an epec approach to the yearly maintenance scheduling of generating units this paper considers the yearly maintenance scheduling of generating units within a market environment each producer schedules its units maintenance periods to maximize its revenue using a bilevel approach the upper level problem of this bilevel model seeks maximum revenue and contains unit scheduling constraints while the lower level problems represent the market clearing process under different operating conditions this single producer maintenance problem can be recast as a mathematical program with equilibrium constraints mpec since the mpecs of all producers have to be considered simultaneously and the market clearing process is common to all of them the proposed formulation for maintenance scheduling is an equilibrium problem with equilibrium constraints epec corresponding to a multiple leader common follower game the solution of this epec is a set of equilibria in which none of the producers is able to increase its revenue unilaterally by changing the maintenance periods of its generating units

the demand for teacher characteristics in the market for child care evidence from a field experiment abstract this paper sheds light on two key issues regarding the demand for teacher characteristics in the market for center based child care first we study the extent to which teacher qualifications often considered important inputs to classroom quality are valued by providers during the hiring process we then examine the impact of state regulations on hiring decisions to do so a resume audit study was administered in which job seeker characteristics were randomly assigned to resumes that were submitted in response to real child care job postings in 14 u s cities our results indicate that center based providers may not hire the most qualified applicants for example we find that although providers have a strong preference for individuals with previous work experience in early childhood education ece those with more ece experience are less likely to receive an interview than those with less experience we also find that individuals with bachelor s degrees in ece are no more likely to receive an interview than their counterparts at the associate s level our analysis of state regulations shows that they strongly influence teacher hiring decisions we find that providers advertised job requirements are largely in compliance with the state standards for teachers experience and education in addition providers are substantially more likely to interview job seekers who meet these requirements given that most providers voluntarily exceed the state regulations a tentative conclusion is that such rules have a limited effect on child care supply and prices

oil and foreign exchange market tail dependence and risk spillovers for mena emerging and developed countries vmd decomposition based copulas abstract this paper examines the short and medium run dependence structures between oil and currency markets for mena other developing and developed countries using a novel multiresolution decomposition method namely the variational mode decomposition vmd along with a battery of time invariant and time varying symmetric and asymmetric copula functions further we assess the downside and upside short and medium run risk spillovers from oil to u s exchange rate returns and vice versa by computing the conditional value at risk covar risk measures before the copula estimations we apply the spillover index of diebold and yilmaz 2012 and network diagrams to identify and select the currencies that are the most significant net contributors or net receivers of returns from to the oil currency markets the copula results show strong evidence of time varying and high average tail dependence between oil returns and the fx markets which are net transmitters to oil for the short and medium time horizons on the other hand we find average and relatively low dynamic dependence between oil and the net receiver currencies regardless of the time horizons moreover there is evidence of up and down risk asymmetric systemic risks from oil to currencies and vice versa for some countries in the short and medium run horizons finally the risk spillovers are asymmetric over time and investment horizons these results have several important implications for hedging strategies and diversification benefits for oil and fx traders and institutional investors

does oil move equity prices a global view many studies indicate that oil price shocks have an adverse effect on real output and hence an adverse effect on corporate profits where oil is used as a key input the present study examines whether and to what extent the adverse effect of oil price shocks impacts stock market returns to this end we analyse 35 datastream global industry indices for the period from april 1983 to september 2005 our findings indicate that oil price rises have a negative impact on equity returns for all sectors except mining and oil and gas industries generally these results are consistent with economic theory and evidence provided by previous empirical studies little evidence of any asymmetry is detected in the oil price sensitivities in light of our findings we recommend that international portfolio investors consider hedging oil price risk

volatility spillovers between oil prices and stock sector returns implications for portfolio management abstract in this article we take a recent generalized var garch approach to examine the extent of volatility transmission between oil and stock markets in europe and the united states at the sector level the empirical model is advantageous in that it typically allows simultaneous shock transmission in the conditional returns and volatilities insofar as volatility transmission across oil and stock sector markets is a crucial element for portfolio designs and risk management we also analyze the optimal weights and hedge ratios for oil stock portfolio holdings with respect to the results our findings point to the existence of significant volatility spillover between oil and sector stock returns however the spillover is usually unidirectional from oil markets to stock markets in europe but bidirectional in the united states our back testing procedures finally suggest that taking the cross market volatility spillovers estimated from the var garch models often leads to diversification benefits and hedging effectiveness better than those of commonly used multivariate volatility models such as the ccc garch of bollerslev 1990 the diagonal bekk garch of engle and kroner 1995 and the dcc garch of engle 2002

extreme risk spillovers between crude oil and stock markets abstract this paper investigates the spillovers of extreme risks between crude oil and stock markets using daily data of the s p 500 stock index and west texas intermediate wti crude oil futures returns based on the method of granger causality in risk value at risk var is employed to measure market risk and a class of kernel based tests is used to detect negative and positive risk spillover effects empirical results reveal that there are significant risk spillovers between the two markets extreme movements past or current in one market may have a significant predictive power for those in the other market prior to the recent financial crisis there are positive risk spillovers from stock market to crude oil market and negative spillovers from crude oil market to stock market after the financial crisis bidirectional positive risk spillovers are strengthened markedly the risk spillovers may occur instantaneously and or with a long time delay both positive and negative risk spillover effects exhibit asymmetric correlations

representative evidence on lying costs abstract a central assumption in economics is that people misreport their private information if this is to their material benefit several recent models depart from this assumption and posit that some people do not lie or at least do not lie maximally these models invoke many different underlying motives including intrinsic lying costs altruism efficiency concerns or conditional cooperation to provide an empirically validated microfoundation for these models it is crucial to understand the relevance of the different potential motives we measure the extent of lying costs among a representative sample of the german population by calling them at home in our setup participants have a clear monetary incentive to misreport misreporting cannot be detected reputational concerns are negligible and altruism efficiency concerns or conditional cooperation cannot play a role yet we find that aggregate reporting behavior is close to the expected truthful distribution suggesting that lying costs are large and widespread further lab experiments show that this result is not driven by the mode of communication

modeling load recovery impact for demand response applications in this paper we develop a novel mathematical model to describe the localized economic impact of load recovery by electricity consumers following demand response dr event participation in this model termed securitization cost and benefit associated with an amount of load recovery change exponentially with time varying stochastic discount rates these volatile rates which can be estimated using the principle of brownian motion are further examined via case studies on the roy billinton test system a formal application of the proposed recovery model to the crucial task of global dr scheduling is then studied the study indicates that it is possible to optimize a dr schedule to cater for uncertainty in the subsequent load recovery

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 increasing complementarity between cognitive and social skills abstract data linking 1972 and 1992 adolescent skill endowments to adult outcomes reveal increasing complementarity between cognitive and social skills in fact previously noted growth in demand for cognitive skills affected only individuals with strong endowments of both social and cognitive skills these findings are corroborated using census and cps data matched with dictionary of occupational titles dot job task measures employment in and earnings premia to occupations requiring high levels of both cognitive and social skill grew substantially compared with occupations that require only one or neither type of skill and this emerging feature of the labor market has persisted into the new millennium

do employers use unemployment as a sorting criterion when hiring evidence from a field experiment the stigma associated with long term unemployment spells could create large inefficiencies in labor markets while the existing literature points toward large stigma effects it has proven difficult to estimate causal relationships using data from a field experiment we find that long term unemployment spells in the past do not matter for employers hiring decisions suggesting that subsequent work experience eliminates this negative signal nor do employers treat contemporary short term unemployment spells differently suggesting that they understand that worker firm matching takes time however employers attach a negative value to contemporary unemployment spells lasting at least nine months providing evidence of stigma effects

oil and the macroeconomy since world war ii all but one of the u s recessions since world war ii have been preceded typically with a lag of around three fourths of a year by a dramatic increase in the price of crude petroleum this does not mean that oil shocks caused these recessions evidence is presented however that even over the period 1948 72 this correlation is statistically significant and nonspurious supporting the proposition that oil shocks were a contributing factor in at least some of the u s recessions prior to 1972 by extension energy price increases may account for much of post opec macroeconomic performance

returns to skills around the world evidence from piaac abstract existing estimates of the labor market returns to human capital give a distorted picture of the role of skills across different economies international comparisons of earnings analyses rely almost exclusively on school attainment measures of human capital and evidence incorporating direct measures of cognitive skills is mostly restricted to early career workers in the united states analysis of the new piaac survey of adult skills over the full lifecycle in 23 countries shows that the focus on early career earnings leads to underestimating the lifetime returns to skills by about one quarter on average a one standard deviation increase in numeracy skills is associated with an 18 percent wage increase among prime age workers but this masks considerable heterogeneity across countries eight countries including all nordic countries have returns between 12 and 15 percent while six are above 21 percent with the largest return being 28 percent in the united states estimates are remarkably robust to different earnings and skill measures additional controls and various subgroups instrumental variable models that use skill variation stemming from school attainment parental education or compulsory schooling laws provide even higher estimates intriguingly returns to skills are systematically lower in countries with higher union density stricter employment protection and larger public sector shares

atheoretical macroeconometrics a critique abstract the spurious nature of the restrictions used to identify many macroeconometric models has led some researchers to advocate a style of econometric inquiry that is less dependent on prior theoretical restrictions of the sort that were central to the approach of the cowles commission this development which we call atheoretical macroeconometrics is summarized and evaluated in the current paper it is contrasted with an updated version of the cowles commission approach we conclude that while some of the exercises of atheoretical macroeconometrics are valid those that have attracted the most attention and appear the most innovative exogeneity testing impulse response analysis and policy analysis using estimated vector autoregressions are based on incorrect analysis

the dynamic effects of oil supply shocks on the us stock market returns of upstream oil and gas companies abstract a time varying parameter var model is used to examine the impact of structural oil supply shocks on the us real stock market return of oil and gas exploration and production companies the result shows that the impact response of the real return of the upstream stocks to a negative world non us oil supply shock increases substantially over recent years from an average value of 0 70 in 2006 to 6 16 during 2008 2010 with a spike of 6 81 in 2014q3 the endogenous effects of us oil supply shocks on the return play an important role in that the responses of the stock returns to a negative us oil supply shock are positive and persistent with an average value of 3 60 over time the time varying effects of oil supply shocks are heterogeneous the magnitudes of return responses are different among independents large proved reserve independents and integrated companies over time

oil price shocks and stock market returns evidence for some european countries abstract in this paper we examine the impact of oil price shocks on stock returns in 12 oil importing european economies using vector autoregressive var and vector error correction models vecm for the period 1973 02 2011 12 we propose an alternative oil price shock specification that takes into account both world oil production and world oil prices in order to disentangle oil supply and oil demand shocks we find that the response of the european real stock returns to an oil price shock may differ greatly depending on the underlying causes of the oil price change the results suggest the existence of a negative and significant impact of oil price changes on most european stock market returns furthermore we find that stock market returns are mostly driven by oil supply shocks

does the s p500 index lead the crude oil dynamics a complexity based approach abstract taking the complex property of nonlinear feedback connectivity into consideration the goal of this paper is to apprehend the interdependences between the financial and energy sectors our contribution is both theoretical and methodological we conduct a multivariate analysis employing nonlinear tools namely the partial transfer entropy and the asymmetric mackey glass causality test in particular we build a system comprising the petroleum complex crude oil gasoline and heating oil the s p500 index and the 1 month futures spot spread for crude oil by adopting a rolling window approach we observe a persistent lead lag relationship between the s p500 index and the market participants expectations for crude oil from 2004 to 2009 depending on the bubble period in the stock market it appears that the resulting coupling becomes subject to the deterioration of global economic activity induced by large common shocks

stock market volatility and business cycle evidence from linear and nonlinear causality tests this paper investigates the relationship between stock market volatility and the business cycle in four major economies namely the us canada japan and the uk we employ both linear and nonlinear bivariate causality tests and we further conduct a multivariate analysis to explore possible spillover effects across countries our results suggest that there is a bidirectional causal relationship between stock market volatility and the business cycle within each country and additionally reveal that the recent financial crisis plays an important role in this context finally we identify a significant impact of the us on the remaining markets

volatility spillovers among oil and stock markets in the us and saudi arabia in this article we use high frequency data and an identification via changes in volatility approach to assess the volatility spillovers among oil and the us and saudi arabian stock markets we doc

linkages between oil price shocks and stock returns revisited abstract in this paper we revisit the debate on the relationship between oil price shocks and stock market returns by replicating the quantile on quantile qq regression model for the us stock market in sim and zhou 2015 journal of banking and finance and extending it to 15 countries the classification of these countries as oil importers or oil exporters depends on their net position in crude oil trade our results indicate that the main finding by sim and zhou 2015 that large negative oil price shocks can bolster stock returns when markets are performing well is only partially supported by the three largest oil importers in our sample china japan and india during the period 1988 1 2007 12 however when extending the study to more recent data period 1988 1 2016 12 we find that china and india experience higher returns when markets perform well and there is a large positive oil price shock also large positive oil price shocks often lead to higher stock market returns when markets perform well for both oil exporting countries canada russia norway and moderately oil dependent countries such as malaysia philippines and thailand in most cases large negative oil price shocks depress further already poorly performing markets as in sim and zhou 2015 these findings highlight that the relationship between the distributions of oil price shocks and stock market returns is not stable over time in most countries studied furthermore the asymmetric effect between positive and negative oil price shocks observed in the us market by sim and zhou 2015 is less evident in most countries for both the baseline and extended periods

toward a new deal for saudi arabia oil or islamic stock market investment amid the ongoing national development programme of saudi arabia saudi vision 2030 a large trade openness plan to reduce saudi arabia s dependence on oil and to diversify its economy is announced

dynamic pricing design for demand response integration in power distribution networks this paper presents optimal pricing design for demand response dr integration in the distribution network in particular we study the energy scheduling problem for a load serving entity lse that serves two types of loads namely inflexible and flexible loads inflexible loads are charged under a regular pricing tariff while flexible loads enjoy a dynamic pricing tariff that ensures cost saving for them moreover flexible loads are assumed to be aggregated by several dr aggregators the interaction between the lse and its customers is formulated as a bilevel optimization problem where the lse is the leader and dr aggregators are the followers the optimal solution of this problem corresponds to the optimal pricing tariff for flexible loads the key advantage of the proposed model is that it can be readily implemented thanks to its compatibility with existing pricing structures in the retail market extensive numerical results show that the proposed approach provides a win win solution for both the lse and its customers

asymmetric effects of oil price shocks on stock returns evidence from a two stage markov regime switching approach abstractthe asymmetric effects of oil price shocks on stock returns have attracted the attention of many researchers in the past several decades most of these researchers studies however do not separate out the sources of oil price shocks when examining the asymmetric effects in this article we address this limitation using a two stage markov regime switching approach our results indicate that oil supply and demand shocks have a null or minimal impact on stock returns in a low volatility regime and a statistically significant impact in a high volatility regime we observe that oil demand shocks affect stock returns significantly more than oil supply shocks a positive aggregate demand shock significantly increases stock returns whereas a positive oil specific demand shock markedly decreases stock returns these results have important implications for policymakers and investors

skills signals and employability an experimental investigation abstract because most skills of labor market entrants are not directly observed by employers individuals acquire skill signals to study which signals are valued by employers we randomize several skill signals on resumes of fictitious applicants among which we ask a large representative sample of german human resource managers to choose we find that signals in both studied domains cognitive and social skills have significant effects on being invited for a job interview consistent with their relevance expectedness and credibility different signals are effective for apprenticeship applicants and college graduates while gpas and social skills are significant for both genders females are particularly rewarded for it and language skills older hr managers value school grades less and other signals more hr managers in larger firms value college grades more

oil price shocks and stock markets in the u s and 13 european countries abstract oil price shocks have a statistically significant impact on real stock returns contemporaneously and or within the following month in the u s and 13 european countries over 1986 1 2005 12 norway as an oil exporter shows a statistically significantly positive response of real stock returns to an oil price increase the median result from variance decomposition analysis is that oil price shocks account for a statistically significant 6 of the volatility in real stock returns for many european countries but not for the u s increased volatility of oil prices significantly depresses real stock returns the contribution of oil price shocks to variability in real stock returns in the u s and most other countries is greater than that of interest rate an increase in real oil price is associated with a significant increase in the short term interest rate in the u s and eight out of 13 european countries within one or two months counter to findings for the u s and for norway there is little evidence of asymmetric effects on real stock returns of positive and negative oil price shocks for oil importing european countries

this is what happened to the oil price macroeconomy relationship abstract many of the quarterly oil price increases observed since 1985 are corrections to even bigger oil price decreases the previous quarter when one looks at the net increase in oil prices over the year recent data are consistent with the historical correlation between oil shocks and recessions

duration dependence and labor market conditions evidence from a field experiment this article studies the role of employer behavior in generating negative duration dependence the adverse effect of a longer unemployment spell by sending fictitious resumes to real job postings in 100 u s cities our results indicate that the likelihood of receiving a callback for an interview significantly decreases with the length of a worker s unemployment spell with the majority of this decline occurring during the first eight months we explore how this effect varies with local labor market conditions and find that duration de pendence is stronger when the local labor market is tighter this result is consistent with the prediction of a broad class of screening models in which employers use the unemployment spell length as a signal of unobserved productivity and recognize that this signal is less informative in weak labor markets jel code j64

crude oil and stock markets causal relationships in tails abstract this paper considers the causal relationships between wti and dubai crude oil returns and five stock index returns s p 500 nikkei hang seng shanghai and kospi within the quantile causality framework by using daily data for a period from january 1 1996 to october 12 2012 the quantile causality test is useful for a comprehensive understanding of the causal relationship between two returns the test reveals several noteworthy results first although wti returns are not closely related to asian countries some financial markets such as nikkei and hang seng granger cause wti returns second the significance of causality from one market to another derives only from lower and upper levels of quantiles except for the case of causality from nikkei to wti returns third all stock index returns granger cause dubai crude oil returns over almost all quantile levels except for shanghai returns fourth dubai crude oil returns granger cause all asian stock index returns except for s p 500 returns finally the results indicate asymmetric causality from dubai crude oil returns to shanghai returns and kospi returns to dubai crude oil returns

balancing energy security priorities portfolio optimization approach to oil imports the notion of energy security in most interpretations includes the physical supply and price affordability components making financial risks a crucial part of energy security strategies mainstrea

how does your kindergarten classroom affect your earnings evidence from project star in project star 11 571 students in tennessee and their teachers were randomly assigned to classrooms within their schools from kindergarten to third grade this article evaluates the long term impacts of star by linking the experimental data to administrative records we first demonstrate that kindergarten test scores are highly correlated with outcomes such as earnings at age 27 college attendance home ownership and retirement savings we then document four sets of experimental impacts first students in small classes are significantly more likely to attend college and exhibit improvements on other outcomes class size does not have a significant effect on earnings at age 27 but this effect is imprecisely estimated second students who had a more experienced teacher in kindergarten have higher earnings third an analysis of variance reveals significant classroom effects on earnings students who were randomly assigned to higher quality classrooms in grades k 3 as measured by classmates end of class test scores have higher earnings college attendance rates and other outcomes finally the effects of class quality fade out on test scores in later grades but gains in noncognitive measures persist

crude oil and stock markets stability instability and bubbles abstract we analyze the long run relationship between the world price of crude oil and international stock markets over 1971 1 2008 3 using a cointegrated vector error correction model with additional regressors allowing for endogenously identified breaks in the cointegrating and error correction matrices we find evidence for breaks after 1980 5 1988 1 and 1999 9 there is a clear long run relationship between these series for six oecd countries for 1971 1 1980 5 and 1988 2 1999 9 suggesting that stock market indices respond negatively to increases in the oil price in the long run during 1980 6 1988 1 we find relationships that are not statistically significantly different from either zero or from the relationships of the previous period the expected negative long run relationship appears to disintegrate after 1999 9 this finding supports a conjecture of change in the relationship between real oil price and real stock prices in the last decade compared to earlier years which may suggest the presence of several stock market bubbles and or oil price bubbles since the turn of the century

forecasting with medium and large bayesian vars this paper is motivated by the recent interest in the use of bayesian vars for forecasting even in cases where the number of dependent variables is large in such cases factor methods have been traditionally used but recent work using a particular prior suggests that bayesian var methods can forecast better in this paper we consider a range of alternative priors which have been used with small vars discuss the issues which arise when they are used with medium and large vars and examine their forecast performance using a us macroeconomic dataset containing 168 variables we find that bayesian vars do tend to forecast better than factor methods and provide an extensive comparison of the strengths and weaknesses of various approaches typically we find that the simple minnesota prior forecasts well in medium and large vars which makes this prior attractive relative to computationally more demanding alternatives our empirical results show the importance of using forecast metrics based on the entire predictive density instead of relying solely on those based on point forecasts

correlations and volatility spillovers between oil prices and the stock prices of clean energy and technology companies abstract in this paper multivariate garch models are used to model conditional correlations and to analyze the volatility spillovers between oil prices and the stock prices of clean energy companies and technology companies four different multivariate garch models bekk diagonal constant conditional correlation and dynamic conditional correlation are compared and contrasted the dynamic conditional correlation model is found to fit the data the best and generates results showing that the stock prices of clean energy companies correlate more highly with technology stock prices than with oil prices on average a 1 long position in clean energy companies can be hedged for 20 cents with a short position in the crude oil futures market

ban the box criminal records and racial discrimination a field experiment ban the box btb policies restrict employers from asking about applicants criminal histories on job applications and are often presented as a means of reducing unemployment among black men who disproportionately have criminal records however withholding information about criminal records could risk encouraging racial discrimination employers may make assumptions about criminality based on the applicant s race to investigate btb s effects we sent approximately 15 000 online job applications on behalf of fictitious young male applicants to employers in new jersey and new york city before and after the adoption of btb policies these applications varied whether the applicant had a distinctly black or distinctly white name and the felony conviction status of the applicant we confirm that criminal records are a major barrier to employment employers that asked about criminal records were 63 more likely to call applicants with no record however our results support the concern that btb policies encourage racial discrimination the black white gap in callbacks grew dramatically at companies that removed the box after the policy went into effect before btb white applicants to employers with the box received 7 more callbacks than similar black applicants but btb increased this gap to 43 we believe that the best interpretation of these results is that employers are relying on exaggerated impressions of real world racial differences in felony conviction rates

oil prices stock markets and portfolio investment evidence from sector analysis in europe over the last decade this article extends the understanding of oil stock market relationships over the last turbulent decade unlike previous empirical investigations which have largely focused on broad based market indices national and or regional indices we examine short term linkages in the aggregate as well as sector by sector levels in europe using different econometric techniques our main findings suggest that the reactions of stock returns to oil price changes differ greatly depending on the activity sector in the out of sample analysis we show that introducing oil asset into a diversified portfolio of stocks allows to significantly improve its risk return characteristics

equilibria in an oligopolistic electricity pool with stepwise offer curves we study the equilibria reached by strategic producers in a pool based network constrained electricity market the behavior of each producer is modeled by a mathematical program with equilibrium constraints mpec whose objective is maximizing profit and whose complementarity constraints describe market clearing the joint solution of all these mpecs constitutes an equilibrium problem with equilibrium constraints epec the equilibria associated with the epec are analyzed by solving the strong stationarity conditions of all mpecs which can be linearized without approximation by mixed integer linear programming milp techniques the resulting mixed integer linear conditions can be reformulated as an optimization problem that allows establishing diverse objectives to differentiate among alternative equilibria

oil shocks and stock volatility new evidence via a bayesian graph based var approach abstractthis article examines the temporal dependence between three oil shocks and realized volatility in the stock markets of g20 countries between 1994 and 2019 by applying a novel graphical b

coping with change international differences in the returns to skills international data from the piaac survey allow estimation of comparable labor market returns to skills for 32 countries returns to skills are larger in faster growing economies consistent with the hypothesis that skills are particularly important for adaptation to economic change

a bilevel approach to operational decision making of a distribution company in competitive environments this paper presents a model for operational decision making of a distribution company disco with distributed generation dg and interruptible loads il in a competitive market the disco objective modeled through the upper level problem is to minimize the cost of market purchases and dg unit dispatch while taking into account the responses of the other discos this upper level problem is constrained by a lower level market clearing problem whose objective corresponds to maximization of social welfare such a setting results in a multi disco equilibrium problem formulated as an equilibrium problem with equilibrium constraints epec by combining the optimality conditions of all upper level problems using a nonlinear approach the epec problem is reformulated as a single nonlinear optimization model which is simultaneously solved for all discos the proposed approach is applied to an ac model of a power system to account for voltage and reactive power constraints of the transmission and distribution networks numerical examples based on two test systems are presented to illustrate the application of the proposed method

strategic generation investment using a complementarity approach this paper provides a methodology to assist a strategic producer in making informed decisions on generation investment a single target year is considered with demand variations modeled through blocks the strategic behavior of the producer is represented through a bilevel model the upper level considers both investment decisions and strategic production actions and the lower level corresponds to market clearing prices are obtained as dual variables of power balance equations rival uncertainties on offering and investment are characterized through scenarios the resulting model is a large scale mixed integer lp problem solvable using currently available branch and cut techniques results pertaining to an illustrative example and a case study are reported and discussed

were there regime switches in u s monetary policy working paper 2004 14 june 2004 abstract a multivariate model identifying monetary policy and allowing for simultaneity and regime switching in coefficients and variances is confronted with u s data since 1959 the best fit is with a model that allows time variation in structural disturbance variances only among models that also allow for changes in equation coefficients the best fit is for a model that allows coefficients to change only in the monetary policy rule that model allows switching among three main regimes and one rarely and briefly occurring regime the three main regimes correspond roughly to periods when most observers believe that monetary policy actually differed and the differences in policy behavior are substantively interesting though statistically ill determined the estimates imply monetary targeting was central in the early 80s but was also important sporadically in the 70s the changes in regime were essential neither to the rise in inflation in the 70s nor to its decline in the 80s jel classification e52 e47 c53 key words counterfactuals lucas critique policy rule monetary targeting simultaneity volatility model comparison i the debate over monetary policy change in an influential paper clarida gali and gertler 2000 cgg presented evidence that us monetary policy changed between the 1970 s and the 1980 s indeed that in the 70 s it was drastically worse they found that the policy rule apparently followed in the 70 s was one that when embedded in most stochastic general equilibrium models would imply non uniqueness of the equilibrium and hence vulnerability of the economy to sunspot fluctuations of arbitrarily large size their estimated policy rule for the later period on the other hand eliminated this indeterminacy these results are a possible explanation of the volatile and rising inflation of the 70 s and of its subsequent decline the cgg analysis has two important weaknesses one is that it fails to account for stochastic volatility us macroeconomic variables and particularly the federal funds rate have gone through periods of tranquility and of agitation with forecast error variances varying greatly from period to period ignoring such variation does not lead to inconsistent estimates of model parameters when the forecasting equations themselves are constant but it strongly biases toward a finding of changed parameters tests of the stability of the forecasting equations the other weakness is that the cgg analysis rests on powerful and implausible identifying assumptions they require that we accept that the response of the monetary authority to expected future inflation and output does not depend on the recent history of inflation money growth or output it is hard to understand why this should be so especially in the 70 s when monetarism was a prominent theme in policy debates congress was requiring reports from the fed of projected time paths of monetary aggregates and financial markets were reacting sensitively to weekly money supply numbers the requirement for existence and uniqueness of equilibrium in dynamic models is that the monetary policy rule show a more than unit response of interest rates to the sum of the logs of all nominal variables that appear on the right hand side of the reaction function if we force a particular measure of expected future inflation to proxy for all the nominal variables that actually appear independently in the reaction function we are bound to get distorted conclusions on the one hand because expected future inflation will be a noisy measure of the full set of nominal influences on policy we might get downward bias in our estimates from the usual errorsin variables effect on the other hand to the extent that expected future inflation like most expected future values shows less variation than current nominal variables we could find a mistaken scaling up of coefficients

the value of postsecondary credentials in the labor market an experimental study we study employers perceptions of the value of postsecondary degrees using a field experiment we randomly assign the sector and selectivity of institutions to fictitious resumes and apply to real vacancy postings for business and health jobs on a large online job board we find that a business bachelor s degree from a for profit online institution is 22 percent less likely to receive a callback than one from a nonselective public institution in applications to health jobs we find that for profit credentials receive fewer callbacks unless the job requires an external quality indicator such as an occupational license jel i23 i26 j24 j44 j63 m51

the effect of oil prices on stock prices fresh evidence from asymmetric causality tests abstractthis article investigates the causal impact of oil prices on stock prices in each g7 market as well as in the world market an asymmetric causality test developed by hatemi j is used for this purpose since the underlying data appears to be non normal with time varying volatility we use bootstrap simulations with leverage adjustments in order to produce more reliable critical values than the asymptotic ones based on symmetric causality tests we find no causal effect of oil prices on the stock prices of the world market or any of the g7 countries however when we apply an asymmetric causality test we find that increasing oil prices cause stock prices to rise in the world the u s and japan while decreasing oil prices cause stock prices to fall in germany this may imply that the world the u s and japanese stock markets consider increases in oil prices as an indicator of good news as this may mean that there is an increase in oil demand due to an expected growth in the economy while the germ

experimental research on labor market discrimination understanding whether labor market discrimination explains inferior labor market outcomes for many groups has drawn the attention of labor economists for decades at least since the publication of gary becker s the economics of discrimination in 1957 the decades of research on discrimination in labor markets began with a regression based decomposition approach asking whether raw wage or earnings differences between groups which might constitute prima facie evidence of discrimination were in fact attributable to other productivity related factors subsequent research responding in large part to limitations of the regression based approach moved on to other approaches such as using firm level data to estimate both marginal productivity and wage differentials in recent years however there has been substantial growth in experimental research on labor market discrimination although the earliest experiments were done decades ago some experimental research on labor market discrimination takes place in the lab but far more of it is done in the field which makes this particular area of experimental research unique relative to the explosion of experimental economic research more generally this paper surveys the full range of experimental literature on labor market discrimination places it in the context of the broader research literature on labor market discrimination discusses the experimental literature from many different perspectives empirical theoretical and policy and reviews both what this literature has taught us thus far and what remains to be done

a stochastic framework for short term operation of a distribution company this paper presents a stochastic framework for short term operation of a distribution company disco the proposed framework optimizes disco s operational decisions in two hierarchical stages the first stage called day ahead operation stage daos deals with the operational decisions on purchases from the day ahead market and commitment of distributed generation dg units the objective of this stage is to minimize the expected operating cost while the financial risk exposed by uncertain real time prices and loads is restricted to a given level the model associated with this stage is based on the mixed integer programming mip format the second stage named real time operation stage rtos deals with disco s activities in real time in rtos decisions are made on real time market transactions dispatch of online dgs and invocation of load curtailments lcs such that the expected operating cost is minimized this stage is formulated as a nonlinear programming nlp problem to investigate the effectiveness of the developed framework it is applied to a typical finnish 20 kv urban distribution network

the growing importance of social skills in the labor market the labor market increasingly rewards social skills between 1980 and 2012 jobs requiring high levels of social interaction grew by nearly 12 percentage points as a share of the u s labor force math intensive but less social jobs including many stem occupations shrank by 3 3 percentage points over the same period employment and wage growth were particularly strong for jobs requiring high levels of both math skill and social skills to understand these patterns i develop a model of team production where workers trade tasks to exploit their comparative advantage in the model social skills reduce coordination costs allowing workers to specialize and work together more efficiently the model generates predictions about sorting and the relative returns to skill across occupations which i investigate using data from the nlsy79 and the nlsy97 using a comparable set of skill measures and covariates across survey waves i find that the labor market return to social skills was much greater in the 2000s than in the mid 1980s and 1990s

responses of international stock markets to oil price surges a regime switching perspective we propose an enhanced regime switching model to investigate the relationships between oil price surges and stock market cycles in five oil dependent countries our model accounts for the joint effects of the west texas intermediate wti and brent oil markets and simultaneously captures asymmetry volatility persistence and regime shifts contained in the underlying financial data we find that stock market returns strongly exhibit a regime switching behaviour but they react differently to the increases in the price of oil more precisely the conditional volatility of studied stock markets during the bear market phases is found to be less affected by oil price surges than during the bull market phases whether the effects of oil shocks are positive or negative depends greatly on the degree of reliance on imported oil the share of the cost of oil in the national income and the degree of improvement in energy efficiency of a given country finally the relatively opposite effects of the wti and brent oil

education and labor market discrimination using a model of statistical discrimination and educational sorting we explain why blacks get more education than whites of similar cognitive ability and we explore how the armed forces qualification test afqt wages and education are related the model suggests that one should control for both afqt and education when compar ing the earnings of blacks and whites in which case a substantial black white wage differential emerges we reject the hypothesis that differences in school quality between blacks and whites explain the wage and education differentials our findings support the view that some of the black white wage differential reflects the operation of the

do structural oil market shocks affect stock prices abstract this paper investigates how explicit structural shocks that characterize the endogenous character of oil price changes affect stock market returns in a sample of eight countries australia canada france germany italy japan the united kingdom and the united states for each country the analysis proceeds in two steps first modifying the procedure of kilian kilian l forthcoming not all oil price shocks are alike disentangling demand and supply shocks in the crude oil market american economic review we employ a vector error correction or vector autoregressive model to decompose oil price changes into three components oil supply shocks global aggregate demand shocks and global oil demand shocks the last component relates to specific idiosyncratic features of the oil market such as changes in the precautionary demand concerning the uncertainty about the availability of future oil supplies second recovering the oil supply shocks global aggregate demand shocks and global oil demand shocks from the first analysis we then employ a vector autoregressive model to determine the effects of these structural shocks on the stock market returns in our sample of eight countries we find that international stock market returns do not respond in a large way to oil market shocks that is the significant effects that exist prove small in magnitude

oil price movements and stock markets revisited a case of sector stock price indexes in the g 7 countries abstract applying sector stock prices and oil prices in 1991 01 2009 05 from the g7 countries we find oil price shocks do not significantly impact the composite index in each country however stock price changes in germany the uk and the us were found to lead oil price changes as for the interaction between oil price changes and sector stock price changes we find short run negative causal relationships 4 of 7 sector index returns were impacted by oil price changes in germany 2 in the us and 1 in france in particular stock returns of information technology and consumer staples sectors were found to be impacted most by oil price shocks followed by financial utilities and transportation sectors in terms of causality from sector stock price changes to oil price changes we find stock price changes lead oil price changes in 8 of 9 sectors in germany most in the g7 countries followed by the uk italy france canada and the us no such a causal relationship however is found for japan with respect to specific sectors stock price changes in consumer staples and materials sectors were impacted most significantly by oil price changes followed by transportation financial energy health care industrials utilities information technology and telecommunication sectors with the exception of consumer discretionary sector in addition short term stock price changes are found to lead positively oil price changes

determinants of callbacks to job applications an audit study abstract we summarize findings from an audit study investigating how unemployment duration age and holding a low level interim job affect the likelihood that experienced college educated females applying for administrative support jobs receive a callback from potential employers the results show no relationship between callback rates and unemployment duration in contrast workers age 50 and older and workers with an interim job are significantly less likely to receive callbacks we also summarize disparate findings in the growing literature of resume based audit studies of career histories and discuss avenues in which the literature could achieve results that are more comparable and externally valid

oil prices and mena stock markets new evidence from nonlinear and asymmetric causalities during and after the crisis period this article investigates the potential of nonlinear causal relationships between world oil prices and stock markets in middle east and north africa mena countries during a black swan period that is characterized by rarity and devastating impacts our study is carried out using the daily data for 11 mena countries over the period from 2 july 2007 to 27 august 2012 by using the nonlinear and asymmetric causality test of kyrtsou and labys 2006 we mainly find that i the oil prices and mena stock markets interact in a nonlinear manner ii the signs of changes in the causing variables are important for detecting the true causality links between the variables and iii the nonlinear causality is more pronounced in the case of the brent than west texas intermediate oil prices