inequality and the dynamics of public opinion the self reinforcing link between economic inequality and mass preferences this article assesses the influence of income inequality on the public s policy mood recent work has produced divergent perspectives on the relationship between inequality public opinion and government redistribution one group of scholars suggests that unequal representation of different income groups reproduces inequality as politicians respond to the preferences of the rich another group of scholars pays relatively little attention to distributional outcomes but shows that government is generally just as responsive to the poor as to the rich utilizing theoretical insights from comparative political economy and time series data from 1952 to 2006 supplemented with cross sectional analysis where appropriate we show that economic inequality is in fact self reinforcing but that this is fully consistent with the idea that government tends to respond equally to rich and poor in its policy enactments

is there a glass ceiling in sweden using 1998 data we show that the gender log wage gap in sweden increases throughout the wage distribution and accelerates in the upper tail we interpret this as a strong glass ceiling effect we use quantile regression decompositions to examine whether this pattern can be ascribed primarily to gender differences in labor market characteristics or in the rewards to those characteristics even after extensive controls for gender differences in age education both level and field sector industry and occupation we find that the glass ceiling effect we see in the raw data persists to a considerable extent

competition and coalition formation of renewable power producers we investigate group formations and strategic behaviors of renewable power producers in electricity markets these producers currently bid into the day ahead market in a conservative fashion because of the real time risk associated with not meeting their bid amount it has been suggested in the literature that producers would bid less conservatively if they can form large groups to take advantages of spatial diversity to reduce the uncertainty in their aggregate output we show that large groups of renewable producers would act strategically to lower the aggregate output because of market power to maximize renewable power production we characterize the trade off between market power and generation uncertainty as a function of the size of the groups we show there is a sweet spot in the sense that there exists groups that are large enough to achieve the uncertainty reduction of the grand coalition but are small enough such that they have no significant market power we consider both independent and correlated forecast errors under a fixed real time penalty we also consider a real time market where both selling and buying of energy are allowed we validate our claims using pjm and nrel data

evaluating a stochastic programming based bidding model for a multireservoir system hydropower producers need to schedule when to release water from reservoirs and participate in wholesale electricity markets where the day ahead production is physically traded a mixed integer linear stochastic model for bid optimization and short term production allocation is developed and tested through a simulation procedure implemented for a complex real life river system the stochastic bid model sees uncertainty in both spot market prices and inflow to the reservoirs the same simulation procedure is also implemented for a practice based deterministic heuristic method similar to what is currently used for bid determination in the industry and the results are compared the stochastic approach gives improvements in terms of higher obtained average price and higher total value than the deterministic alternative it also performs well in terms of startup costs in the presence of river flow travel delay the practice based method is even more outperformed by the stochastic model

stochastic modelling of renewable energy sources from operators point of view a survey abstract high penetration of renewable energy sources especially weather dependent sources has increased the power systems uncertainties for any analysis in power systems such as planning and operation it is essential to confront the stochastic nature of these sources in order to get much more precise results since operators need proper strategies and methods to decline negative effects of the stochastic behaviour of renewable power generators such as total operation cost growth this paper provides a review of different state of the art approaches from the operator s viewpoint for handling the stochastic behaviour of renewable sources hence in this paper three different strategies are categorized for stochastic analysis of these sources the first strategy is mathematical modelling including stochastic dependency and independency multi dimensional dependence forecast and scenarios afterwards demand side management which is one of the other approaches for dealing with these uncertainties is investigated and different demand response programs and some methods to model them are presented finally the effect of different electricity market schemes and relevant optimization methods to mitigate the variations of renewable energy sources are discussed the study demonstrates that an operator should choose one or a combination of these three approaches based on its requirements

strategic offering for a wind power producer as a result of subsidies and technological maturity renewable electricity producers have grown in some jurisdictions to clearly dominant positions in the market under this context we propose an offering strategy for a wind power producer with market power that participates in the day ahead market as a price maker and in the balancing market as a deviator uncertainty pertaining to wind power production and balancing market price is represented through a set of correlated scenarios the proposed model is a stochastic mathematical program with equilibrium constraints mpec that can be recast as a tractable mixed integer linear programming milp problem which is solvable using available optimization software results from an illustrative example and two case studies show the effectiveness of the proposed model

distributed stochastic market clearing with high penetration wind power integrating renewable energy into the modern power grid requires risk cognizant dispatch of resources to account for the stochastic availability of renewables toward this goal day ahead stochastic market clearing with high penetration wind energy is pursued in this paper based on the dc optimal power flow opf the objective is to minimize the social cost which consists of conventional generation costs end user disutility as well as a risk measure of the system re dispatching cost capitalizing on the conditional value at risk cvar the novel model is able to mitigate the potentially high risk of the recourse actions to compensate wind forecast errors the resulting convex optimization task is tackled via a distribution free sample average based approximation to bypass the prohibitively complex high dimensional integration furthermore to cope with possibly large scale dispatchable loads a fast distributed solver is developed with guaranteed convergence using the alternating direction method of multipliers admm numerical results tested on a modified benchmark system are reported to corroborate the merits of the novel framework and proposed approaches

revealed political power this paper adopts a revealed preference approach to the question of what can be inferred about bias in a political system we examine a dynamic environment in which individuals dier by income each period long run preference profiles are unobserved to an outside observer but are known to belong to a well behaved class in which individual preferences are ordered by income in each state policy data is summarized by a markov policy rule the observer makes inferences about the underlying distribution of political power as if political power were derived from a wealth weighted voting system with weights that can vary across states the weights determine the nature and magnitude of the wealth bias positive weights on relative income in any period indicate an elitist bias in the political system whereas negative weights indicate a populist one we ask what class of weighted systems can rationalize a given policy rule as a weightedmajority outcome each period our first result shows that without further knowledge all forms of bias are possible any markov policy rule can be shown to be rationalized by any system of wealth weighted voting an additional single crossing restriction on preferences can however rule out certain weighting systems we then augment policy data with polling data and show that the set of rationalizing wealth weights are bounded above and below in some cases polls can provide information about the change in political inequality across time

economics of pooling small local electricity prosumers lcoe self consumption abstract the arrival of small scale decentralized energy installations coincides with the emergence of so called prosumers entities households that are producer and consumer of energy in one this research focuses on an electricity prosumer model in the context of the uk market levelized cost of electricity lcoe for photovoltaic pv and wind energy will be modeled for six uk sites additionally self consumption levels for two different load profiles and technologies will be estimated per site the simulations are modeled with homer software and multiple inputs will be varied including natural resource equipment cost maintenance cost equipment life expectancy cost of capital project life and load profiles the modeled self consumption levels show significant differences and varied between 31 and 72 depending on load profile itself and re technologies mixes modeled the pooling of prosumers implied by lower load profile volatility proved to be beneficial to self consumption levels in the modeled scenarios up to 17 6 lcoe showed significant ranges depending on the input parameters and their combination 10 55 p kw h for pv and 2 19 p kw h for wind the combination of these factors is decisive for the final lcoe and the negative effects of less benign factors can be compensated by other parameters when compared to current electricity retail prices of around 15 p kw h around 97 of wind sites and around 4 of pv scenarios implied lcoe reached grid parity the self consumption levels and lcoe analysis indicate the viability of electricity prosumer models

pricing and the news vendor problem a review with extensions in the newsvendor problem a decision maker facing random demand for a perishable product decides how much of it to stock for a single selling period this simple problem with its intuitively appealing solution is a crucial building block of stochastic inventory theory which comprises a vast literature focusing on operational efficiency typically in this literature market parameters such as demand and selling price are exogenous however incorporating these factors into the mode l can provide an excellent vehicle for examining how operational problems interact with marketing issues to influence decision making at the firm level in this paper we examine an extension of the newsvendor problem in which stocking quantity and selling price are set simultaneously we provide a comprehensive review that synthesizes existing results for the single period problem and develop additional results to enrich the existing knowledge base we also review and develop insight into a dynamic inventory extension of this problem and motivate the applicability of such models

intraday trading of wind energy in this paper we tackle the problem of a wind power producer participating in a short term electricity market that allows for the continuous but potentially illiquid intraday trading of energy considering the realistic case of a wind farm operating in the western danish price area of nord pool we build a simple but effective algorithm for the wind power producer to fully benefit from the elbas intraday market we then investigate the sensitivity of the obtained benefits to the maximum volume of energy the wind power producer is willing to trade in the intraday market the ultimate aim of the trade either to decrease energy imbalances or to increase profits and to the installed capacity of the wind farm our numerical results reveal that the wind power producer can substantially increase his revenues by partaking in the intraday market but with diminishing returns to scale a result that we attribute to the low liquidity of elbas

stochastic security for operations planning with significant wind power generation in their attempt to cut down on greenhouse gas emissions from electricity generation several countries are committed to install wind power generation up to and beyond the 10 20 penetration mark however the large scale integration of wind power represents a challenge for power system operations planning because wind power 1 cannot be dispatched in the classical sense and 2 its output varies as weather conditions change this warrants the investigation of alternative short term power system operations planning methods capable of better coping with the nature of wind generation while maintaining or even improving the current reliability and economic performance of power systems to this end this paper formulates a short term forward electricity market clearing problem with stochastic security capable of accounting for nondispatchable and variable wind power generation sources the principal benefit of this stochastic operation planning approach is that when compared to a deterministic worst case scenario planning philosophy it allows greater wind power penetration without sacrificing security

energy market design for renewable resources imbalance settlements and efficiency robustness tradeoffs this paper examines optimal energy market bidding behavior for stochastic resources when energy imbalance payments are determined endogenously from market clearing conditions some electricity markets require wind producers to settle day ahead offers based on their real time energy production this is usually justified by economic and cost causation principles without considering the effects of these policies on curtailment and system balancing costs under these real time settlement requirements demand and wind forecast errors impact the effective penalty price so strategic behavior affects the penalty price paid by producers this paper formulates a two stage game where producers place energy bids in the day ahead market and then choose a curtailment level in real time and it derives the symmetric subgame perfect equilibrium strategy for producers it details how supply curve convexity and resource correlation can lead wind producers to bid conservatively even when they are not risk averse the results show that market based pricing mechanisms improve tradeoffs between system efficiency and mean squared bid error as compared to the case where penalty levels are determined by alternative policies suggesting additional benefits of market based penalty prices beyond those previously studied

is there a glass ceiling over europe exploring the gender pay gap across the wages distribution using harmonised data from the european union household panel we analyse gender pay gaps by sector across the wages distribution for ten countries we find that the mean gender pay gap in the raw data typically hides large variations in the gap across the wages distribution we use quantile regression qr techniques to control for the effects of individual and job characteristics at different points of the distribution and calculate the part of the gap attributable to differing returns between men and women we find that first gender pay gaps are typically bigger at the top of the wage distribution a finding that is consistent with the existence of glass ceilings for some countries gender pay gaps are also bigger at the bottom of the wage distribution a finding that is consistent with sticky floors third the gender pay gap is typically higher at the top than the bottom end of the wage distribution suggesting that glass ceilings are more prevalent than sticky floors and that these prevail in the majority of our countries fourth the gender pay gap differs significantly across the public and the private sector wages distribution for each of our eu countries

winds of change how high wind penetrations will affect investment incentives in the gb electricity sector abstract wind power is widely expected to expand rapidly in britain over the next decade large amounts of variable wind power on the system will increase market risks with prices more volatile and load factors for conventional thermal plant lower and more uncertain this extra market risk may discourage investment in generation capacity financial viability for thermal plant will be increasingly dependent on price spikes during periods of low wind increased price risk will also make investment in other forms of low carbon generation e g nuclear power more challenging a number of policies can reduce the extent to which generators are exposed to market risks and encourage investment however market risks play a fundamental role in shaping efficient investment and dispatch patterns in a liberalised market therefore measures to improve price signals and market functioning such as a stronger carbon price and developing more responsive demand are desirable however the scale of the investment challenge and increased risk mean targeted measures to reduce although not eliminate risk exposure such as capacity mechanisms and fixed price schemes may have increasing merit the challenge for policy is to strike the right balance between market and planned approaches

large scale utilization of wind power in china obstacles of conflict between market and planning the traditional strict planning system that regulates china s power market dominates power industry operations however a series of market oriented reforms since 1997 call for more decentralized decision making by individual market participants moreover with the rapid growth of wind power in china the strict planning system has become one of the significant factors that has curtailed the generation of wind power which contradicts with the original purpose of using the government s strong control abilities to promote wind power development in this paper we first present the reasons why market mechanisms are important for large scale utilization of wind power by using a case analysis of the northeast grid and then we illustrate the impact of conflicts between strict planning and market mechanisms on large scale wind power utilization last we explore how to promote coordination between markets and planning to realize large scale wind power utilization in china we argue that important measures include implementing flexible power pricing mechanisms instead of the current fixed pricing approach formulating a more reasonable mechanism for distributing benefits and costs and designing an appropriate market structure for large scale wind power utilization to promote market liquidity and to send clear market equilibrium signals

local matching of flexible load in smart grids abstract today s power systems are experiencing a transition from primarily fossil fuel based generation toward greater shares of renewable energy sources it becomes increasingly costly to manage the resulting uncertainty and variability in power system operations solely through flexible generation assets incorporating demand side flexibility through appropriately designed incentive structures can add an additional lever to balance demand and supply based on a supply model using empirical wind generation data and a discrete model of flexible demand with temporal constraints we design and evaluate a local online market mechanism for matching flexible load and uncertain supply under this mechanism truthful reporting of flexibility is a dominant strategy for consumers reducing payments and increasing the likelihood of allocation suppliers during periods of scarce supply benefit from elevated critical value payments as a result of flexibility induced competition on the demand side we find that for a wide range of the key parameters supply capacity flexibility level the cost of ensuring incentive compatibility in a smart grid market relative to the welfare optimal matching is relatively small this suggests that local matching of demand and supply can be organized in a decentral manner in the presence of a sufficiently flexible demand side extending the stylized demand model to include complementary demand structures we demonstrate that decentral matching induces only minor efficiency losses if demand is sufficiently flexible furthermore by accounting for physical grid limitations we show that flexibility and grid capacity exhibit complementary characteristics

trading wind generation in short term energy markets even with state of the art forecasting methods the short term generation of wind farms cannot be predicted with a high degree of accuracy in a market situation these forecasting errors lead to commercial risk through imbalance costs when advance contracting this situation is one that needs to be addressed due to the steady increase in the amount of grid connected wind generation combined with the rise of deregulated market orientated electricity systems in the presence of imbalance prices and uncertain generation a method is required to determine the optimum level of contract energy to be sold on the advance markets such a method is presented here using markov probabilities for a wind farm and demonstrates substantial reductions in the imbalance costs the effect of market closure delays and forecasting window lengths are also shown

a simple solution to the identification problem in detailed wage decompositions i introduction oaxaca and ransom 1999 show that the oaxaca decomposition suffers from one nagging conceptual problem the detailed oaxaca decomposition of wage differentials is not invariant to the choice of reference group when dummy variables are used 1 that is if one uses dummy variable s then the detailed coefficients effect attributed to dummy variables is not invariant to the choice of the omitted group s 2 this invariance or identification problem is well known to labor economists and has plagued decomposition and discrimination analysis for a long time 3 this article proposes a simple and practical solution to this identification invariance problem the solution is based on the intuitive idea that if alternative reference groups yield different estimates of the characteristics and coefficients effects for each individual variable then it is natural to obtain estimates of the two effects for every possible specification of the reference groups and take the average of the estimates of the two effects with various reference groups as the true contributions of individual variables to wage differentials a close inspection shows that averaging the two effects in the decomposition equation with varying reference groups the averaging approach is equivalent to finding average estimates of constant and dummy variables in wage equations with varying reference groups and then using the average estimates to calculate the oaxaca decomposition equation researchers may react a bit negatively to this suggestion because it could be quite cumbersome and tedious to estimate wage equations permuting the choice of reference groups this article shows that there is no need to estimate multiple wage equations one set of regression estimates is sufficient to resolve the identification problem in the detailed decompositions that is the average of the estimates with varying reference groups can be easily calculated by using only one set of regression estimates with any specific reference group s the identification problem for the detailed decomposition disappears once the contribution of the dummy variables and the constant in the regression equations are identified 4 ii identification problem and invariant decomposition an illustration to understand what the identification problem in the detailed wage decomposition is i will first illustrate the problem with a simple example suppose that there are three categories and the regression equation has only a constant and two dummy variables on the right hand side where the reference group is the first category 5 that is 1 y sub i alpha sub i 3 summation over k 2 d sub ki beta sub ki e sub i where y is log wages and i a or b for two comparison groups coefficients for two dummy variables taking category one as the reference group are estimated using ordinary least squares ols regression and are reported in the second column of table 1 for sample a and for sample b note that the coefficient of the reference group category 1 is restricted to zero similarly i may change my reference group specification and estimate the wage equation two more times the estimates taking category 2 or 3 as the reference group are reported on the next two columns because i have three sets of estimates with varying reference groups i may decompose the wage differentials 0 15 0 76 0 61 into characteristics and coefficients effects three times the characteristics effect delta sub x 1 and coefficients effects delta sub beta 1 are specified as follows when category 1 is the reference group delta sub x 1 summation sup 3 sub k 2 bar d sub ka bar d sub kb beta sub kb and delta sub beta 1 alpha sub a alpha sub b summation sup 3 sub k 2 bar d sub ka beta sub ka beta sub kb

offering strategy of wind power producer a multi stage risk constrained approach given the significant amount of installed generation capacity based on wind power and also due to current economic downturn the subsidies and incentives that have been widely used by wind power producers to recover their investment costs have decreased and are even expected to disappear in the near future in these conditions wind power producers need to develop offering strategies to make their investments profitable counting solely on the market this paper proposes a multi stage risk constrained stochastic complementarity model to derive the optimal offering strategy of a wind power producer that participates in both the day ahead and the balancing markets uncertainties concerning wind power productions market prices demands bids and rivals offers are efficiently modeled using a set of scenarios the conditional value at risk metric is used to model the profit risk associated with the offering decisions the proposed model is recast as a tractable mixed integer linear programming program solvable using available branch and cut algorithms results of a case study are reported and discussed to show the effectiveness and applicability of the proposed approach

the gender wage gap among recent post secondary graduates in canada a distributional approach using the national graduates survey we examine the trends in the gender wage gap among recent post secondary graduates in canada between 1988 and 2007 female graduates earn on average 6 14 less than males during the period two to five years after graduation decompositions show that observable personal characteristics and job attributes can explain only a small portion of the wage gap we also find that men earn more than women at every point of the distribution interestingly the wage difference shrank in the lower half of the distribution in recent years while it increased in the upper half l ecart salarial entre les sexes chez les nouveaux diplomes postsecondaires une approche distributionnelle a l aide de l enquete nationale aupres des diplomes nous examinons les tendances dans l ecart salarial entre les sexes chez les nouveaux diplomes postsecondaires au canada entre 1988 et 2007 les femmes diplomees gagnent en moyenne de 6 a 14 moins que les hommes durant les 2 a 5 ans suivant l obtention du diplome des decompositions montrent que les caracteristiques personnelles et les attributs de l emploi observables ne peuvent expliquer qu une petite partie de l ecart salarial nous trouvons aussi que les hommes touchent plus que les femmes a chaque point de la distribution salariale de maniere interessante la difference de salaire a diminue dans la moitie inferieure de la distribution lors des annees recentes alors qu elle a augmente dans la moitie superieure

demand response application by strategic wind power producers this paper considers a wind power producer playing strategically in a day ahead market while willing to set demand response dr contracts with a dr aggregator to this end a bilevel problem including a single leader and two followers is formulated the wind power producer is the leader aiming at maximizing its profit through offering into a day ahead market and clearing its deviation in a balancing market the strategic behavior of the producer in the day ahead market is modeled through the market clearing process follower 1 in addition the dr aggregator behavior is modeled through a revenue function in which the aggregator is able to sell its dr product to the wind power producer other competitors and the day ahead market follower 2 the overall problem is a stochastic mathematical program with equilibrium constraints mpec in which wind power production and imbalance prices are associated with uncertainty the problem is then transformed into a linear programming approach a case of the nordic market is chosen to assess the validity of the given problem

a large amount of idle capacity under rapid expansion policy analysis on the dilemma of wind power utilization in china abstract wind power installation in china has increased rapidly since 2004 however wind power usage remains relatively low resulting in a lot of idle capacity beginning in 2007 in this paper we determine the main framework of china s current wind power policies and illustrate how these policies led to the rapid installation expansion accompanied by large idle capacity building on this we explore how to alleviate the high installation low wind power usage conflict in china we establish optimal models to i analyze wind power and power grid company behavior ii demonstrate the impact of china s current policies on power and grid companies and iii clarify the causes and mechanisms resulting in high growth and low wind power capacity usage our analysis shows that the incentive incompatibility of current policies which enticed power companies to pursue installation expansion regardless of quality while inhibiting grid companies from improving connectivity transmission and scheduling technology is the primary cause for such large scale idle capacity the results of our study suggest that the fundamental way to scale up wind power utilization is to enhance policy incentive compatibility which mainly includes i distributing revenues and diversifying risk fairly between power and grid companies and ii motivating power companies to address demand fluctuation actively

bringing wind energy to market wind energy is a rapidly growing source of renewable energy generation however the current extra market approach to its assimilation into the electric grid will not scale at deep penetration levels in this paper we investigate how an independent wind power producer might optimally offer its variable power into a competitive electricity market for energy starting with a stochastic model for wind power production and a model for a perfectly competitive two settlement market we derive explicit formulae for optimal contract offerings and the corresponding optimal expected profit as wind is an inherently variable source of energy we explore the sensitivity of optimal expected profit to uncertainty in the underlying wind process we also examine the role of forecast information and recourse markets in this setting we quantify the role of reserves in increasing reliability of offered contracts and obtain analytical expressions for marginal profits resulting from investments in improved forecasting and local auxiliary generation the formulae make explicit the relationship between price signals and the value of such firming strategies

coalitional aggregation of wind power this paper explores scenarios in which independent wind power producers form willing coalitions to exploit the reduction in aggregate power output variability obtainable through geographic diversity in the setting of a two settlement electricity market we examine the advantage gained through optimal coalitional contract offering strategies for quantity risk reduction we show that a group of independent wind power producers can always improve their expected profit by cooperatively offering their aggregated power using coalitional game theory we identify sharing mechanisms to fairly allocate the profits to coalition members we show that the resulting coalitional game is balanced guaranteeing that the core of the game is necessarily nonempty in addition we propose a profit sharing mechanism that minimizes the worst case dissatisfaction to recover an imputation in the core finally we illustrate our theoretical results with empirical studies using data from five representative wind farms in upstate new york

minimization of imbalance cost trading wind power on the short term power market present power markets are designed for trading conventional generation for wind generation to participate in a short term energy market lengthy wind power production forecasts are required although wind speed forecasting techniques are constantly improving wind speed forecasts are never perfect and resulting wind power forecast errors imply imbalance costs for wind farm owners in this paper a new method for minimization of imbalance costs is developed stochastic programming is used to generate optimal wind power production bids for a short term power market a wind power forecast error is represented as a stochastic process the imbalance costs resulting from this strategy are then compared to the case when wind power production bids on a short term power market are based directly on a wind speed forecast

the distribution of the male female earnings differential 1970 1990 the authors examine the male female earnings differential between 1970 and 1990 their objective is to provide consistent estimates that can be compared and interpreted over time and to assess the sensitivity of their results to alternative specifications the authors find that women made modest gains over the period standard decomposition techniques reveal that gender differences in observable characteristics do not explain much of the earnings differential most of the improvement in women s relative earnings has come by a decline in the unexplained component the authors also find that the differential varies systematically across age and education groups and across high and low income women coauthors are dwayne benjamin andree desaulniers and mary grant

fixed feed in tariff versus premium a review of the current spanish system a b s t r a c t since 1998 the spanish government established a feed in system where res e generators could choose between two alternatives fixed feed in tariff and premium nowadays all res e 1 can be sold in the electricity market getting an additional premium except for solar photovoltaic one important novelty established in 2007 is a cap and floor system for facilities under the premium option the aim of this paper is to analyze and compare these two alternative options fixed fit and premiums which coexist at the same time in spain describe the evolution of both systems and evaluate its performance the introduction of this support system in spain led to very good results in terms of res e deployment the main advantage of the premium option is that it is a scheme integrated in the electricity market one disadvantage is that it can occasionally lead to overcompensation one way to try to avoid it is to set a cap value in order to evaluate the performance of this dual support system not only res e deployment has been assessed but also the policy stability the adequacy of res e production to the electricity demand pattern and the changes in the investors behaviour

gender role attitudes and the labour market outcomes of women across oecd countries this paper uses data from the world value surveys 1990 1995 1999 to investigate the impact of gender role attitudes and work values on women s labour market outcomes across 25 oecd countries anti egalitarian views are found to display the strongest negative association with female employment rates and the gender pay gap these views are however softening among recent cohorts on the other hand perceptions of women s role as homemakers which are likely formed in youth and linked to religious ideology are more persistent over time they could be implicated in the recent slowdown of the gender convergence in pay finally the unavoidable clash between family values and egalitarian views that takes the form of an inner conflict for many women the so called mother s guilt is another obstacle in the path towards greater gender equality in the labour market copyright 2005 oxford university press

the impact of wind generation on wholesale electricity prices in the hydro rich pacific northwest extant literature documents that wind generation can reduce wholesale electricity market prices by displacing conventional generation but how large is the wholesale price effect of wind generation in an electricity market dominated by hydroelectric generation we explore this question by analyzing the impact of wind generation on wholesale electricity prices in the pacific northwest region of the united states this hydro rich system tends to be energy limited rather than capacity constrained with its marginal generation during the hydro runoff season often a hydro unit instead of a natural gas fired unit we find that increased wind generation reduces wholesale market prices by a small but statistically significant amount while a hydro rich system can integrate wind generation at a lower cost than a thermal dominated region the direct economic benefits to end users from greater investment in wind power may be negligible

in and out of the labour market long term income consequences of child related interruptions to women s paid work why do canadian mothers have lower incomes than women who have never had children microdata from the 1995 gss allow examination of two hypotheses 1 mothers have spent more time out of the labour force thus acquiring less human capital 2 higher levels of unpaid work lead to fatigue and or scheduling difficulties measuring work history does little to account for the family gap the estimated child penalty is reduced by allowing for human capital depreciation and controlling for unpaid work hours but the two hypotheses together cannot entirely explain the gap jel classification j0 j3 entrees et sorties marche du travail et consequences a long terme des interruptions dans l experience sur le marche du travail a cause des enfants ce memoire se demande pourquoi les femmes canadiennes qui ont eu des enfants ont des revenus plus bas que ceux des femmes qui n en ont pas eus les microdonnees de l enquete sociale generale de 1995 de statistiques canada permettent d examiner deux hypotheses 1 les meres ont passe plus de temps en dehors de la main d oeuvre active et donc ont accumule moins de capital humain ou 2 des niveaux plus eleves de travail non remunere peuvent entrainer fatigue ou difficultes d organisation du temps des efforts pour construire une meilleure image de l experience de travail des femmes ne permettent pas d expliquer cet ecart familial meme si la possibilite qu il y ait depreciation du capital humain reduit la penalisation attachee au fait d avoir un enfant en particulier si l interruption dans l experience sur le marche du travail est suivie d un changement d emploi le nombre hebdomadaire d heures de travail non paye est relie negativement aux revenus et si l on normalise pour tenir compte des heures de travail non paye cela reduit la penalisation attachee au fait d avoir un enfant cependant les deux hypotheses combinees ne suffisent pas pour expliquer l ecart

cost causation based allocations of costs for market integration of renewable energy an important problem in modern electrical power systems is the inherent variability and uncertainty of renewable energy resources allocating the costs generated by the variable resources in a just and reasonable manner is crucial for economic efficiency in this paper we develop an axiomatic framework for allocating the deviation costs generated by variable resources using the cost causation based principle the cost causation principle has a long historical tradition in electrical energy systems and has been proved to provide economic efficiency we apply the new cost causation based framework to allocate the cost in the production deviation of a group of renewable energy producers and thereby help promote the market integration of renewable energy the resulting cost allocation framework is then applied to five wind power producers bidding in the iberian electricity market in europe using real data on wind speeds and market prices

constituency opinion and congressional policy making the reagan defense buildup representatives votes on a series of defense budget roll calls in the first year of the reagan administration s pentagon buildup are related to constituency opinions on defense spending during the 1980 election campaign the strong aggregate constituency demand for increased defense spending in 1980 is estimated to have added almost 17 billion about 10 to the total fiscal year 1982 pentagon appropriation the impact of constituency opinion was largely independent of specific political circumstances differential responsiveness in districts with partisan turnover intense districtlevel competition and strong presidential coattails together accounted for less than 1 billion in additional appropriations with the remaining 16 billion attributable to across the board responsiveness by even the most safely incumbent representatives t he appeal of representative democracy hinges on the responsiveness of elected politicians to the preferences and interests of their constituents given the theoretical and practical significance of the connection between constituents opinions and their representatives legislative activities it is remarkable that the large and in some ways quite sophisticated empirical literature addressing this connection includes so few direct estimates of the relationship between constituency opinion and specific legislative outcomes 1 my aim here is to provide one such estimate the policy issue i have chosen to examine is the level of total pentagon spending in the first fy 1982 defense appropriations bill of the reagan administration that bill the first in a series of annual appropriations resulting in a 40 real increase in defense spending during reagan s first five years in office is of obvious political significance but the issue of defense spending is also especially interesting from a broader theoretical perspective because the strong public demand for a defense spending increase at the beginning of the reagan era provides unusual analytical leverage for assessing the potential impact of public opinion on the making of public policy i shall describe some alternative mechanisms of congressional responsiveness to constituency opinion briefly characterize the politics of defense at the beginning of the reagan era present my analysis of representatives preferences regarding fy 1982 defense appropriations relating those preferences to constituency opinions on the defense spending issue and to other political characteristics of the representatives and their districts extend the analysis of fy 1982 defense appropriations from the individual to the aggregate level in an attempt to estimate the impact of congressional responsiveness on the total level of pentagon appropriations and finally touch upon some of the implications of my analysis for the study of linkages between public opinion and public policy

coups corporations and classified information we estimate the impact of coups and top secret coup authorizations on asset prices of partially nationalized multinational companies that stood to benefit from u s backed coups stock returns of highly exposed firms reacted to coup authorizations classified as top secret the average cumulative abnormal return to a coup authorization was 9 over 4 days for a fully nationalized company rising to more than 13 over 16 days precoup authorizations accounted for a larger share of stock price increases than the actual coup events themselves there is no effect in the case of the widely publicized poorly executed cuban operations consistent with abnormal returns to coup authorizations reflecting credible private information we also introduce two new intuitive and easy to implement nonparametric tests that do not rely on asymptotic justifications

optimal bidding of a group of wind farms in day ahead markets through an external agent in deregulated electricity markets producers offer their energy to the day ahead market as the subsidies for renewable producers are becoming lower and lower they have to adapt to market prices this paper models the energy trading in the day ahead market for wind power producers different strategies are proposed for this purpose 1 several wind farms offering their energy separately to the day ahead market 2 the same strategy as in 1 but compensating the imbalance among different wind farms and 3 a joint offer involving several wind farms through an external agent in order to minimize the imbalances between the offer and the final power generation the strategies are modeled with stochastic mixed integer linear programming and conditional value at risk is used to consider the risk assessment the expected profit including risk aversion is maximized for each wind power producer and for the set of wind power producers in the case of a joint offer a comparison of the different cases is described in detail in a case study and relevant conclusions are provided

a stochastic two settlement equilibrium model for electricity markets with wind generation incentives to encourage the uptake of renewable energy generation have fostered wind energy in many power systems these incentives usually take the form of market instruments e g feed in tariff or premium that are not directly amenable to optimization representations of the market in this paper we propose an equilibrium model of the short term market to address the impact of wind operation under different structural assumptions the model is formulated for several price taking risk averse firms in competition it accounts for wind generation uncertainty and embeds a representation of the day ahead and balancing mechanisms the consumer is modeled by a linear inverse demand function we focus on feed in premium as the incentive to wind as this is the instrument most favored today in european discussions the model is formulated as a stochastic equilibrium problem where the karush kuhn tucker kkt conditions from the optimization problem of each firm are simultaneously solved together with market clearing conditions on energy capacity for reserve and energy for reserve the problem for each firm consists of a two stage stochastic optimization problem with a recourse function based on the conditional value at risk cvar as a risk measure due to price taking assumptions the model is a single stage complementarity problem it is implemented and solved using the software gams an example based on a stylized simplification of the spanish power market and motivated by the impact of wind penetration on the revenue of conventional plants is used to illustrate the proposed approach

medium term multimarket optimization for virtual power plants a stochastic based decision environment this paper presents a decision making tool tailored for a portfolio manager aiming at maximizing its profit by participating in both energy and balancing services markets the proposed formulation is modular and flexible so as to comply with any portfolio configuration and to follow evolutions of the market regulation policy detailed formulations of both medium term i e typically from one week up to one year ahead and short term i e day ahead perspectives are jointly considered and solved using surrogate based optimization the objective is to adequately account for the interdependencies and possible conflicting objectives between these time horizons then in order to overcome the resulting computational burden associated with the different sources of uncertainty an innovative method for generating time and space dependent scenarios is developed the approach is based on nonparametric copulas and in contrast to traditional methods allows including a large number of uncertain parameters into the formulation finally the procedure is tested and illustrated for a portfolio manager with diversified assets the case study is developed to emphasize the advantages of the proposed optimization tool in terms of accuracy and computational burden of the proposed models as well as subsequent generated profit

granger causality and the time series analysis of political relationships political scientists have employed causal modeling techniques for quite some time in most cases however they have relied on methods of a static cross sectional variety time series methods have been disseminated and applied but these have not been expressly causal the problem of assessing the causal character or direction of political relationships over time has not been addressed granger 1969 has suggested a notion of causality that is applicable in longitudinal analysis the study and application of granger s idea of causation now is widespread in economics and business this discussion evaluates the usefulness of applying granger causality in the study of political relationships granger s definition of causality is introduced several popular procedures for assessing granger causality are reviewed and certain problems surrounding interpretation of those empirical tests are elucidated the virtues and pitfalls of granger causal analysis then are illustrated in an analysis of an important topic in international political economy and also in a reanalysis of a recent granger causal investigation of arms races

performance pay and the white black wage gap we show that the reported tendency for performance pay to be associated with greater wage inequality at the top of the earnings distribution applies only to white workers this results in the white black wage differential among those in performance pay jobs growing over the earnings distribution even as the same differential shrinks over the distribution for those not in performance pay jobs we show that this remains true even when examining suitable counterfactuals that hold observables constant between whites and blacks we explore reasons behind our finding focusing on the interactions between discrimination unmeasured ability and selection

wind power offering strategy in day ahead markets employing demand response in a two stage plan this paper deals with wind power offering strategies in day ahead markets a new plan is proposed in which a wind power producer participates in the day ahead market while employing demand response dr to smooth its power variations in this context a new dr scheme is presented through which the wind power producer is able to achieve dr by establishing various dr agreements with dr aggregators the proposed offering plan involves two stages the first stage clears on the day ahead market the wind power producer decides on day ahead offers as well as dr agreements with the aggregator the second stage takes place on the balancing market in a successive approach the wind power producer determines its energy trading for each period until the whole day is covered additionally proper dr agreements for each period are confirmed here the proposed plan is formulated in a stochastic programming approach where its validity is assessed on a case of the nordic market

neoclassical realism and theories of foreign policy although international relations theory has been dominated for two decades by debates over theories of international politics recently there has been a surge of interest in theories of foreign policy these seek to explain not the pattern of outcomes of state interactions but rather the behavior of individual states the author surveys three prominent theories of foreign policy and shows how the works under review set out a compelling alternative one that updates and systematizes insights drawn from classical realist thought neoclassical realism argues that the scope and ambition of a country s foreign policy is driven first and foremost by the country s relative material power yet it contends that the impact of power capabilities on foreign policy is indirect and complex because systemic pressures must be translated through intervening unit level variables such as decision makers perceptions and state structure understanding the links between power and policy thus requires close examination of both the international and the domestic contexts within which foreign policy is formulated and implemented

economic assessment of the participation of wind generation in the secondary regulation market the aim of this paper is to analyze the profitability of wind technology as a potential participant in the frequency regulation specifically in the secondary regulation market the study is conducted for the spanish system using existing market rules however although this system has some peculiarities the main methodology could be applied in other systems firstly a bibliographical review of the relevant technical possibilities of this technology is carried out then a simulation study based on real data is conducted in order to evaluate the maximum possible incomes later a specific offer strategy is proposed and the income is estimated based on statistical modeling and checked by simulating its performance using the actual and forecasted productions of a wind portfolio it is concluded that under the current generation structure and regulatory framework in the spanish system the incomes obtained from the participation of wind technology would be modest however secondary regulation by wind generators might facilitate higher penetration levels of this technology in the long term with expected wind generation subsidies much reduced a greater need for regulation reserves and a possible increase in regulation prices regulation related incomes might become a sizeable fraction of the total income of wind generators

trading wind generation from short term probabilistic forecasts of wind power due to the fluctuating nature of the wind resource a wind power producer participating in a liberalized electricity market is subject to penalties related to regulation costs accurate forecasts of wind generation are therefore paramount for reducing such penalties and thus maximizing revenue despite the fact that increasing accuracy in spot forecasts may reduce penalties this paper shows that if such forecasts are accompanied with information on their uncertainty i e in the form of predictive distributions then this can be the basis for defining advanced strategies for market participation such strategies permit to further increase revenues and thus enhance competitiveness of wind generation compared to other forms of dispatchable generation this paper formulates a general methodology for deriving optimal bidding strategies based on probabilistic forecasts of wind generation as well as on modeling of the sensitivity a wind power producer may have to regulation costs the benefits resulting from the application of these strategies are clearly demonstrated on the test case of the participation of a multi mw wind farm in the dutch electricity market over a year

comprehensive value assessment of wind power by layer great emphasis has been placed on rational value assessment of wind power in system in recent times because there are different properties in various output levels of wind power there should also be different values this paper proposes a novel method for value assessment of wind power to get a more comprehensive and accurate evaluation wind power outputs are divided horizontally based on the wind layer model then comprehensive studies of cost and benefit are conducted layer by layer furthermore the detailed characteristics in layers storage benefit and value allocation are analyzed after that the sensitivities about the chosen system parameters region size and demand side participation are discussed at length the effectiveness and rationality of the model are proved by the case study the model assesses the value of wind power more precisely and profoundly which would provide significant guidance in the setting of price policy for wind power and market supervision

trade wars and trade talks when governments meet in the international arena their actions reflect the political situations at home previous studies of trade relations have focused on governments that are immune from political pressures and that act as benevolent servants of the public interest here we introduce domestic politics into the analysis of international economic relations we study the interactions between national leaders who are concerned both with providing a high standard of living to the general electorate and collecting campaign contributions from special interest groups our analysis sheds light on the determinants of the structure of protection in non cooperative and cooperative policy equilibria

matching as a tool to decompose wage gaps abstract this paper presents a methodology that uses matching comparisons to explain gender wage differences the approach emphasizes gender differences in the supports of the distributions of observable characteristics and provides insights into the distribution of unexplained gender pay differences this nonparametric alternative to the blinder oaxaca bo decomposition does not require the estimation of earnings equations and divides the gap into four additive elements two of these are analogous to the elements of the bo decomposition but computed only over the common support of the distributions of characteristics while the other two account for differences in the supports

wage discrimination in the nba evidence using free agent signings this article takes a step toward understanding potential causes of wage discrimination in an economy highly dependent on the service industry traditionally categorized within the service industry professional sport leagues such as the national basketball association nba provides a unique setting to examine the potential impact of race on salary we analyze free agency contract signings which allow us to better capture the determinants of players wages from 2011 to 2017 to investigate the prominence of wage discrimination in the nba using weighted linear regression models and the oaxaca blinder decomposition we find that black athletes are paid significantly less than their counterparts in addition we also identify the presence of consumer discrimination after controlling the exposure of a player to the audience which is observed through the interaction term between the share of msa population which is white and an identifier for whether a player is black

pros and cons of exposing renewables to electricity market risks a comparison of the market integration approaches in germany spain and the uk abstract the article examines how renewable electricity res e producers are integrated into the electricity market under the support legislations and regulatory frameworks of germany spain and the uk focus is on wind power which faces the highest market integration challenge of all res e the analysis shows that the three countries follow contrasting approaches of exposing res e producers to the market risks of forward electricity markets balancing markets and system planning requirements risk exposure is highest in the uk and lowest in germany from a policy maker s perspective there is a trade off between a high risk and a low risk approach when res e face high market risks a higher level of financial support is required to stimulate res e development than in a low risk environment but the exposure to market risks may also give an incentive to make efficient use of the respective market thus limiting the indirect costs to society the special characteristics of wind energy however put natural limits to the response of wind power plants to market prices and locational price signals and will increasingly influence electricity markets and grid infrastructure these interdependencies should be recognised in the design of res e policies and market regulations

the immigrant and native born wage distributions evidence from united states censuses recent studies document a large widening of the immigrant native born mean wage gap since about 1970 a trend that some observers ascribe to post 1965 changes in u s immigration policy these studies are limited however by their exclusive focus on men which ignores important gender differences in the wage gap and by the inadequacy of the mean wage for characterizing the gap when as in recent decades the wage distribution dramatically changes this study of recent immigrants examines changes across the entire wage distribution for both genders the authors find evidence based partly on gender differences that minimum wages strongly influenced the gap a counterfactual analysis also indicates that if recent immigrants in 1970 had faced the 1990 wage structure their wage distribution would have closely resembled that of recent immigrants in 1990 these and other results suggest that the increasing wage gap is linked to changes in the wage structure

pay differences among the highly paid the male female earnings gap in lawyers salaries this article uses very detailed information on graduates of the university of michigan law school to examine male female pay differences in that population men and women in this population have virtually identical human capital on graduation from law school allowing us to examine carefully the different impact of children and work history on men s and women s careers and earnings taking time from work in order to care for children reduces wages significantly but a rich set of controls including childcare work history school performance and job setting measures still leave one fourth to one third of the earnings gap unexplained

introduction epistemic communities and international policy coordination the growing technical uncertainties and complexities of problems of global concern have made international policy coordination not only increasingly necessary but also increasingly difficult if decision makers are unfamiliar with the technical aspects of a specific problem how do they define state interests and develop viable solutions what factors shape their behavior under conditions of uncertainty what are the origins of international institutions and how can we best study the processes through which international policy coordination and order emerge while a variety of analytic approaches have been used to address the problems of international cooperation the approaches have yielded only fragmentary insights at its core the study of policy coordination among states involves arguments about determinism versus free will and about the ways in which the international system is maintained and transformed among the overlapping topics of debate are whether national behavior is determined or broadly conditioned by system level factors unit level factors or some complex interplay between the two whether state policymakers can identify national interests and behave independently of pressures from the social groups they nominally represent and whether states respond consistently to opportunities to create defend or expand their own wealth and power to enhance collective material benefits or to promote nonmaterial values a related question of

identifying barriers to large scale integration of variable renewable electricity into the electricity market a literature review of market design abstract for reaching the 2 c climate target the robust growth of electricity generation from variable renewable energy sources vre in the power sector is expected to continue accommodation of the power system to the variable uncertain and locational dependent outputs of vre causes integration costs integrating vre into a well functioning electricity market can minimize integration costs and drive investments in vre and complementary flexible resources however the electricity market in the european union eu as currently designed seems incapable to deliver this end this paper aims to provide a comprehensive literature review of barriers to the large scale market integration of vre in the eu electricity market design based on the set up of the eu electricity market a framework was developed to incorporate the most pertinent market integration barriers and resulting market inefficiencies this paper concludes that an overhaul is needed for the current eu electricity market to address all barriers identified firstly a discrete auction intraday market a marginal pricing balancing market a two price imbalance settlement and a nodal pricing locational marginal pricing mechanism seem more promising in limiting integration costs secondly to support business cases of vre and complementary flexible resources in the electricity market a level playing field should be established and the price cap should be lifted up to the value of lost load voll meanwhile to fit vre s market participation a higher time resolution of trading products and later gate closure time in different submarkets would be required lastly feed in support schemes currently widely used for vre investments might be inconsistent with market integration as they increase integration costs and lock vre investments in a subsidy dependent pathway to avoid such lock in further investigation of alternative capacity based support schemes is recommended

the impact of european balancing rules on wind power economics and on short term bidding strategies abstract wind power represents a significant percentage of the european generation mix and this will increase to fulfill the renewable energy targets different balancing rules are applied to wind power among the countries for instance to what extent wind power producers wpps are responsible for the energy imbalances and how those imbalances are penalized this paper discusses those different rules and evaluates their effects on wpp bidding strategies to do so a quantitative analysis is presented for an offshore wind farm considering the differences in the balancing rules and prices of belgium denmark germany and the netherlands the quantitative approach consists of a stochastic optimization model that maximizes the profits of a wpp by trading in different markets day ahead and intraday and computes the final energy delivered the model considers uncertainties of most important parameters such as wind energy forecasts and prices at different time frames the results show that the imbalance pricing design and the allocation of balance responsibility significantly affect wpp revenues additionally wpps deviate differently from the expected energy depending on the balancing rules which can impact the system furthermore these balancing rules should be considered with other market regulations such as the design of support schemes

opportunity cost bidding by wind generators in forward markets analytical results wind generation must trade in forward electricity markets based on imperfect forecasts of its output and real time prices when the real time price differs for generators that are short and long the optimal forward strategy must be based on the opportunity costs of charges and payments in real time rather than a central estimate of wind output we present analytical results for wind s optimal forward strategy in the risk neutral case the optimal strategy is determined by the distribution of real time available wind capacity and the expected real time prices conditioned on the forward price and wind out turn our approach is simpler and more computationally efficient than formulations requiring specification of full joint distributions or a large set of scenarios informative closed form examples are derived for particular specifications of the wind price dependence structure in the usual case of uncertain forward prices the optimal bidding strategy generally consists of a bid curve for wind power rather than a fixed quantity bid a discussion of the risk averse problem is also provided an analytical result is available for aversion to production volume risk however we doubt whether wind owners should be risk averse with respect to the income from a single settlement period given the large number of such periods in a year

policy instruments fostering wind energy projects a multi perspective evaluation approach abstract during the last decade a large number of policy instruments have been developed and implemented all over europe aiming at supporting renewable energy project development however the success of the different policy approaches varies significantly given the very different mechanisms of the diverse instruments the design or the selection of appropriate instruments may cause methodological difficulties in order to support instrument selection economists have developed several evaluation criteria however this paper states that most of the typically proposed and applied criteria catalogues still neglect the interests and requirements of important stakeholder groups this paper therefore proposes a more integrated evaluation approach taking into account the different interests of all relevant stakeholder groups in the three fields renewable energy business especially wind industry policy making and conventional power business

optimal management and sizing of energy storage under dynamic pricing for the efficient integration of renewable energy we address the optimal energy storage management and sizing problem in the presence of renewable energy and dynamic pricing associated with electricity from the grid we formulate the problem as a stochastic dynamic program that aims to minimize the long run average cost of electricity used and investment in storage if any while satisfying all the demand we model storage with ramp constraints conversion losses dissipation losses and an investment cost we prove the existence of an optimal storage management policy under mild assumptions and show that it has a dual threshold structure under this policy we derive structural results which indicate that the marginal value from storage decreases with its size and that the optimal storage size can be computed efficiently we prove a rather surprising result as we characterize the maximum value of storage under constant prices and i i d net demand processes if the storage is a profitable investment then the ratio of the amortized cost of storage to the constant price is less than 1 4 we further perform sensitivity analysis on the size of optimal storage and its gain via a case study finally with a computational study on real data we demonstrate significant savings with energy storage

cost of service segmentation of energy consumers uncertainty in consumption is a key challenge at energy utility companies which are faced with balancing highly stochastic demand with increasingly volatile supply characterized by significant penetration rates of intermittent renewable sources this paper proposes a methodology to quantify uncertainty in consumption that highlights the dependence of the cost of service with volatility in demand we use a large and rich dataset of consumption time series to provide evidence that there is a substantial degree of high level structure in the statistics of consumption across users which may be partially explained by certain characteristics of the users to uncover this structure we propose a new technique for extracting typical statistical signatures of consumption energy demand distributions edds that is based on clustering distributions using a fast approximated algorithm we next study the factors influencing the choice of consumption signature and identify certain types of appliances and behaviors related to appliance operation that are most predictive finally we comment on how structure in consumption statistics may be used to target residential energy efficiency programs to achieve greatest impact in curtailing cost of service

analysis of the imbalance price scheme in the spanish electricity market a wind power test case this work investigates the interaction between wind power and electricity markets the paper is focused on balancing markets pricing policies the proposal of a new imbalance price scheme is included and conveniently evaluated this proposed scheme tries to minimise the use of ancillary services to compensate for deviations in searching for a more efficient market design the effectiveness of imbalance prices as market signals is also examined and policy recommendations regarding imbalance services are discussed two test cases are included that analyse the participation of a wind power producer in the spanish electricity market using a stochastic optimisation strategy for this purpose the uncertainty of the variables is considered i e wind power production and prediction intraday and imbalance prices test cases were run with real data for 10 months and realistic results are presented along with a hypothetical test case the regulation of the imbalance prices may not be adequate for the spanish electricity market because an error drop is not sufficiently encouraged therefore we suggest the application of a new imbalance price scheme which includes an additional constraint the conclusions of this paper can be assumed to be general policy recommendations

pool strategy of a price maker wind power producer we consider the problem of a wind power producer trading energy in short term electricity markets the producer is a price taker in the day ahead market but a price maker in the balancing market and aims at optimizing its expected revenues from these market floors the problem is formulated as a mathematical program with equilibrium constraints mpec and cast as a mixed integer linear program milp which can be solved employing off the shelf optimization software the optimal bid is shown to deliver significantly improved performance compared to traditional bids such as the conditional mean or median forecast of wind power distribution finally sensitivity analyses are carried out to assess the impact on the offering strategy of the producer s penetration in the market of the correlation between wind power production and residual system deviation and of the shape of the forecast distribution of wind power production

u s defense spending and the soviet estimate there is a glaring and potentially important discontinuity surrounding discussions of u s defense expenditure policy making on the one hand a growing body of empirically based research questions whether the u s reacts in any significant fashion to the military expenditures of the soviet union on the other hand defense policy makers routinely justify defense increases as a response to similar increases by the soviet union the discontinuity is resolved in the context of a multistep model of the defense expenditure policy making process that incorporates a new estimate of soviet defense spending and mass public opinion once formulated the model provides answers to the following two questions 1 does the u s insofar as defense spending is concerned react to the military expenditures of the soviet union 2 if so what is the magnitude of the reaction the answers indicate that not only does the u s react to estimated soviet defense spending but that the reaction is directly responsible for a very substantial portion of the post 1978 increases in u s military expenditures

who influences u s foreign policy research in international relations has identified a variety of actors who appear to influence u s foreign policy including experts and epistemic communities organized interests especially business and labor and ordinary citizens or public opinion this research however has often focused on a single factor at a time rather than systematically testing the relative importance of alternative possible influences using extensive survey data gathered over three decades we conduct a comparative test attempting to account for the expressed foreign policy preferences of policy makers by means of the preferences of the general public and those of several distinct sets of elites the results of cross sectional and time lagged analyses suggest that u s foreign policy is most heavily and consistently influenced by internationally oriented business leaders followed by experts who however may themselves be influenced by business labor appears to have significant but smaller impacts the general public seems to have considerably less effect except under particular conditions these results generally hold over several different analytical models including two observation time series and different clusters of issues economic military and diplomatic with some variations across different institutional settings the u s house senate and executive branch

wind aggregation via risky power markets aggregation of diverse wind power sources can effectively reduce their uncertainty and hence the cost of wind energy integration a risky power contract is proposed by which wind power producers wpps can trade uncertain future power for efficient wind aggregation a two settlement market with both the risky power contract and a conventional firm power contract is shown to have a unique competitive equilibrium ce characterized in closed form the marginal contribution and diversity contribution of each wpp to the group of all wpps are fairly reflected in the profit earned by this wpp at the ce moreover the ce achieves the same total profit as achieved by a grand coalition of wpps in a coalitional game setting the profit allocation induced by the ce is always in the core and is achieved via a non cooperative risky power market the benefits of the risky power market are demonstrated using wind generation and locational marginal price data for ten wpps in the pjm interconnection

electricity market participation of wind farms the success story of the spanish pragmatism abstract in the last 10 years more than 15 gw of wind power asociacion empresarial eolica spanish wind energy association nota de prensa press release 17 de enero de 2008 http www aeeolica org doc np 080117 espana supera los 15000 mw eolicos pdf have been installed in spain of which more than 3 5 gw in 2007 furthermore plans are to reach 20 gw by 2010 and there are expectations of an installed capacity exceeding 40 gw by 2020 this article will present the innovative solutions for technical and economical integration that allow to reach such high level wind penetration objectives the system peaks at around 44 gw and is almost isolated it will be described how the regulation has evolved from a pure feed in tariff to a market premium option where technical and economic integration has been a priority today approximately 97 of installed wind capacity accesses the spanish wholesale electricity market market integration has been crucial sending the correct signals to participants to look for the optimum technical solutions technical improvements have come from both wind power producers fault ride through capabilities visibility and controllability of wind power power production forecasting reactive power control and the system operator specific control centre dedicated to renewable energy sources res new security analysis tools gaining technical confidence of wind capabilities

operational strategies for a portfolio of wind farms and chp plants in a two price balancing market in this paper we explore the portfolio effect of a system consisting of a combined heat and power chp plant and a wind farm the goal is to increase the overall profit of the portfolio by reducing imbalances and consequently their implicit penalty in a two price balancing market for electricity we investigate two different operational strategies which differ in whether the chp plant and the wind farm are operated jointly or independently and we evaluate their economic performance on a real case study based on a chp wind system located in the western part of denmark we present a comprehensive mathematical model for describing the different heat and power production units of the chp plant and suggest different ways of determining its operation in a setup with two trading floors a day ahead market and a balancing market we build a simulation framework that runs in a rolling horizon fashion so that forecasts for heat demand wind power production and market prices are updated at each iteration we conclude that the portfolio strategy is the most profitable due to the two price structure of the balancing market this encourages producers to handle their imbalances outside the market

short term strategies for dutch wind power producers to reduce imbalance costs the paper assesses bidding strategies for a wind power producer in the netherlands to this end a three stage stochastic optimization framework is used maximizing wind power producer s profit using the day ahead and cross border intraday market taking into account available interconnection capacity results show that the wind power producer can increase its profits by trading on the intraday market and under certain imbalance prices by intentionally creating imbalances it has been considered uncertainties about prices power forecast and interconnection capacity at the day ahead and intraday timeframes

evaluating interconnector investments in the north european electricity system considering fluctuating wind power penetration with increasing amounts of power generation from intermittent sources like wind transmission planning has not only to account for the expected load curve but also for the stochasticity of volatile power infeeds moreover investments in power generation are no longer centrally planned in deregulated power markets but rather decided on competitive grounds by individual power companies this poses particular challenges when it comes to evaluating the benefits of increased interconnection capacities in large scale systems like the european transmission system within this article an approach is presented which allows assessing the benefits of interconnector investments in the presence of stochastic power infeed and endogenous power plant investments this model uses typical days and hours as well as recombining trees to represent both load and infeed fluctuations an application is presented covering 30 european countries and simultaneously optimizing generation investments and dispatch as well as utilization of transmission lines the model is used to evaluate the benefits of further line extensions between the european mainland and northern european countries we compute welfare gains and the distribution of these gains within a business as usual scenario up to 2030

invested interests the politics of national economic policies in a world of global finance capital moves more rapidly across national borders now than it has in at least fifty years and perhaps in history this article examines the effects of capital mobility on different groups in national societies and on the politics of economic policymaking it begins by emphasizing that while financial markets are highly integrated within the developed world many investments are still quite specific with respect to firm sector or location it then argues that contemporary levels of international capital mobility have a differential impact on socioeconomic groups over the long run increased capital mobility tends to favor owners of capital over other groups in the shorter run owners and workers in specific sectors in capital exporting countries bear much of the burden of adjusting to increased capital mobility these patterns can be expected to lead to political divisions about whether or not to encourage or increase international capital market integration the article then demonstrates that capital mobility also affects the politics of other economic policies most centrally it shifts debate toward the exchange rate as an intermediate or ultimate policy instrument in this context it tends to pit groups that favor exchange rate stability against groups that are more concerned about national monetary policy autonomy and therefore less concerned about exchange rate stability similarly it tends to drive a wedge between groups that favor an appreciated exchange rate and groups that favor a depreciated one these divisions have important implications for such economic policies as european monetary and currency union the dollar yen exchange rate and international macroeconomic policy coordination