the use of geographic information systems gis in the planning process for rural electrification the aim is to identify patterns of demand and priority areas for investment by creating a demand side scenario electricity can then be supplied to targeted areas a cross sectoral view is taken to examine the energy demand patterns using physical data and available country statistics incorporated into a gis master database based on geo referenced data of population and existing infrastructure the initial priority demand side sectors targeted are education and health an energy benefit point system is then applied to each sector based on local conditions and needs assessments their aggregated points then provide an indicator of energy demand distribution for electricity planning at district level as a result of this preliminary work specific areas could then be targeted for investment and optimised supply systems could be designed which include off grid renewable energy plants such as small scale hydropower schemes

transmission planning criteria and their application under uncertainty planning criteria are the basis of transmission planning these criteria implicitly embody resolve conflicting objectives e g cost vs reliability quantitative methods are used to set criteria by resolving conflicting objectives once criteria are set they must be applied under uncertainty in future demand generation etc transmission plans are evaluated for hundreds of possible futures risk analysis measures robustness exposure and regret non financial hedges can reduce risk these risk concepts have a rich history but are rarely applied in transmission planning developing criteria and applying them under uncertainty are illustrated by a recent planning study for peru

the demand for residential electricity in south africa abstract this paper examines the residential demand for electricity in south africa as a function of real gross domestic product per capita and the price of electricity during the period 1978 2005 we make use of the bounds testing approach to cointegration within an autoregressive distributed framework suggested by pesaran et al 2001 bounds testing approaches to the analysis of level relationships journal of applied econometrics 16 3 289 326 following the literature we use a linear double logarithmic form using income and price as independent variables in the empirical analysis in the long run we find that income is the main determinant of electricity demand while electricity price is insignificant

search with learning understanding asymmetric price adjustments in many retail markets prices rise faster than they fall we develop a model of search with learning to explain this phenomenon of asymmetric price adjustments by extending our static game analysis to the dynamic setting we demonstrate that asymmetric price adjustments arise naturally when a positive cost shock occurs all the searchers immediately learn the true state the search intensity and hence the prices fully adjust in the next period when a negative cost shock occurs it takes longer for nonsearchers to learn the true state and the search intensity increases gradually leading to slow falling of prices

electricity planning and implementation in sub saharan africa a systematic review abstract universal electricity access is an important development objective and the focus of a number of key global un initiatives while robust electricity planning is widely believed to be a prerequisite for effective electrification to date no comprehensive overview of electricity planning research has been undertaken on sub saharan africa the world region with the lowest access rates this paper reviews quantitative and qualitative electricity planning and related implementation research considering each of the 49 sub saharan african countries the four regional power pools and the sub continent as a whole applying a broad understanding of electricity planning and a practical limit of 20 reviewed articles per country and region 306 relevant peer reviewed journal articles are included in this review a general classification scheme is introduced that classifies the planning literature along the addressed value chain depth number of different analysed criteria and number of evaluated decision alternatives the literature is found to be strongly clustered in a few countries with less than 5 identified relevant articles in 36 of the 49 countries the total amount of articles per year is clearly increasing over time addressing technology choice operation distribution and implementation analyses although including different high level criteria in analysing electricity systems is common the literature is only starting to use formalised multi criteria decision making mcdm tools the review indicates that 63 of relevant articles favour renewable energy technologies for their given problems frequently mentioned success factors for electrification in sub saharan africa include adequate policy design sufficient finance and favourable political conditions while considerable regional and methodological literature gaps are apparent the literature in this review identifies a rich and fruitful ground for future research to fill these gaps

future energy development in tanzania the energy costs of urbanization abstract this paper utilizes the detailed energy balance data developed as part of the tanzania urban energy project to examine future energy use in tanzania the energy costs of urbanization are shown to be quite substantial national energy balances demonstrate that the urban areas make up a large share of the consumption of all fuels except woodfuel as urbanization continues into the future it will be accompanied by dramatic increases in the consumption of petroleum fuels electricity and charcoal for example using base case or business as usual assumptions over a planning period stretching from 1990 to 2010 every 1 increase in the level of urbanization can be expected to lead to a 12 increase in electricity consumption a 14 increase in the consumption of all petroleum fuels and a 14 increase in the consumption of charcoal finally the paper examines different energy policy options which are consistent with the stated national energy policy after the examination of a set of ambitious policy efforts a set of feasible policies are tested and shown to have a significant impact on the goals of improving efficiency obtaining the desirable energy consumption profile and conserving indigenous woodfuel resources

non reservation price equilibria and consumer search abstract reservation price equilibria rpe do not accurately assess market power in consumer search markets in most search markets consumers do not know important elements of the environment in which they search such as for example firms cost we argue that when consumers learn when searching rpe suffer from theoretical issues such as non existence and critical dependence on specific out of equilibrium beliefs we characterize equilibria where consumers rationally choose search strategies that are not characterized by a reservation price non rpe always exist and do not depend on specific out of equilibrium beliefs non rpe have active consumer search and are consistent with recent empirical findings

powering africa s sustainable development the potential role of nuclear energy abstract the electricity deficit is one of the most serious contemporary issues facing sub saharan africa many countries in the region have insufficient generation capacity to meet rapidly rising demand electricity shortages have become a binding and powerful constraint on the continent s sustainable development their resolution will require coordinated effort to improve the effectiveness and governance of the region s utilities and to significantly scale up generation capacity a broad portfolio of low carbon low c technologies needs to be deployed in order to address the electricity deficit in a cost effective way and not be disruptive to economic growth since nuclear power can deliver low c electricity in bulk reliably and without intermittency it could make a significant contribution towards resolving africa s power crisis however the post fukushima safety concerns related to large nuclear plants with substantial radioactive inventories will be especially pronounced in africa moreover large scale reactors with huge upfront investment requirements are likely to be unsuitable for capital constrained african countries with small electricity grids one promising direction for nuclear development in africa might be to downsize reactors from the gigawatt scale to less complex smaller units with substantially smaller radioactive inventory that are more affordable

powering africa meeting the financing and reform challenges africa faces chronic power problems including insufficient generation capacity low connectivity poor reliability and high costs all of which constrain development power capacity additions in sub saharan africa excl sa since the 1990 s were minuscule historically investments in the power sector in africa have come mostly from governments or public utilities with foreign aid support in recent years these sources of funding have been flat the fastest new sources of funding are from independent power producers ipps and from china to understand the determinant of the new sources the paper analyses the effect of several key factor and find non expected results such as there is no obvious correlation between unbundling or the presence of an independent regulator and the level of private investment through ipps or that there is no correlation between chinese investment in generation and resource rich countries dispelling the myth that chinese firms are only interested in africa s resources the paper delivers several recommendations that indicate that more attention needs to be given to issues related to planning procurement and contracting as well as securing revenue flows jel classification o13 o25 l94

pensions and wages an hedonic price theory approach this paper examines whether a trade off exists between the level of pension benefits and wages the 1983 survey of consumer finance is used to match detailed information on pension plans to worker characteristics for a random sample of the population the pension wage tradeoff is estimated using both a contractual model of the labor market and the spot market model used in previous studies the results indicate a large negative tradeoff in the contractual model but only a negligible tradeoff in the spot market model results from estimating the underlying structural equations for pensions are also presented copyright 1992 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

urban household energy use in tanzania prices substitutes and poverty abstract this paper presents the findings of the tanzanian urban household energy survey undertaken as part of the tanzania urban energy project household energy use varies by income group according to local fuel availability considerable differences between the marginal costs of supplying fuels and market prices paid by consumers have led to major misallocations of resources when the results of this survey are compared to the results of the 1987 household energy survey a significant shift by households toward kerosene and electricity away from fuelwood charcoal and lpg is shown to have taken place these shifts toward modern fuels are consistent with the claims of the households in the 1990 survey and can largely be explained by fuel prices finally an assessment of the lifeline tariff and the kerosene cross subsidy demonstrate that the latter is a more effective method of ensuring the basic energy needs of the urban and rural poor

establishing the role that wind generation may have in future generation portfolios assessing the correct future mix in generation portfolios has become more difficult given the introduction of emission trading schemes the recent fuel price rises and the increasing competitiveness of wind energy this paper combines analysis of generation economics load and wind generation characteristics generation adequacy and plant utilization to gain insight into the role of wind generation in desirable generation portfolios the unique characteristics of wind generation are accounted for in the analysis and sensitivity analysis is carried out with respect to discount rates carbon taxes and various fuel price scenarios results show that for a large range of future scenarios wind generation has a significant role to play in future generation portfolios in ireland mean variance portfolio theory is applied to examine the benefits of portfolio diversification in terms of avoiding exposure to volatile fuel prices analysis shows that wind generation has a further role to play in generation portfolios in this respect

job queues and the union status of workers this paper develops a model of the determination of the union status of workers that allows for the possibility of queuing for union jobs the empirical results derived using a sample from the university of michigan panel study of income dynamics are supportive of the queuing hypothesis the no queue model can be rejected using a likelihood ratio test this suggests that a simple probit or logit model for union status is misspecified because it is not based on any consistent behavioral theory an important implication of the model is that because most new entrants to the labor market prefer union jobs but cannot get them and because accrual of nonunion seniority makes workers progressively less likely to desire union jobs the union status of workers is largely determined by their success in being selected from the queue early in their working life

search with learning and price adjustment dynamics we present a model of consumer search with learning in which cost shocks have different short and long range effects on prices in the short run consumers confuse general cost shocks common to all firms in the industry with firm specific shocks in the case of a general cost increase this promotes an excessive propensity to search restraining the amount by which prices increase in the short run conversely in the case of an idiosyncratic cost increase consumers search too little causing the prices of high cost firms to overshoot

deregulation privatization and competition transmission planning under uncertainty competitive markets expose transmission planners to new uncertainties these are handled using a decision analysis approach whose key contribution is quantifying and minimizing risk the method is applied using existing and generally available software tools the result is transmission plan which is robust in the face of uncertainties a study of a major proposed central american interconnection illustrates the problem and the method

solar energy applications and development in nigeria drivers and barriers abstract in this study current perspectives of solar energy utilization as a renewable energy option in nigeria are examined and discussed from the standpoint of sustainable development the country being a world crude oil and natural gas producer is over dependent on these energy sources for electricity generation and other energy applications this has currently put the country at a risk of impending energy crises in view of the fast diminishing fossil reserves inadequate refining capacity to meet domestic consumption and serious cases of energy insecurity in restive regions where exploitations exist in spite of the vast fossil based energy reserves a meager electricity production capacity that is put at 4517 6 mw as at december 2012 is generated to support the economy of a teeming population of approximately 170 million people nigeria is naturally endowed with abundant deposit of renewable energy resources of which solar energy from the sun being the world s most abundant and permanent energy source has for decades been enjoying very high level utilization by rural dwellers for agricultural processings in the country it is vastly deposited with an estimated 17 459 215 2 million mj day of solar energy falling on the country s 923 768 km2 land area approximate range of 12 6 mj m2 day in the coastal region to about 25 2 mj m2 day in the far north the different applications to which solar resources have been put and the extent of utilization including details of existing projects in the country were thoroughly investigated and discussed the possible motivations for extensive development of solar energy conversion systems in nigeria are also discussed and some of the barriers and challenges are presented steps and policy measures to overcome the barriers and facilitates the utilization of this resource are suggested

two stage robust generation expansion planning a mixed integer linear programming model this paper presents a new uncertainty handling framework for optimal generation expansion planning gep amalgamating the notions of single stage and two stage robust optimization ro the proposed multiyear robust gep methodology as a tractable mixed integer linear programming optimization problem copes with the inherent planning uncertainties associated with forecasted electricity load demand as well as estimated investment and operation costs through distribution free bounded intervals producing polyhedral uncertainty sets the optimal generation expansion plan obtained from the proposed ro approach is immunized against worst case planning uncertainties considering the adopted degree of conservatism for each uncertainty set therefore the proposed methodology is capable of controlling the robustness of the optimal investment schedule regarding the enforced planning uncertainties simulation results demonstrate the efficacy and efficiency of the proposed ro framework throughout gep studies

the economics of planning electricity transmission to accommodate renewables using two stage optimisation to evaluate flexibility and the cost of disregarding uncertainty abstract aggressive development of renewable electricity sources will require significant expansions in transmission infrastructure we present a stochastic two stage optimisation model that captures the multistage nature of transmission planning under uncertainty and use it to evaluate interregional grid reinforcements in great britain gb in our model a proactive transmission planner makes investment decisions in two time periods each time followed by a market response uncertainty is represented by economic technology and regulatory scenarios and first stage investments must be made before it is known which scenario will occur the model allows us to identify expected cost minimising first stage investments as well as estimate the value of information the cost of ignoring uncertainty and the value of flexibility our results show that ignoring risk in planning transmission for renewables has quantifiable economic consequences and that considering uncertainty can yield decisions that have lower expected costs than traditional deterministic planning methods in the gb case the value of information and cost of disregarding uncertainty in transmission planning were of the same order of magnitude approximately 100 m in present worth terms further the best plan under a risk neutral decision criterion can differ from the best under risk aversion finally a traditional sensitivity analysis based robustness analysis also yields different results than the stochastic model although the former s expected cost is not much higher

transforming the nigerian power sector for sustainable development abstract nigeria has been plagued with acute power shortages due to poor performance of its power sector several policies and reforms have been implemented by the government to address the poor performance of the power generation transmission and distribution sectors of the electricity industry also various strategies were employed by the government which includes encouraging private sector participation diversification of the energy generation sources and promoting energy efficiency for sustainable development in addition the government has spent billions of dollars since 2001 in the construction of new power generation facilities transmission lines and distribution centers to boost the power supply it has deregulated the generation and distribution sectors to encourage private sector participation and empowers the energy commission of nigeria to embark on programs and strategies that can boost energy generation from renewable sources this paper examined the country s energy sources and the power sector reforms adopted by the government the paper also outlined some recommendations based on reforms implemented by other countries with similar resources to nigeria which yielded positive results

power sector reforms in zimbabwe will reforms increase electrification and strengthen local participation abstract zimbabwe is a developing country currently in the grips of an economic crisis the power sector has been starved of investments and there is an inadequate revenue flow into the country to finance new investment internal resources are inadequate to maintain the current system and to finance new investment financial and operational performance has deteriorated rural electrification is very low with only 18 of the population having access to electricity the government and the utility zimbabwe electricity supply authority have recognised their inability to meet these challenges and have initiated a reform program in order to open up the power sector to private investors this article analyses the current technical and operational problems faced by the utility and their impact on its financial performance in addition the article reviews the status of electrification in zimbabwe and the participation of local private investors in the power sector policy recommendations on how the technical and financial performance of the utility can be enhanced and on how the rate of electrification especially in rural areas can be improved are presented the increased participation of local private sector players into the power industry is a key issue and recommendations are made on how the government can provide incentives to facilitate their effective participation

reassessing the energy ladder household energy use in maun botswana abstract in the context of sub saharan africa s rapid urbanization improved insight into urban energy use is increasingly important based on the predictions of energy transition theory a regional shift from biomass to modern fuels has long been expected to occur in tandem with urban growth however trends observed in the region s towns and cities have often not followed such patterns and fuelwood continues to be important in most areas this paper examines the practical relevance of transition theory using a recent case study conducted by the authors in maun botswana and results previously reported in the literature it finds that despite the long term link between socio economic development and increased modern fuel consumption at the national scale the notion of transition does not accurately reflect ongoing energy use patterns at lower levels of aggregation this is chiefly because its model of household fuel switching largely dismisses the importance of active and strategic decision making by urban consumers and their responsiveness to structural factors such as relative fuel prices as the botswana case illustrates this weakness can significantly distort expectations and policies around urban fuelwood use

conflicting objectives and risk in power system planning planning in the 1990s must deal with a wide range of options with conflicting objectives and with uncertainty types of conflict among planning objectives are illustrated and categorized risk is distinguished from uncertainty and both are qualified hedging to reduce risk is demonstrated real examples are drawn from major recent planning studies

tariffs and subsidies in zimbabwe s reforming electricity industry steering a utility through turbulent times abstract in 1991 the government of zimbabwe adopted a public enterprise reform strategy as part of a world bank driven economic structural adjustment programme esap for the electricity sector the government adopted a two pronged programme of reform a performance improvement programme pip for the national utility the zimbabwe electricity supply authority zesa and a legal and regulatory reform programme for the electricity sector in general ten years later significant success has been achieved in improving the utility s performance in technical operations and customer service however there has been very little progress on the legal and regulatory front this has adversely affected the utility s financial performance as well as frustrating the government s efforts in attracting private sector investment the centrality of the tariff question reflects the importance of the customer or end user to the power sector reform process this article outlines the power sector reform experiences in zimbabwe with special focus on the tariff question the paper suggests from the perspective of a utility executive reasons for the mixed results at zesa and lessons for other countries in the region undertaking similar reforms

household energy demand in kenya an application of the linear approximate almost ideal demand system la aids abstract this paper estimates price and fuel expenditure elasticities of demand by applying the linear approximate almost ideal demand system la aids to 3665 households sampled across kenya in 2009 the results indicate that motor spirit premium msp automotive gas oil ago and lubricants are price elastic while fuel wood kerosene charcoal liquefied petroleum gas lpg and electricity are price inelastic kerosene is income elastic while fuel wood charcoal lpg electricity msp and ago are income inelastic the results also reveal fuel stack behaviour that is multiple fuel use among the households main policy implications of the results include increasing the penetration of alternative fuels as well as provision of more fiscal incentives to increase usage of cleaner fuels this not withstanding however the household income should be increased beyond a certain point for the household to completely shift and use a new fuel

unemployment insurance job queues and systematic job search an equilibrium approach the labor market effects of unemployment insurance ui have been viewed in several contexts by economists on the one hand the ui system of jobless benefits and experiencerated taxation of firms is seen as influencing firms decisions to lay off workers 9 10 24 2 key in such analyses is the degree to which firms layoffs are subsidized by an imperfect experience rating a tax system in which employers ui taxes increase by less than their workers benefits increase on the other hand many other studies of ui place primary focus on the worker although employer concern for worker well being plays a role even in the work on the impact of ui on firm layoff decisions each of these worker based studies is concerned with one of two issues 1 ui and compensating wage differentials 14 24 or 2 u i and the job search process first hutchens assumes that workers face a choice in the labor market between high wage high layoff probability firms and low wage low layoff probability firms 14 by reducing the cost of being laid off ui increases one s likelihood of choosing the former kind of job along these lines topel finds evidence that ui generosity substitutes for wages and therefore lowers the compensating differential associated with a high layoff job 23 second several authors have studied the effect of ui on job search this work recognizes that ui lowers the cost of searching and therefore raises the reservation wage expected unemployment duration and expected post unemployment wages 2 previous work on the impact of ui on firm layoff decisions has assumed either a layoff subsidy 9 or demand uncertainty 2 in order to generate layoffs and therefore a u i impact on layoffs in contrast to such work this paper views layoffs in an equilibrium context they occur in our model even with no layoff subsidy and or with no demand uncertainty layoffs are of value to the firm in our model since they correspond to workers rejected from a queue of potential trainees from the firm s point of view a queue of applicants may be desirable in order to lower

adam smith may have been right after all a new approach to the analysis of compensating differentials abstract if workers with low wages compared to their level of human capital exaggerate their workplace disamenities estimates of compensating differentials will be biased evidence of such a bias is found in a matched employee employer survey

compensating wage differentials and the duration of wage loss a formal model of occupational choice is developed that shows the extent to which the compensation for increased duration exceeds that for increased risk using the panel study of income dynamics linked to industry data on injuries and unemployment we find nearly all the compensating wage differential for losses due to workplace injuries is for increases in the duration of loss and similarly for losses due to cyclical unemployment the compensating differentials for risk of injury are larger for union than for nonunion workers while those for cyclical unemployment are smaller for union workers

avoiding academic and decorative planning in ghg emissions abatement studies with mcda the peruvian case abstract climate change issues have been considered some of the most complex and messy situations which the decision sciences face in the last decade many countries have carried out studies related to climate change mitigation the relevance of the outcomes of such studies depends on how well technical analysis the priorities of the decision makers and technical political feasibility are integrated this paper focuses on a framework suggested by the united nations environmental programme unep to study the costs and impacts of national policies for abating greenhouse gases ghg emissions it illustrates how the quest for the inclusion of mcda assessment in national greenhouse abatement costing studies can without departing from the established analysis framework be a pretext to provide a process which enhances stakeholder participation validation and ownership of the planning process such a process was used in a national study in peru

consumer search and double marginalization the well known double marginalization problem understates the inefficiencies arising from vertical relations in consumer search markets where consumers are uninformed about the wholesale prices charged by manufacturers to retailers consumer search provides a monopoly manufacturer with an additional incentive to increase its price worsening the double marginalization problem and lowering the manufacturer s profits nevertheless manufacturers in more competitive wholesale markets may not have an incentive to reveal their prices to consumers we show that retail prices decrease in search cost and so both industry profits and consumer surplus increase in search cost jel d11 d42 d83 l12 l25 l60 l81 in markets where consumers do not know retail prices and need to invest time and resources to get to know them they often also do not know retailers marginal costs even though consumers are not directly interested in retailers costs these costs are indicative for whether consumers should buy at the current shop or continue to search for the next offer this is particularly true when there is a significant common component in retailers costs for the same observed price at a particular retailer if the common cost is low the retailer s margin is high and it is more beneficial to check the price at the next retailer as he is likely to maintain a lower margin and hence to charge a lower price this paper studies consumer search in markets where retailers have a common marginal cost that is set by a manufacturer as a reference point we consider the unrealistic case where consumers are fully informed about the wholesale price that retailers must pay the manufacturer and show how the familiar double marginalization problem arises we then consider the more realistic setting where consumers

modelling electricity demand in ghana revisited the role of policy regime changes as policy regime changes demand elasticities are unlikely to be constant since individuals change how they form their expectations and this will change the estimated decision rules in this paper the time varying nature of electricity demand elasticities prior to and post the economic reform period in ghana is analysed using the fm ols three different sample periods pre reform post reform and full period was used in the analysis the result from the full sample period revealed that in the long run electricity demand is significantly affected by industry efficiency industry value added and real per capita gdp urbanization rate however has no significant effect the pre reform estimate showed lower income output and urbanization elasticities but higher industry energy efficiency elasticity relative to the post reform period this suggests that technological change in the pre reform period has been energy saving whilst technological change in the post reform period has been energy consuming the result further showed evidence of changing structure of the economy from the more energy intensive sector to the less energy intensive sector after the reform government should renew her effort in promoting energy saving technologies in the industrial sector and adjust the industrial structure to encourage the expansion of low energy intensive industries or high technology efficient industries

adaptation of feed in tariff for remote mini grids tanzania as an illustrative case abstract following the successful feed in tariffs fits system worldwide few countries have implemented fits explicitly tailored for off grid or mini grid systems this study takes an integrated approach to examine the feasibility of an off grid feed in tariff off fit for existing and new remote mini grids in tanzania using a combination of geographical analysis technical economic and institutional assessments based on detailed modelling of two community off grid cases i pv diesel and ii mini hydro we identify least cost rural electrification options that make solar and mini hydro energy competitive with diesel generators and potential effect of the support scheme on rural electrification plans in the first case we illustrate where the off fit complements diesel generation of an existing mini grid pv diesel in the second case mini hydro we illustrate conditions where the off fit policy brings mini hydro generation to non electrified communities and sells renewable electricity directly to new customers currently tanzania has standardized power purchase spp rates which target generators connected to the national grid and distribution systems of mini grids or isolated grids we found for the off fit tariff the total amount needed to support the same number of customers by solar and hydro mini grids versus diesel would be of 31 5 million us or a premium of 0 11 us kwh to the present current spps tariff of 0 24 us kwh for pv we also found that a technology specific fit tariff would be most suitable to attract national and international investors by providing a rate of return that compensates the risk of the investment the overall support is comparable to the 36 million us that the government currently subsidizes and allocates to diesel mini grids in country and this shows the potential for a long term renewable energy strategy for mini grid areas

comparable assessment of national ghg abatement costs this paper discusses the unep greenhouse gas abatement costing project with particular emphasis on the national assessments of co2 abatement cost for developing countries a methodological framework was developed and country studies were conducted for 10 countries national marginal abatement cost curves for the short term 25 reduction from baseline by 2005 to 2010 and long term 50 reduction from baseline by 2020 to 2030 targets are presented and discussed the cost curves for the selected countries exhibit a number of similarities the paper examines critically how the main scenario assumptions about energy gdp intensity and energy efficiency improvement influence the assessed abatement potential and costs the treatment of no regrets options in the baseline and abatement cases is discussed in relation to a developing country planning context the issue of comparability between assessments from different countries is addressed even with uniform assumptions discount rates oil prices etc for the group of countries as a whole comparability within the unep project is shown to be a complex concept which involves national differences in the projection of economic and energy system development and the use of different modelling approaches

community based electric micro grids can contribute to rural development evidence from kenya summary in this paper we clarify the mechanisms through which rural electrification can contribute to rural development through a detailed case study analysis of a community based electric micro grid in rural kenya we demonstrate that access to electricity enables the use of electric equipment and tools by small and micro enterprises resulting in significant improvement in productivity per worker 100 200 depending on the task at hand and in a corresponding growth in income levels in the order of 20 70 depending on the product made access to electricity simultaneously enables and improves the delivery of social and business services from a wide range of village level infrastructure e g schools markets and water pumps while improving the productivity of agricultural activities we find that increased productivity and growth in revenues within the context of better delivery of social and business support services contribute to achieving higher social and economic benefits for rural communities we also demonstrate that when local electricity users have an ability to charge and enforce cost reflective tariffs and when electricity consumption is closely linked to productive uses that generate incomes cost recovery is feasible 2008 elsevier ltd all rights reserved

power sector renewable energy integration for expanding access to electricity in sub saharan africa abstract a looming energy supply crisis in sub saharan africa ssa raises concerns about a long lasting energy shortage this energy crisis is expected to persist for an indefinite period in the region unless immediate actions are taken to reverse the trend although global aspiration to reduce greenhouse gas ghg emissions into the atmosphere is high such desire is low in ssa regional stakeholders are more worried about increasing power generation capacity to enhance better access to different sorts of development to progress in line with advanced patterns of energy development globally to increase the availability of electrical energy and to sustain emissions reductions exploitation of local renewable energy re resources is inevitable consequently this paper presents a comprehensive review of re integration for expanding access to electricity in ssa the review covers the sustainability of re resources in ssa the regional status of re applications and the necessity of re power generation integration planning from a management aspect finally the benefits of re integration into the power sector of ssa and some conceptual challenges affecting its integration in the region are highlighted

the cost of providing electricity to africa abstract sub saharan africa lacks electricity we estimate the cost of providing electricity to the region to do so we build an optimisation model that links the electricity demand to the supply and links the supply to the generation distribution and transmission of electricity between countries to the best of our knowledge such a model is novel in the literature we determine that the investment cost of providing electricity to sub saharan africa over a 10 year period is between 160 and 215 billion u s dollars depending on assumptions for electricity access and the cross country electricity trade although the electricity trade increases the investment cost estimate moderately it provides a high return to african countries and is cost efficient overall

nigeria s electric power sector reform what should form the key objectives nigeria s electric power sector requires substantial reform if the country s economic development and poverty alleviation program is to be realised this understanding is behind the reform programme recently initiated by the nigerian government with the goal of privatising the national electric power monopoly nepa currently the country faces serious energy crisis due to declining electricity generation from domestic power plants which are basically dilapidated obsolete unreliable and in an appalling state of disrepair reflecting the poor maintenance culture in the country and gross inefficiency of the public utility provider building on an analysis of the major shortcomings of the current electric power company this paper presents the central issues that should form the key objectives of the proposed reform this include corporatization of the electric power industry increasing access and power delivery capacity constraining the costs of the power industry and increasing efficiency and share of renewables in energy generation as well as minimising environmental damage we conclude with the observation that efforts at reform will not yield the desired result if the current end user inefficiency is not constrained as nigeria implements its national utility privatisation programme it is hoped that this review will benefit policy makers and emerging managers and providers of electricity service in the country

extensive search intensive search and hiring costs new evidence on employer hiring activity this paper presents recent evidence on employer search to fill a position a 1982 employer survey sponsored by the national institute of education and the national center for research in vocational education provides the basis for analyzing employer search and hiring costs the paper examines the effects of such factors as employer size dismissal costs unionization on the job training adjustment costs capital and labor market conditions on intensive employer search extensive employer search and hiring costs intensive employer search is measured by the average number of hours the employer spends recruiting screening and interviewing per applicant extensive search is measured by the number of applicants seen per applicant interviewed and the number interviewed per employment

business as usual a consumer search theory of sticky prices and asymmetric price adjustment abstract empirical evidence suggests that prices are sticky with respect to cost changes moreover prices respond more rapidly to cost increases than to cost decreases we develop a search theoretic model which is consistent with this evidence and allows for additional testable predictions our results are based on the assumption that buyers do not observe the sellers costs but know that cost changes are positively correlated across sellers in equilibrium a change in price is likely to induce consumer search which explains sticky prices moreover the signal conveyed by a price decrease is different from the signal conveyed by a price increase which explains asymmetry in price adjustment

re thinking the power transmission model for sub saharan africa abstract a vision for a united states of africa has been advocated since the dawn of independence by among others pioneers like kwame nkrumah gamal abdel nasser and julius nyerere more recently the idea gained new momentum through such initiatives as the new partnership for african development nepad and the african union au to create a single market of africa s 750 million people that is competitive within itself and within the global economy this would be achieved through a deliberate systematic and concerted effort to integrate upgrade and modernize infrastructure that would offer the required catalyst for economic growth however the prioritization by african policy makers of a grand plan to link up the entire african continent s electric power grid networks would appear to be incompatible with 21st century thinking the specifications for a centrally managed power grid were made by nicola tesla in 1883 and have served the power industry for over 125 years but are now obsolete in the era of digital micro electronics and smart grid concepts this paper examines some issues that surround the evolution of sub sahara african regional power pools and highlights the anomalies and perhaps wrong timing around the conceptualization and prioritization of grand inter state power grids the authors then propose an alternative model that conforms to a new and more sustainable paradigm in electricity supply economics the proposals are however not meant to provide a panacea but it is hoped that the article will ignite a debate that will lead to a lasting solution

use of multicriteria decision analysis methods for energy planning problems most decision making requires the consideration of several conflicting objectives the term multiple criteria decision analysis mcda describes various methods developed for aiding decision makers in reaching better decisions energy planning problems are complex problems with multiple decision makers and multiple criteria therefore these problems are quite suited to the use of mcda a multitude of mcda methods exists these methods can be divided in three main groups value measurement models goal aspiration and reference level models and outranking models methods from all of these groups have been applied to energy planning problems particularly in the evaluation of alternative electricity supply strategies each of the methods has its advantages and drawbacks however we cannot conclude that one method generally is better suited than the others for energy planning problems a good alternative might be to apply more than one method either in combination to make use of the strengths of both methods or in parallel to get a broader decision basis for the decision maker until now studies of mcda in energy planning have most often considered energy networks with only one energy carrier more advanced energy systems with multiple energy carriers have been neglected even though this field ought to be suitable for use of mcda due to its high complexity many decision makers and many conflicting criteria

demand for energy in rural and urban centres of ethiopia an econometric analysis the paper starts by briefly discussing the current energy situation in ethiopia the major source of energy in ethiopia is traditional and the major consumer is the household a simple model of household utility function where energy consumption is the major variable is developed and a reduced form is derived to make the model operational a simultaneous equation system describing the demand for and supply of traditional and modern energy sources has been specified the model is closed by equating the demand for energy with the supply data from the national energy survey were used to estimate the model the major finding of the study is that price of traditional energy plays an important role in the consumption of fuelwood and other traditional energy sources by manipulating the price variable the government may be ale to control the high rate of depletion offorest resources

energy sector reform in eritrea initiatives and implications abstract the government of eritrea gave priority status to the energy sector immediately after the country s independence in may 1991 as manifested by the rapid improvement in electricity and oil supplies electricity generation capacity has increased from a total of 30 mw in 1991 to over 130 mw at present the lengths of transmission and distribution lines have similarly increased from 150 km to 400 km and from 800 to 1300 km respectively however as in most sub saharan africa this public utility is characterised by inefficient managerial technical and financial performances an inability to mobilize the funds needed for expansion low repair and maintenance capacity inappropriate tariff rates and inadequate revenue collection mechanisms this has led the government to take appropriate reform measures in recent years including the restructuring of the eritrea electric corporation eec to operate on commercial principles setting tariffs based on real costs and reasonable profits effective collection of revenues the minimization of wastage and loss in the delivery of energy services facilitating the private sector participation and ring fencing the interests of the poor by setting up a rural electrification fund a regulatory body has been established to enforce these reform measures recognising the role of modern energy in poverty reduction and achieving the millennium development goals mdgs the government with the support of its development partners is expanding energy services to rural areas in an innovative manner the government s commitment to diversify energy sources is exemplified by its agreement with the global environment facility gef to share the costs of an on going pilot wind energy project it has also established an energy research and training centre to promote the application of renewable energies and improved biomass stoves throughout eritrea

eliciting gps preferences for pecuniary and non pecuniary job characteristics abstract this study examines general practitioners preferences for pecuniary and non pecuniary job characteristics in the context of choosing a general practice in which to work a discrete choice experiment is used to test hypotheses about the nature of the utility function marginal rates of substitution between income and non pecuniary characteristics are calculated the results suggest that policies aimed at influencing general practitioners location choices should take account of both non pecuniary and pecuniary factors particularly out of hours work commitments

energy services in sub saharan africa how conducive is the environment the bulk of rural populations in sub saharan africa have no access to electricity and are under served by any other form of modern infrastructure the cost of infrastructure to mainly scattered communities has been perennially cited as largely to blame this is an undeniable truth but only part of it there are in addition myriads of social economic and political obstacles that play an unquantified and frequently unrecognized negative role at the route of the problem lies a subdued role of the would be recipients who in fact unlike anybody else are conversant with their problems consequently a number of products may come as impositions or misplaced priorities consumer participation for sustainable development has been articulated at international forums and in publications as being advantageous in practice however the concept appears to be generally shunned and even when occasionally tried the needs of the consumers are presumed and their roles prescribed this paper discusses a range of social economic and political issues that constitute major obstacles to the realisation of sustainable rural development

how sustainable is policy incoherence a rationalist policy analysis of the cameroonian electricity reform abstract instead of being the milestone in cameroon s economic reform program that the international finance corporation ifc claimed it would be the 2001 privatisation of the cameroonian electricity sector has turned out to be a millstone round the government and country s neck this paper documents and analyses the multidimensional incoherence embedded in the cameroonian electricity sector reforms initiated under the pressure of structural adjustment credit projects led by the world bank more specifically 12 policy incoherencies are examined in the cameroonian context they range from a poor understanding of the electricity sector s problems to pre determined solutions and important shortcomings in the assessment of possible impacts the results of these policy inconsistencies are analysed in terms the sector s sustainability based upon the five key concepts introduced by bruntland suggesting that the reforms have failed to promote social environmental or economic sustainability although this study concerns cameroon its relevance goes beyond this specific country as similar policies are being implemented around the world

unemployment insurance and the business cycle what adjustments are needed author affiliation jeremy schwartz loyola university maryland department of economics 4501 north charles street sellinger 315 baltimore md 21210 usa e mail jsschwartz1 loyola edu acknowledgment i wish to thank donald parsons kerry richmond tara sinclair roberto samaniego and anthony yezer for their helpful comments and discussions regarding this article 1 introductionin most developed countries unemployment insurance ui is a static program that remains constant regardless of labor market conditions the united states along with canada are the only oecd countries that routinely adjust the generosity of their ui programs with the business cycle for instance during the 2007 2011 labor market downturn the length of time that ui benefits could be collected in the united states increased to an unprecedented 99 weeks from the standard 26 weeks available under normal economic conditions and the weekly benefit amount increased by 25 from an insurance perspective losing one s job during a recession is a greater loss than during an expansion and consequently a greater benefit may be appropriate however it is also known that increasing ui generosity has a negative effect on job search intensity and puts upward pressure on wages leading to lower job creation given these benefits and costs i seek to answer the following questions what structure of benefits over the business cycle is welfare maximizing is the current policy of increasing the generosity of ui during recessions optimal to accomplish this i develop a dynamic search model of the u s labor market which connects two parts of the optimal ui literature the first takes a partial equilibrium approach to determine the optimal adjustments to ui when job finding rates fall but does not consider ui s impact on job creation the second endogenizes job creation but does not address how the benefit system should adjust with the business cycle the model i present is unique in that it allows for both similar to studies that use the partial equilibrium approach one of the main factors driving the optimal ui program in this article is the moral hazard problem that arises from the inability to monitor the unemployed s job search shavell and weiss s 1979 seminal work shows that a sequence of ui benefits that declines with the length of unemployment provides the necessary incentives to encourage job search when the government s objective is to maximize welfare subject to a fixed budget although not explicitly modeling firm behavior hansen and imrohoroglu 1992 allow the ui budget to be endogenously determined similar to this article the authors also frame the moral hazard problem in terms of the government s inability to monitor rejections of job offers as well as allow for private savings they find that the optimal replacement rate is quite low just 0 15 in their baseline moral hazard case hopenhayn and nicolini 1997 focus on unobservable search intensity and develop a widely used recursive contract approach to determine the cost minimizing ui benefit schedule and employment tax where the policy parameters are contingent on an individual s complete work history a benefit amount that declines during one s unemployment spell and a subsequent employment tax that increases with the length of unemployment is optimal and results in utility falling continuously during unemployment pavoni 2007 extends this approach by including a guaranteed lower bound on utility which results in an optimal benefit schedule that falls sharply and includes a one time drop in benefits to a subsistence level alvarez parra and sanchez 2009 explicitly model this lower bound by including a hidden labor market where workers can continue to receive ui benefits undetected in this study the optimal benefit schedule falls slowly at first to ensure workers search in the formal sector and then falls sharply to zero allowing workers to derive consumption from the informal sector

the craft of labormetrics using a wide array of examples from the literature and from original estimates the author examines the pitfalls that make good empirical research in labor economics at least as much craft as statistical technique among the subjects discussed are the appropriateness and cleanliness of data problems of extreme observations the validity of attempts to produce exogeneity using instrumental variables natural experiments and structural models and the treatment of selectivity and unobservable individual effects the author stresses the importance of testing empirical results to ensure that they make sense and of presenting them clearly and economically

the effects of rural electrification on employment new evidence from south africa this paper estimates the impact of electrification on employment growth by analyzing south africa s mass roll out of electricity to rural households using several new data sources and two different identification strategies an instrumental variables strategy and a fixed effects approach i find that electrification significantly raises female employment within five years this new infrastructure appears to increase hours of work for men and women while reducing female wages and increasing male earnings several pieces of evidence suggest that household electrification raises employment by releasing women from home production and enabling microenterprises migration behavior may also be affected jel h54 l94

institutional barriers to a perfect policy a case study of the senegalese rural electrification plan abstract this paper investigates the political and institutional factors that have influenced the success of the senegalese rural electrification action plan plan d action senegalais d electrification rurale paser paser is of interest because its innovative design attracted extensive offers of finance from donors and independent power providers however it has had limited effect on electrification levels this paper examines paser s progress and problems in detail with the aim of informing rural electrification policy internationally an extensive literature review was combined with 26 semi structured stakeholder interviews to produce a snapshot of the plan s status after its first decade of operation paser s experiences are compared with other reform based rural electrification initiatives across sub saharan africa paser has faced significant institutional and political barriers with delays arising from organisational opposition inconsistent ministerial support protracted consultations and the inherent challenges of implementing an innovative policy framework in a country with limited institutional capacity the development of human and institutional capacity has been compromised by inconsistent political commitment such experiences mirror those of electrification initiatives across sub saharan africa whilst paser s successes in garnering external support and fundraising are noteworthy and won praise from early reviews in terms of delivery the plan has failed to resolve common institutional barriers

multicriteria methods for resource planning an experimental comparison multicriteria decision making mcdm methods are widely used for comparing alternatives when there are multiple objectives for instance utilities use them for resource bidding externality quantification facility siting and resource planning there are many alternative methods differing in their ease of use validity results and appropriateness to resource planning several mcdm methods are compared in an experiment involving the choice of resource portfolio for seattle city light planners and interest group representatives applied direct weight assessment tradeoff weight assessment additive value functions and goal programming most of the participants concluded that mcdm methods could promote insight and confidence in decision making however the authors also confirmed the existence of method biases previously identified by psychologists no single method emerged as best thus application of two or more methods as consistency checks is recommended to guard against bias and to stimulate insight

price response asymmetric information and competition we compare predictions from a theoretical model based on the structure of the main outdoor retail market in jerusalem with the results of an empirical analysis of price response to changes in cost we find that firms without adjacent competition exhibit both upward and downward price rigidity an outcome we ascribe to asymmetric information between the consumer and the firm given that previous studies have focused on downward price rigidities of firms with market power our findings highlight the importance of accounting for transitory information asymmetries between the consumer and the firm when studying price rigidity

a new strategy for transmission expansion in competitive electricity markets it will be important to develop a transmission network capable of handling future generation and load patterns in a deregulated unbundled and competitive electricity market a new strategy for transmission expansion under a competitive market environment is therefore presented in this paper in the proposed strategy a new transmission planning model is developed to consider a variety of market driven power flow patterns while a decision analysis scheme is incorporated to minimize the risk of the selected plan numerical examples are given to illustrate the potential of the proposed strategy to make a significant contribution to transmission planning in competitive markets

an empirical model of employed search unemployed search and nonsearch the 1969 1971 national longitudinal surveys data on young men were used to study the employed worker s choice among employed search unemployed search and not searching for a new job we assume that an unobserved variable search intensity governs this choice such that unemployed search involves a greater intensity than employed search which of course is associated with greater intensity than nonsearch the principal results are that current wages seniority collective bargaining coverage employment outside construction and employment by government are each ceteris paribus negatively associated with search intensity further each of these variables lowers the probability of not searching and raises the probabilities of employed and unemployed job search

can small menu costs explain sticky prices abstract we develop a model in which even very small adjustment costs can lead to substantive price rigidity we show that facing a cost increasing shock if firms expect competitors to keep prices unchanged price rigidity may be a self fulfilling prophesy

renewable energy technologies as beacon of cleaner production a real options valuation analysis for liberia abstract the importance of energy consumption for growth and development calls for improved decision support for a sustainable energy transition given africa s dependence on fossil fuels the economic and environmental savings from research development and deployment of renewable energy technologies may be substantial although the benefits of renewable energy technologies research development funding may appear to be low assuming immediate deployment the uncertainty in the non renewable energy price and the flexibility over timing makes research development program more appealing this study develops different scenarios in order to quantify benefits provided by research development funding for renewable power generation in liberia by using real options pricing approach to estimate the value of renewable energy technologies while taking into account the uncertainty of fossil fuel prices and learning by doing in renewable energy technologies the optimal solution shows that renewable energy technologies are economically attractive especially when external costs are internalized however annual research development funding is low and should be raised significantly in order to guarantee the highest possible investment incentives with minimal expenditures the study also hypothesizes that with the likelihood of renewable energy to replace non renewable energy renewable power use in liberia can potentially reduce carbon dioxide emissions by approximately 13 9 by 2015 compared to the 2008 levels the key insight provided by the real options analysis in this study is that while renewable energy may have inherent limitations such as seasonality of supply low energy content and capacity factor issues they still hold a significant amount of value which can only be detected when externalities are internalized thus underscoring the need for external costs related policies

can the urban poor afford modern energy the case of ethiopia abstract comparing rough measures of costs of using modern fuels and purchasing power of the urban poor in ethiopia this article finds that while kerosene is relatively cheap even for the very poor electricity is extremely expensive even for the relatively well to do the upper stratum of the poor may have the purchasing power to access butane gas in addition the article examines the relevance of the energy ladder hypothesis generally both at the aggregate level and for individual urban areas the prediction from the hypothesis holds but our results indicate that the relevance of the hypothesis weakens on lower levels of aggregation implying significant inter city variations finally demand equations for each fuel are econometrically estimated and the elasticities are used to examine price and income effects the budget elasticities indicate that with economic growth the demand for traditional fuels will increase in addition the cross price elasticities show that increase in the price of a traditional fuel mainly shifts demand towards other traditional fuels rather than towards modern fuels this slows down the transition towards modern fuels the article concludes by presenting policy recommendations arising from the analysis

rural electrification in zambia a policy and institutional analysis abstract zambia is well endowed with hydropower and other energy resources which could facilitate production of electricity for both urban and rural areas of the country the country has an installed electricity generation capacity of 1786 mw and undeveloped hydropower potential of over 6000 mw in the last few years demand has been growing and it is anticipated to outstrip supply in 2008 the load growth is attributed to increased mining activities and development of the industrial base the country is also endowed with abundant natural resources such as arable land water minerals and wildlife with the available resource base electricity along with other social and economic infrastructure such as roads and telecommunications could facilitate increased economic activities in rural areas electricity could be used for crop irrigation agro processing small scale mining and to facilitate tourism however rural electrification re faces many challenges such as long distances from existing power stations to targeted rural areas low population densities high poverty levels and low skills availability these and other factors have contributed to continued low levels of access to electricity in rural areas of the country measures so far undertaken to facilitate access to electricity in rural areas of zambia include the adoption of a new national energy policy nep in 1994 with regard to the electricity sector and re in particular the nep was aimed at facilitating increased access by liberalising and restructuring the electricity market and promoting the use of low cost technologies and decentralised renewable energies to facilitate implementation of the new policy the government established a legal and institutional framework by enacting new legislation namely the electricity act and the energy regulation act in 1995 the electricity act provided for liberalisation and regulation of the electricity sector while the energy regulation act provided for the establishment of an independent regulator so as to stimulate private sector participation and efficiency in addition a rural electrification fund ref and associated administration mechanism was established in 1995 however re continued to experience many challenges in 2003 the government enacted the rural electrification act leading to the establishment of an agency dedicated to re this paper analyses the policy legal and institutional measures implemented in zambia and assesses their potential or effectiveness to tackle some of the challenges facing re in the country so as to increase access and affordability

equilibrium wage distributions the observation that different firms charge different prices for what appears to be the same commodity or pay different wages for what appears to be equivalent labour has long been explained in economics by a reference to imperfect information this paper is concerned with characterising market equilibrium with imperfect information we do not present a general theory rather we develop in some detail an example of importance in its own right imperfect information in the labour market several properties of our example in particular the existence of equilibria with price wage dispersion unemployment excess supply of labour positive profits multiple equilibria and the nonoptimality or some of all of the equilibria are of more general validity other results may not be this paper is concerned with two kinds of imperfect information a individuals may not know the wage paid in any particular firm or whether there is a vacancy in any particular firm until they apply for a job 1 b there are several characteristics besides the wage rate associated with a job which are important to the individual some like the normal length of a work week become known when the individual applies for the job information about other characteristics e g personalities of colleagues is acquired only gradually there is one important difference between the two kinds of imperfect in