global trading versus linking architectures for international emissions trading abstract international emissions trading is widely seen as an indispensable policy pillar of climate change mitigation stern n 2007 the economics of climate change the stern review cambridge university press new york this article analyzes five different types of trading architectures classified into two top down unfccc driven and three bottom up driven by individual countries or regions approaches the two types of approaches are characterized by a trade off between environmental effectiveness and political feasibility respectively whereas their relative cost effectiveness depends on implementation details bottom up architectures constitute imperfect substitutes for top down architectures in terms of environmental effectiveness and thus remain mere fallback options however especially the formal linking architecture can act as complement in terms of cost effectiveness

credible research designs for minimum wage studies a response to neumark salas and wascher the authors assess the critique by neumark salas and wascher 2014 of minimum wage studies that found small effects on teen employment data from 1979 to 2014 contradict nsw the authors show th

the risk of second tier supplier failures in serial supply chains implications for order policies and distributor autonomy abstract as organizations decrease inventory the potential impact of a supply disruption increases however due to supply chain structural changes the likelihood of a disruption may be less additionally independent supply chain actors may react to policy changes changing supply chain configurations and perhaps reducing loss magnitudes if risk is a product of likelihood and magnitude does higher inventory reduce an organization s supply related risk this paper examines the supply risk issue within the context of a second tier supply failure and is grounded in inventory and resource dependency theories by evaluating risk assessment in a simulation environment exploratory findings suggest that increased inventory in a tiered supply chain can sometimes increase supply risk rather than decrease it managerial insights into the effects of supply chain stability and coordination are provided by taking a systems perspective of supply risk management organizations will be better able to manage supply risk concerns

customer order information leadtimes and inventories we have an inventory to manage the scenario is standard in all respects save one instead of arriving unannounced customers provide advance warning of their demands how should we use this information and what is its effect on system performance the answers turn out to be strikingly simple there are very simple policies which perform effectively in some cases optimally also such demand leadtimes improve performance in precisely the same way that replenishment leadtimes degrade it

labor market monopsony there has been a renewed interest in monopsony in labor markets in recent years that includes both the traditional static approach to monopsony ably reviewed by boal and ransom 1997 and the new approach to monopsony with more attention paid to dynamic issues developed in detail by manning 2003 the articles presented in this supplement highlight both approaches and illustrate the range of labor market settings in which the exercise of monopsony power may be important the first use of the term monopsony in economics is widely attributed to robinson 1969 robinson conceived of monopsony as analogous to monopoly whereas monopoly refers to the case of a single seller confronted in a market by many buyers monopsony refers to the case of a single buyer confronted in a market by many sellers just as the monopolist faces a downward sloping demand curve for his product and

minimum wage effects on labor market outcomes under search matching and endogenous contact rates building upon a continuous time model of search with nash bargaining in a stationary environment we analyze the effect of changes in minimum wages on labor market outcomes and welfare although minimum wage increases may or may not lead to increases in unemployment in our model they can be welfare improving to labor market participants on both the supply and demand sides of the labor market we discuss identification of the model using current population survey data on accepted wages and unemployment durations and show that by incorporating a limited amount of information from the demand side of the market it is possible to obtain credible and precise estimates of all primitive parameters we show that the optimal minimum wage in 1996 depends critically on whether or not contact rates can be considered to be exogenous and we note that the limited variation in minimum wages makes testing this assumption problematic

an empirical analysis of the co2 shadow price in chinese thermal power enterprises abstract this paper estimates the shadow price of co2 and explores its determinants for thermal power enterprises in china using a parametric quadratic directional distance function we evaluate the inefficiency and shadow price of co2 for 124 power enterprises in 2004 applying deterministic and econometric methods a regression analysis is undertaken to examine the factors that drive shadow prices our results indicate that there are large inefficiencies in terms of electricity production and co2 emissions the shadow price is a negative function of firm size age and coal share and is positively correlated with the technology level this correlation between shadow prices and its determinants is not sensitive to changing assumptions regarding directional vectors although such changes do alter the distribution of shadow prices the large variation witnessed in shadow prices across power enterprises argues in favor of market based regulation such as an emissions trading system as opposed to the command and control regulation currently used in china to minimize overall abatement cost

employment effects of minimum and subminimum wages panel data on state minimum wage laws using panel data on state minimum wage laws and economic conditions for the years 1973 89 the authors reevaluate existing evidence on the effects of a minimum wage on employment their estimates indicate that a 10 increase in the minimum wage causes a decline of 1 2 in employment among teenagers and a decline of 1 5 2 in employment for young adults similar to the ranges suggested by earlier time series studies the authors also find evidence that youth subminimum wage provisions enacted by state legislatures moderate the disemployment effects of minimum wages on teenagers

on the relationship between entropy demand uncertainty and expected loss abstract we analyze the effect of demand uncertainty as measured by entropy on expected costs in a stochastic inventory model existing models studying demand variability s impact use either stochastic ordering techniques or use variance as a measure of uncertainty due to both axiomatic appeal and recent use of entropy in the operations management literature this paper develops entropy s use as a demand uncertainty measure our key contribution is an insightful proof quantifying how costs are non increasing when entropy is reduced

determining the optimal size of supply base with the consideration of risks of supply disruptions abstract determining the optimal size of the supply base has haunted managers for years a small supply base gives rise to the risk of supply disruption whereas a large supply base increases the fixed cost in this paper we consider the risks of supply disruption due to occurrence of super semi super and unique events in order to formulate a model to determine the optimal size of supply base we depict the model in a decision tree like structure and forward a tabular method of solution that obviates the need avoids evaluation of a majority of non optimal solutions and thus overcomes the problem of dimensionality

getting handcuffs on an octopus theoretical work on minimum wage policy emphasizes labor market dynamics but the resulting implications for worker mobility remain largely untested the authors show that in the teenage labor market higher minimum wage standards reduce worker flows and increase job stability furthermore they find that the employment effects of a relatively higher minimum wage vary considerably across markets with different levels of turnover and labor market tightness results help to explain the small effects of minimum wage standards on employment commonly found in the aggregate data and are consistent with labor market models that involve search frictions

burden sharing in a greenhouse egalitarianism and sovereignty reconciled the allocation of emission entitlements across countries is the single most controversial issue in international climate policy extreme positions within the policy debate range from entitlements based on current emission patterns sovereignty to entitlements based on equal per capita allocations egalitarianism this paper shows that gradual convergence from sovereignty towards egalitarianism could provide a pragmatic solution to the equity debate when combined with international emissions trading the convergence approach stands out for offering the developing countries substantial incentives for participation in the international greenhouse gas abatement effort without imposing excessive burdens on the industrialized countries

industry level emission trading between power producers in the eu in this paper we investigate how restrictions for emission trading to the energy intensive power sector will affect the magnitude and distribution of abatement costs across eu countries vis a vis a comprehensive eu emission trading regime we find that emission trading between european power sectors allows the harvest of a major part of the efficiency gains provided by full trade as compared to strictly domestic action however trade restrictions may create a more unequal distribution of abatement costs across member states than is the case for a comprehensive trade regime the reason for this is that restricted permit trade enhances the secondary terms of trade benefits to eu member countries with low marginal abatement costs at the expense of the other eu member states

bayes solution to dynamic inventory models under unknown demand distribution this paper considers the periodic review inventory problem for which one or more parameters of the demand distribution are unknown with a known prior distribution chosen from the natural conjugate

the credibility revolution in empirical economics how better research design is taking the con out of econometrics since edward leamer s memorable 1983 paper let s take the con out of econometrics empirical microeconomics has experienced a credibility revolution while leamer s suggested remedy sensitivity analysis has played a role in this we argue that the primary engine driving improvement has been a focus on the quality of empirical research designs the advantages of a good research design are perhaps most easily apparent in research using random assignment we begin with an overview of leamer s 1983 critique and his proposed remedies we then turn to the key factors we see contributing to improved empirical work including the availability of more and better data along with advances in theoretical econometric understanding but especially the fact that research design has moved front and center in much of empirical micro we offer a brief digression into macroeconomics and industrial organization where progress by our lights is less dramatic although there is work in both fields that we find encouraging finally we discuss the view that the design pendulum has swung too far critics of design driven studies argue that in pursuit of clean and credible research designs researchers seek good answers instead of good questions we briefly respond to this concern which worries us little

a capacitated production inventory model with periodic demand for a single product single stage capacitated production inventory model with stochastic periodic cyclic demand we find the optimal policy and characterize some of its properties we study the finite horizon the discounted infinite horizon and the infinite horizon average cases a simulation based optimization method is provided to compute the optimal parameters based on a numerical study several insights into the model are also provided

value of information in capacitated supply chains we incorporate information flow between a supplier and a retailer in a two echelon model that captures the capacitated setting of a typical supply chain we consider three situations 1 a traditional model where there is no information to the supplier prior to a demand to him except for past data 2 the supplier knows the s s policy used by the retailer as well as the end item demand distribution and 3 the supplier has full information about the state of the retailer order up to policies continue to be optimal for models with information flow for the finite horizon the infinite horizon discounted and the infinite horizon average cost cases study of these three models enables us to understand the relationships between capacity inventory and information at the supplier level as well as how they are affected by the retailer s s s values and end item demand distribution we estimate the savings at the supplier due to information flow and study when information is most beneficial

market power and hot air in international emissions trading the impacts of us withdrawal from the kyoto protocol ten years after the initial climate change convention from rio in 1992 the industrialized world is finally likely to ratify the kyoto protocol which will impose legally binding greenhouse gas emission reductions on the developed world however the kyoto protocol will enter into force without the usa which withdrew under president bush in march 2001 accounting for hot air and market power of the former soviet union on emission permit markets it is shown that us withdrawal has important consequences on environmental effectiveness compliance costs and excess costs of market power under the kyoto protocol non compliance of the usa implies a dramatic decrease in environmental effectiveness as well as compliance costs of oecd countries whereas the former soviet union and transitional economies in eastern europe suffer from a huge decline in permit sales revenues excess costs of market power in permit trade increase in relative terms but decline substantially in absolute terms due to us withdrawal pol

inventory control in a fluctuating demand environment we present an inventory model where the demand rate varies with an underlying state of the world variable this variable can represent economic fluctuations or stages in the product life cycle for example we derive some basic characteristics of optimal policies and develop algorithms for computing them in addition we show that certain monotonicity patterns in the problem data are reflected in the optimal policies

information distortion in a supply chain the bullwhip effect this article originally appeared in management science april 1997 volume 43 number 4 pp 546 558 published by the institute of management sciences consider a series of companies in a supply chain each of whom orders from its immediate upstream member in this setting inbound orders from a downstream member serve as a valuable informational input to upstream production and inventory decisions this paper claims that the information transferred in the form of orders tends to be distorted and can misguide upstream members in their inventory and production decisions in particular the variance of orders may be larger than that of sales and distortion tends to increase as one moves upstream a phenomenon termed bullwhip effect this paper analyzes four sources of the bullwhip effect demand signal processing rationing game order batching and price variations actions that can be taken to mitigate the detrimental impact of this distortion are also discussed

the elasticity of labor supply at the establishment level monopsonistic wage setting power requires that the supply of labor directed toward individual establishments is upward sloping this study utilizes institutional features to identify the supply curve the elasticity of labor supply is estimated using data for the norwegian teacher labor market in a period where the only variation in the wage level was determined centrally and with information on whether there is excess demand or not at the school level in fixed effects models the supply elasticity faced by individual schools is estimated to about 1 4 and is in the range 1 0 1 9 in different model specification

is there a case for carbon based border tax adjustment an applied general equilibrium analysis concern that unilateral greenhouse gas ghg emission reductions could foster carbon leakage and undermine the international competitiveness of domestic industry has led to growing calls for carbon based border tax adjustments btas this article uses a global general equilibrium model to assess the economic effects of btas and comes to three main conclusions first btas can reduce carbon leakage if the coalition of countries taking action to reduce ghg emissions is small because in this case leakage while typically small mainly occurs through international trade competitiveness losses rather than through declines in world fossil fuel prices second even though the economic effects of btas vary somewhat depending on how they are implemented their welfare impact is typically small and slightly negative at the world level third and perhaps more strikingly btas do not necessarily curb the output losses incurred by the domestic energy intensive industries eiis they are intended to protect in the

analysis of an inventory system under supply uncertainty in this paper we analyze a periodic review single item inventory model under supply uncertainty the objective is to minimize expected holding and backorder costs over a finite planning horizon under the supply constraints the uncertainty in supply is modeled using a three point probability mass function the supply is either completely available partially available or the supply is unavailable machine breakdowns shortages in the capacity of the supplier strikes etc are possible causes of uncertainty in supply we demonstrate various properties of the expected cost function and show the optimality of order up to type policies using a stochastic dynamic programming formulation under the assumption of a bernoulli type supply process in which the supply is either completely available or unavailable and when the demand is deterministic and dynamic we provide a newsboy like formula which explicitly characterizes the optimal order up to levels an algorithm is given that computes the optimal inventory levels over the planning horizon extensions and computational analysis are presented for the case where the partial supply availability has positive probability of occurrence

market power in emissions trading markets ruled by a multiple unit double auction further experimental evidence we discuss selected methodological problems of previous double auction da experiments and test the hypothesis that a multiple unit double auction muda is able to prevent market power in an emissions trading market additionally we analyze how the information subjects receive about the market structure and different levels of subjects experience influence the behavior based on a larger number of independent observations than analyzed in previous studies the experiment generates two main results first emissions trading markets ruled by a muda realize a high degree of efficiency even under market power conditions however a muda is in general not able to restrict market power we observe persistent price discrimination in two market power environments i e the distribution of profits is strongly shifted in favor of the strong market side without greatly harming efficiency this result is independent of the information to subjects about the market structure second when subjects are experienced the efficiency is higher and the ability of the strong market side to exercise market power declines strongly however the variability of behavior is large and the strong market side is still able to realize supracompetitive profits in some groups

minimum wage effects on employment substitution and the teenage labor supply evidence from personnel data using personnel data from a large us retail firm i examine the firm s response to the 1996 federal minimum wage increase compulsory increases in average wages had negative but statistically insignificant effects on overall employment however increases in the relative wages of teenagers led to significant increases in the relative employment of teenagers especially younger and more affluent teenagers further analysis suggests a pattern consistent with noncompetitive models where the legislation affected mainly the wages of teenagers and so was only moderately binding it led both to higher teenage labor market participation and to higher absolute employment of teenagers

minimum wage shocks employment flows and labor market frictions we provide the first estimates of the effects of minimum wages on employment flows in the u s labor market identifying the impact using policy discontinuities at state borders we find that minimum wages have a sizable negative effect on employment flows but not stocks separations and accessions fall among affected workers we interpret our findings using a job ladder model in which minimum wage increases can reduce job to job transitions we find that a standard calibration of the model generates predicted relative magnitudes of the employment stock and flow elasticities that are very close to our reduced form estimates

marginal abatement costs of co2 emission reductions geographical flexibility and concrete ceilings an assessment using the poles model abstract the kyoto protocol envisage the setting up of flexibility mechanisms allowing annex b countries to fulfil their commitments to reducing greenhouse gases with respect for the principle of economic efficiency the current negotiations relate in particular to the possibility of setting up a system of tradable emissions permits for annex b countries and also of introducing ceilings to trade this paper analyses the stakes and economic potential of adopting this instrument both for those countries that made commitments in kyoto and for developing countries it is based on a formal approach that allows for a consistent framework of analysis the emission permit market is in fact simulated on the basis of a reference scenario and of marginal abatement cost curves and estimated by the poles model after analysing these marginal abatement cost curves and comparing them with those produced by other models we explore two different configurations for a competitive market a market limited to the annex b countries and a world market the results produced by the model show that widening the market to include developing countries is more effective than the annex b market solution it reduces the cost of implementing kyoto for oecd countries and at the same time allows the countries of the south to benefit from selling the permits this research also shows that introducing restrictions on exchanges for annex b countries could have a counter productive redistribution effect with the ethical argument that underlies that particular measure

welfare consequences of emission credit trading programs abstract the welfare consequences of moving from a command and control approach to pollution control to an emission credit trading program that attains the same environmental quality are shown to depend on the competitiveness of the output markets in which polluting firms compete if the output markets are competitive then the introduction of trading increases aggregate welfare in contrast if the output markets in which these firms participate are not competitive then the adoption of an emission credit trading program may reduce social welfare this is so even if emission credit markets are perfectly competitive

exclusionary manipulation of markets for pollution rights abstract strategic price manipulation can affect the distribution of transferable pollution rights across polluters and the efficiency of pollution control efforts prior research has concentrated on market manipulation by firms seeking only to minimize the sum of pollution rights costs and pollution abatement costs in this paper we explore the potential for the exclusionary manipulation of pollution permit markets intended to drive up the costs of one s rivals and we distinguish between the resource allocation effects of exclusionary manipulation and cost minimizing manipulation we find that exclusionary manipulation can sometimes worsen and sometimes ameliorate the abatement inefficiency which occurs under cost minimizing manipulation and that an overbuying rule can obviate or at least limit damages from this form of strategic behavior

is there monopsony in the labor market evidence from a natural experiment recent theoretical and empirical advances have renewed interest in monopsonistic models of the labor market however there is little direct empirical support for these models we use an exogenous change in wages at department of veterans affairs va hospitals as a natural experiment to investigate the extent of monopsony in the nurse labor market we estimate that labor supply to individual hospitals is quite inelastic with short run elasticity around 0 1 we also find that non va hospitals responded to the va wage change by changing their own wages

climate policy induced investments in developing countries the implications of investment risks international climate policy has assigned the leading role in emissions abatement to the industrialized countries while developing countries remain uncommitted to binding emission reduction targets however cooperation between the industrialized and the developing world through joint implementation of emission abatement promises substantial economic gains to both parties in this context the policy debate on joint implementation has addressed the question of how investment risks to project based emission crediting between industrialized countries and developing countries affect the magnitude and distribution of such gains in our quantitative analysis we find that the incorporation of country specific investment risks induces rather small changes vis a vis a situation where investment risks are neglected only if investors go for high safety of returns is there a distinct decline in the overall volume of emission crediting and the associated total economic benefits while the welfare effects of risk incorporation for industrialized countries are unequivocally negative the implications across developing countries are ambiguous whereas low risk developing countries attract higher project volumes and benefit from higher effective prices per emission credit compared to a reference scenario without risk the opposite applies to high risk countries sensitivity analysis with respect to higher risk estimates show that shifts in the comparative advantage of emission abatement against high risk countries may become dramatic as only very low cost mitigation projects will be realized driving down the country s benefits from emission crediting to the advantage of low risk developing countries this result is supported by empirical evidence on regional imbalances of activities implemented jointly under the pilot phase of the kyoto protocol

retailer policy uncertainty reduction and supply chain performance abstract we investigate how the retailer s inventory policy affects the total cost of a serial supply chain when the retailer uses the locally optimal s s policy there is randomness in order time and order quantity to the supplier whereas the supplier sees randomness only in order quantity for the suboptimal r t policy and only in order time for another suboptimal q r policy using an extensive computational study we find that the suboptimal policies perform better from the total supply chain perspective the benefit of policy changes is magnified when the retailer costs are low when the supplier costs are high and when there is information sharing

market power and transferable property rights the appeal of using markets as a means of allocating scarce resources stems in large part from the assumption that a market will approximate the competitive ideal when competition is not a foregone conclusion the question naturally arises as to how a firm might manipulate the market to its own advantage this paper analyzes the issue of market power in the context of markets for transferable property rights first a model is developed that explains how a single firm with market power might exercise its influence this is followed by an examination of the model in the context of a particular policy problem the control of particulate sulfates in the los angeles region

intertemporal emission trading with a dominant agent how does a restriction on borrowing affect efficiency in this paper we analyze how restricting intertemporal trading by prohibiting borrowing of emissions permits affects the ability of a dominant agent to exploit its market power we show that the monopolist could take advantage of the constraint on borrowing by not distributing the sale of permits cost effectively across periods furthermore we show that a constant present value price over time does not imply a cost effective distribution of abatement permit sales across periods

strengthening state capabilities the role of financial incentives in the call to public service we study a recent recruitment drive for public sector positions in mexico different salaries were announced randomly across recruitment sites and job offers were subsequently randomized screening relied on exams designed to measure applicants intellectual ability personality and motivation this allows the first experimental estimates of i the role of financial incentives in attracting a larger and more qualified pool of applicants ii the elasticity of the labor supply facing the employer and iii the role of job attributes distance attractiveness of the municipal environment in helping fill vacancies as well as the role of wages in helping fill positions in less attractive municipalities a theoretical model guides each stage of the empirical inquiry we find that higher wages attract more able applicants as measured by their iq personality and proclivity towards public sector work i e we find no evidence of adverse selection effects on motivation higher wage offers also increased acceptance rates implying a labor supply elasticity of around 2 and some degree of monopsony power distance and worse municipal characteristics strongly decrease acceptance rates but higher wages help bridge the recruitment gap in worse municipalities

stalking information bayesian inventory management with unobserved lost sales retailers are frequently uncertain about the underlying demand distribution of a new product when taking the empirical bayesian approach of scarf 1959 they simultaneously stock the product over time and learn about the distribution assuming that unmet demand is lost and unobserved this learning must be based on observing sales rather than demand which differs from sales in the event of a stockout using the framework and results of braden and freimer 1991 the cumulative learning about the underlying demand distribution is captured by two parameters a scale parameter that reflects the predicted size of the underlying market and a shape parameter that indicates both the size of the market and the precision with which the underlying distribution is known an important simplification result of scarf 1960 and azoury 1985 which allows the scale parameter to be removed from the optimization is shown to extend to this setting we present examples that reveal two interesting phenomena 1 a retailer may hope that compared to stocking out realized demand will be strictly less than the stock level even though stocking out would signal a stochastically larger demand distribution and 2 it can be optimal to drop a product after a period of successful sales we also present specific conditions under which the following results hold 1 investment in excess stocks to enhance learning will occur in every dynamic problem and 2 a product is never dropped after a period of poor sales the model is extended to multiple independent markets whose distributions depend proportionately on a single unknown parameter we argue that smaller markets should be given better service as an effective means of acquiring information

the impact of minimum wages on labour market transitions we investigate dierences in labour market transition rates in high versus low minimum wage regimes using canadian data spanning 1979 to 2008 the data include consistent questions on job tenure and reason for job separation for the whole period over the same time frame there were over 140 minimum wage changes in canada we nd that higher minimum wages are associated with lower hiring rates but also with lower job separation rates importantly the reduced separation rates are due mainly to reductions in layos occur in the rst 6 months of a job and are present for unskilled workers of all ages our estimates imply that a 10 increase in the minimum wage generates a 3 9 reduction in the layo rate we present a search and matching model that ts with these patterns and test its implications overall our results imply

tradeable emission permits regulations in the presence of imperfectly competitive product markets welfare implications in the present paper we analyse the interaction of a competitive market for emission permits with an oligopolistic product market it is well known that a competitive permits market achieves the cost minimizing distribution of abatement effort among the polluting firms for a given reduction in emissions however when the product market is oligopolistic it may redistribute production inefficiently among firms it has been suggested that this inefficiency can outweigh the gains obtained from using emission permits instead of command and control although this argument is clearly correct under full information it is shown in the present paper that it reverses under incomplete information in particular it is shown that when tradeable emission permits are specified according to the standard textbook example they yield higher social welfare than the command and control regulation

revisiting the minimum wage employment debate throwing out the baby with the bathwater we revisit the minimum wage employment debate which is as old as the department of labor in particular we assess new studies claiming that the standard panel data approach used in much of the new minimum wage research is flawed because it fails to account for spatial heterogeneity these new studies use research designs intended to control for this heterogeneity and conclude that minimum wages in the united states have not reduced employment we explore the ability of these research designs to isolate reliable identifying information and test the untested assumptions in this new research about the construction of better control groups our evidence points to serious problems with these research designs we conclude that the evidence still shows that minimum wages pose a tradeoff of higher wages for some against job losses for others and that policymakers need to bear this tradeoff in mind when making decisions about increasing the minimum wage

beyond kyoto backstop technologies and endogenous prices on co2 permits and fossil fuels this paper analyses the markets for fossil fuels given that the limits the kyoto protocol sets on co2 emissions from annex b countries extend beyond 2008 2012 a forward looking model with endogenous prices for fossil fuels is applied under different assumptions concerning the technological progress for a carbon free backstop technology both the time profile of the international permit price needed for the kyoto forever targets as well as the implications through reduced demand and lower producer prices for fossil fuels are calculated the permit price has to rise at least up to 2030 in order to fulfil the emission targets from then on the necessary permit price shows different future developments dependent on when the backstop technology starts to replace oil since changes in the availability of the backstop technology shift the time profile of the permit price the loss of petroleum wealth for oil and gas producers varies between the scenarios but is never more than 20 findings indicate that the

myopic policies for some inventory models with uncertain demand distributions the majority of papers on stochastic inventory theory make the assumption that the distribution of consumer demand in each time period is known with certainty while this assumption is unsupported in many applied contexts it is conventionally held that more realistic models are more difficult to solve and will not yield simple operational policies this paper shows that a simple inventory policy based upon a critical fractile can be optimal or near optimal in some inventory models with parameter adaptive demand processes in these some parameter of the demand distribution is not known with certainty and estimates of the parameter are updated in a statistical fashion as demand is observed through time examples include exponentially smoothed forecasts and bayesian updating of parameter estimates bounds on the value loss relative to optimal cost when using the critical fractile policy can be calculated directly from the problem data some numerical examples illustrate the technique

a panel data heterogeneous bayesian estimation of environmental kuznets curves for co2 emissions this article investigates the environmental kuznets curves ekc for co2 emissions in a panel of 109 countries during the period 1959 to 2001 the length of the series makes the application of a heterogeneous estimator suitable from an econometric point of view the results based on the hierarchical bayes estimator show that different ekc dynamics are associated with the different sub samples of countries considered on average more industrialized countries show evidence of ekc in quadratic specifications which nevertheless are probably evolving into an n shape based on their cubic specification nevertheless it is worth noting that the eu and not the umbrella group led by us has been driving currently observed ekc like shapes the latter is associated to monotonic income co2 dynamics the eu shows a clear ekc shape evidence for less developed countries consistently shows that co2 emissions rise positively with income though there are some signs of an ekc analyses of future performance neverthe

wage differentials employer size and unemployment the unique equilibrium solution to a game in which a continuum of individual employers choose permanent wage offers and a continuum of workers search by sequentially sampling from the set of offers is characterized wage dispersion is a robust outcome provided that workers search while employed as well as when unemployed the unique nondegenerate equilibrium distribution of wage offers is constructed for three cases 1 identical workers and employers 2 identical employers and an atomless distribution of worker supply prices and 3 identical workers and an atomless distribution of job productivities copyright 1998 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

monopsony power in migrant labor markets evidence from the united arab emirates by exploiting a reform in the united arab emirates that relaxed restrictions on employer transitions we provide new estimates of the monopsony power of firms over migrant workers our results show that the reform increased incumbent migrants earnings and firm retention this occurs despite an increase in employer transitions and is driven by a fall in country exits while the outcomes of incumbents improved the reform decreased demand for new migrants and lowered their earnings these results are consistent with a model of monopsony in which firms face upward sloping labor supply curves for both new recruits in source countries and incumbent migrants

the case for international emission trade in the absence of cooperative climate policy we evaluate the efficacy of international trade in carbon emission permits when countries are guided strictly by their national self interest to do so we construct a calibrated general equilibrium model that jointly describes the world economy and the strategic incentives that guide the design of national abatement policies countries decisions about their participation in a trading system and about their initial permit endowment are made noncooperatively so a priori it is not clear that permit trade will induce participation in international abatement agreements or that participation will result in significant environmental gains despite this we find that emission trade agreements can be effective that smaller groupings pairing developing and developed world partners often perform better than agreements with larger rosters and that general equilibrium responses play an important role in shaping these outcomes