short sales are almost instantaneously bad news evidence from the australian stock exchange this paper investigates the market reaction to short sales on an intraday basis in a market setting where short sales are transparent immediately following execution we find a mean reassessment of stock value following short sales of up to 0 20 percent with adverse information impounded within fifteen minutes or twenty trades short sales executed near the end of the financial year and those related to arbitrage and hedging activities are associated with a smaller price reaction trades near information events precipitate larger price reactions the evidence is generally weaker for short sales executed using limit orders relative to market orders this article analyzes the intraday price behavior surrounding short sales executed using market and limit orders within a transparent setting a number of recent studies have focused on daily or monthly stock price behavior surrounding short selling activity in u s markets e g senchack and starks 1993 figlewski and webb 1993 conrad 1994 hanley and seyhun 1994 asquith and meulbroek 1996 and dechow et al 1997 this research has been motivated by the continued interest of market regulators i n short selling activity and the controversy surrounding the desirability restrictions and disclosure requirements related to short selling see janvey 1992 and ramsay 1993 in particular several studies such as that by figlewski and webb 1993 have examined the relationship between short positions and subsequent abnormal returns without finding a strong relationship asquith and meulbroek 1996 in contrast focus on firms with large short positions and find a strong and consistent relationship dechow et al 1997 find a correlation between short selling strategies and strategies based on fundamental analysis these results are consistent with short sellers being able to identify

distribution locational marginal pricing for optimal electric vehicle charging management this paper presents an integrated distribution locational marginal pricing dlmp method designed to alleviate congestion induced by electric vehicle ev loads in future power systems in the proposed approach the distribution system operator dso determines distribution locational marginal prices dlmps by solving the social welfare optimization of the electric distribution system which considers ev aggregators as price takers in the local dso market and demand price elasticity nonlinear optimization has been used to solve the social welfare optimization problem in order to obtain the dlmps the efficacy of the proposed approach was demonstrated by using the bus 4 distribution system of the roy billinton test system rbts and danish driving data the case study results show that the integrated dlmp methodology can successfully alleviate the congestion caused by ev loads it is also shown that the socially optimal charging schedule can be implemented through a decentralized mechanism where loads respond autonomously to the posted dlmps by maximizing their individual net surplus

day of the week effects and asset returns the number of empirical studies using daily stock returns is rapidly increasing researchers generally assume that the distribution of stock returns is identical for all days of the week a convenient statistical assumption but not a necessary condition of market equilibrium nevertheless there are reasons to suspect that the distribution of returns may vary according to the day of the week the most obvious is the impact of weekends on monday s return since monday s return is calculated over three instead of one calender day the mean and variance may well be higher on monday compared with any other daily return perhaps three times as large previous research has examined the daily distribution of stock returns for a monday effect while fama 1965 does not compare daily mean returns he does report that monday s variance is about 20o greater than other daily returns with a traditional distributional assumption regarding the returns on a financial asset specifies that the expected returns are identical for all days of the week contrary to this plausible assumption this paper discovers that the expected returns on common stocks and treasury bills are not constant across days of the week the most notable evidence is for monday s returns where the mean is unusually low or even negative several explanations of the results are investigated but none proves satisfactory aside from documenting significant day of the week effects the implications of the results for tests of market efficiency are examined while market adjusted returns continue to exhibit day of the week effects these effects are no longer concentrated on monday during the last year we have had many conversations with our colleagues throughout the professions we are particularly thankful to the participants at sessions of the western and american finance associations where preliminary versions of this paper were presented special thanks are due to gene fama gailen hite jon ingersoll robert jarrow merton miller clifford smith and rex thompson the expert research assistance of frank rabinovitch and youngsup yun is gratefully acknowledged 1 the list of papers using daily stock returns is too long to name recent examples include charest 1978 dodd 1980 banz 1981 and reinganum 1981

an equilibrium model of asset trading with sequential information arrival in an effort to better understand the dynamic market price adjustment process this paper develops a model which describes the impact of new information on a financial market the primary emphasis is on the price change volume relationship in the presence of a margin requirement we find that the margin requirement significantly affects the relation of price change to volume furthermore this relationship is shown to be affected by the number of investors in the market the degree of information dissemination differences in interpretation of information and the implicit cost of the margin requirement

on walrasian equilibrium for pool based electricity markets we present a single time period decentralized electricity market clearing model that includes reactive power and demand responsiveness in addition to the more common framework of generation side competition for the real power commodity the approach allows self interested agents namely producers and consumers independently to maximize their individual surpluses subject to prices this is consistent with the very notion of a competitive market as defined in equilibrium theory an auctioneer computes equilibrium prices that achieve power balance at every network node as required by kirchhoff s laws the overall scheme is justified by duality theory for which there is a rich theoretical support and convergence is achieved using a newton price updating algorithm

immigration quotas and skill upgrading a reason why immigration policy is such a contended issue is that often immigrants end up obtaining the right to vote and hence may affect future policies this paper offers a dynamic general equilibrium model of immigration policy in each period a heterogeneously skilled population chooses an immigration policy by majority vote voters anticipate that immigration affects the skill premium and the skill composition of the electorate the main insight is the existence of a trade off between skill complementary immigration and the resulting shift in political power i argue that a reasonably parameterized version of the model is consistent with the main features of us immigration

short sale restrictions and market reaction to short interest announcements according to the diamond verrecchia hypothesis if increases in short interest are correlated with information that is not yet public they should precipitate a price adjustment stocks with unexpected increases in short interest are found to generate statistically significant but small negative abnormal returns for a short period around the announcement date when the sample is divided into stocks with and without tradable options nonoptioned stocks closely mimic these results but the optioned stocks do not in a cross sectional analysis of individual firms the short term negative abnormal returns are found to be 1 more negative the higher the degree of unexpected short interest and 2 less negative if the firm has tradable options

capital asset prices with and without negative holdings prize lecture to the memory of alfred nobel december 7 1990 this abstract was borrowed from another version of this item

exploitation of electric drive vehicles in electricity markets the paper presents the optimization algorithm which may eventually be used by electric energy suppliers to coordinate charging and discharging of electric drive vehicles edvs exploited in electricity markets the research is focused on a day ahead market and a provision of system regulation in an ancillary service market the proposed optimization minimizes the charging costs that can be partly compensated with profits obtained from participation in the energy markets due to the stochastic nature of transportation patterns the monte carlo simulation is applied to model uncertainties presented by numerous scenarios to reduce the problem complexity the simulated driving patterns are not individually considered in the optimization but clustered into fleets using the gams scenred tool uncertainties of energy requirements in the market and energy prices are presented by statistical central moments that are further considered in hong s 2 point 1 estimation method in order to define points considered in the optimization finally each energy supplier has to offer competitive energy prices to edv users for transportation due to uncertainties the final prices cannot be deterministically calculated thus the paper proposes the risk based approach applying value at risk case studies illustrate the application of the proposed optimization in achieving competitive prices for edv users

day of the week and intraday effects in stock returns abstract this study examines day of the week effects using hourly values of the dow jones industrial average we find that over the 1963 1983 period the weekend effect has sifted from characterizing active trading on monday to characterizing the non trading weekend over the early part of our sample period negative returns characterize each hour of trading on monday while the return from friday close to monday open is positive in the most recent subperiod monday average hourly returns after noon are all positive and the weekend effect is due to negative average returns from friday close to monday open

the impact of short selling on the price volume relationship evidence from hong kong this paper considers the relationship between traded volume and volatility allowing for the impact of short sales the evidence supports a nonlinear bidirectional relationship between volume and volatility short selling is found to have a significant impact on this relationship and our results suggest i that the hong kong market displays greater volatility following a period of short selling and ii that asymmetric responses to positive and negative innovations to returns appear to be exacerbated by short selling

earnings announcements stock price adjustment and the existence of option markets this paper employs a new approach to study the effects of option trading on the behavior of underlying stock prices extant research compares distributional properties of the stock price at two points in time divided by an event in the option market that might affect price behavior as an alternative we examine the stock price adjustment to the release of quarterly earnings using samples of firms with and without listed options we find the two samples exhibit different adjustment processes with the nonoption firms requiring substantially more time to adjust since the advent of organized stock option trading the investment community

the information content of short interest a natural experiment an increase in the cost of selling short should increase the bearish information content of short interest announcements by driving relatively uninformed short sellers out of the market we extend the diamond and verrecchia 1987 model to include short selling against the box and test the extended model using a natural experiment based around the taxpayer relief act of 1997 tra97 tra97 made short selling more costly for those shorting against the box consistent with the implications of our extended model this increase in short selling costs strengthens the negative relationship between short interest and subsequent stock price performance post tra97

decentralized participation of flexible demand in electricity markets part ii application with electric vehicles and heat pump systems realizing the significant demand flexibility potential in deregulated power systems requires its suitable integration in electricity markets part i of this work has presented the theoretical algorithmic and implementation aspects of a novel pool market mechanism achieving this goal by combining the advantages of centralized mechanisms and dynamic pricing schemes based on lagrangian relaxation lr principles part ii demonstrates the applicability of the mechanism considering two reschedulable demand technologies with significant potential namely electric vehicles with flexible charging capability and electric heat pump systems accompanied by heat storage for space heating the price response sub problems of these technologies are formulated including detailed models of their operational properties suitable case studies on a model of the u k system are examined in order to validate the properties of the proposed mechanism and illustrate and analyze the benefits associated with the market participation of the considered technologies

on corporate governance a study of proxy contests abstract this paper examines a sample of firms experiencing proxy contests for seats on their board of directors dissident shareholders usually fail to obtain a majority of board seats nevertheless they capture some seats via mechanisms such as cumulative voting in over half of the sample contests regardless of proxy contest outcome positive and statistically significant share price performance is associated with the contest that finding is predicted by the standard economic analysis of proxy contests in which the challenges benefit shareholders by improving corporate performance the finding runs counter to the claim of berle 1962 that the economists view of proxy contests is a wholly imaginary picture a portion of the positive share price changes taking place in the early stages of some proxy contests is not permanent however and as suggested by manne 1962 is at least partially attributable to temporary increases in the market value of the vote attached to corporate shares

volatility of power grids under real time pricing the paper proposes a framework for modeling and analysis of the dynamics of supply demand and clearing prices in power systems with real time retail pricing and information asymmetry characterized by passing on the real time wholesale electricity prices to the end consumers real time pricing creates a closed loop feedback system between the physical layer and the market layer of the system in the absence of a carefully designed control law such direct feedback can increase sensitivity and lower the system s robustness to uncertainty in demand and generation it is shown that price volatility can be characterized in terms of the system s maximal relative price elasticity defined as the maximal ratio of the generalized price elasticity of consumers to that of the producers as this ratio increases the system may become more volatile since new demand response technologies increase the price elasticity of demand and since increased penetration of distributed generation can also increase the uncertainty in price based demand response the theoretical findings suggest that the architecture under examination can potentially lead to increased volatility this study highlights the need for assessing architecture systematically and in advance in order to optimally strike the trade offs between volatility robustness and performance metrics such as economic efficiency and environmental efficiency

short selling and price discovery in corporate bonds we show short selling in corporate bonds forecasts future bond returns short selling predicts bond returns where private information is more likely in high yield bonds particularly after lehman brothers collapse of 2008 short selling predicts returns following both high and low past bond returns this together with short selling increasing following past buying order imbalances suggests short sellers trade against price pressures as well as trade on information short selling predicts bond returns both in the individual bonds that are shorted and in other bonds by the same issuer past stock returns and short selling in stocks predict bond returns but do not eliminate bond short selling predicting bond returns bond short selling does not predict the issuer s stock returns these results show bond short sellers contribute to efficient bond prices and that short sellers information flows from stocks to bonds but not from bonds to stocks

decentralized participation of flexible demand in electricity markets part i market mechanism in the deregulated power systems setting the realization of the significant demand flexibility potential should be coupled with its integration in electricity markets centralized market mechanisms raise communication computational and privacy issues while existing dynamic pricing schemes fail to realize the actual value of demand flexibility in this two part paper a novel day ahead pool market mechanism is proposed combining the solution optimality of centralized mechanisms with the decentralized demand participation structure of dynamic pricing schemes and based on lagrangian relaxation lr principles part i presents the theoretical background algorithmic approaches and suitable examples to address challenges associated with the application of the mechanism and provides an implementation framework non convexities in reschedulable demand participants price response and their impacts on the ability of the basic lr structure to reach feasible market clearing solutions are identified and a simple yet effective lr heuristic method is developed to produce both feasible and high quality solutions by limiting the concentrated shift of reschedulable demand to the same low priced time periods

short sales and speed of price adjustment evidence from the hong kong stock market abstract we present empirical evidence that short sales contribute to market efficiency by increasing the speed of price adjustment to not only private public firm specific information but also market wide information shortable stocks are characterized by weaker trade continuity and stronger quote reversals they adjust faster to new information than non shortable counterparts these findings remain robust even in an up market condition in which short sales are not binding the amount of information incorporated in each trade is also significantly higher for shortable than non shortable stocks in both up and down market conditions after controlling for firm size trading volume liquidity price and option trading short sales stand out as one of the significant factors that speed up the price adjustment

assessment of the cost associated with wind generation prediction errors in a liberalized electricity market in this paper a probabilistic methodology for estimating the energy costs in the market for wind generators associated with wind prediction errors is proposed generators must buy or sell energy production deviations due to prediction errors when they bid in day ahead or hour ahead energy markets the prediction error is modeled through a probability density function that represents the accuracy of the prediction model production hourly energy deviations and their associated trading costs are then calculated three study cases based on real wind power installations in spain are analyzed the three study cases show that the error prediction costs can reach as much as 10 of the total generator energy incomes

the informational effects of restrictions on short sales some empirical evidence in a world of heterogeneous investors a competitive financial market has two major functions first it is the mechanism by which ownership of the existing supply of risky assets is distributed among investors this is the role which is analyzed in detail by the standard capital asset pricing model capm and its many extensions the second important market function is to aggregate the diverse information held by different investors into a single price most versions of the capm eliminate the information aggregation function by assuming that investors hold homogeneous beliefs with respect to the probability distribution of asset returns exceptions which deal with some aspects of the problem are lintner 7 grossman 4 grossman and stiglitz 5 and figlewski 1 3

short interest explanations and tests cross sectional and time series tests are performed to explain levels and changes in short interest explanatory variables and tests are chosen based on tax arbitrage and speculative reasons for going short short interest is found to follow a seasonal pattern that is weakly consistent with tax based trading stocks with high betas and the existence of convertible securities or options tend to have higher levels of short interest which is con sistent with arbitrage efforts for firms with traded options there is a positive association between the month to month changes in option open interest and short interest prior months returns and changes in short interest are positively related but there is no rela tionship between changes in short interest and returns in the subsequent month

casting the naturalization of asylum seekers as an economic problem the asylum seekers who choose the level of investment in the host country specific human capital and the government of the host country that chooses the probability of naturalization are modeled as optimizing economic agents in a setting not of their choosing

seeking asylum in europe seeking asylum in europe over the last three decades the annual number of applications for asylum in the countries of the european union has increased from about 15 000 to more than 300 000 this has sparked a political backlash a revolution in policy a lively academic debate but very little economic analysis although the causes of asylum flows and the effects of policy are much discussed they have rarely been the subject of quantitative analysis this article examines the evolution of asylum flows and asylum policy across the eu since the early 1980s it investigates the effects of war and conflict economic incentives and asylum policies on the total numbers and on the proportions going to the different countries of the eu special attention is given to the growth of policy restrictiveness across the eu and to the harmonization of asylum policies contrary to some views policy has worked to stem the flows but it has been overwhelmed by other forces timothy j hatton

decentralized multi period economic dispatch for real time flexible demand management emerging smart grid enabling technologies will allow an unprecedented degree of observability and control at all levels in a power system combined with flexible demand and storage they could allow procuring energy at minimum cost and environmental impact that however presupposes real time coordination of demand of individual households and industries down at the distribution level with generation at the transmission level this is closely related with the balancing market economic dispatch ed problem which currently does not take into account distribution network constraints and flexible demand characteristics still assuming a suitably modified form of that problem was available due to both computational and communications requirements its centralized solution in its full detail would not be tractable while there is currently a wealth of literature dealing with distributed optimization applications in power systems it typically focuses on smaller parts of the overall energy management problem e g transmission area synchronization or electric vehicles management often without considering its full scale or establishing any association with energy market mechanisms the target of this paper is twofold 1 identify a flexible demand and distribution network inclusive formulation for ed and 2 propose a solution method

large scale integration of deferrable demand and renewable energy sources we present a stochastic unit commitment model for assessing the impacts of the large scale integration of renewable energy sources and deferrable demand in power systems in terms of reserve requirements we analyze three demand response paradigms for assessing the benefits of demand flexibility the centralized co optimization of generation and demand by the system operator demand bids and the coupling of renewable resources with deferrable loads we motivate coupling as an alternative for overcoming the drawbacks of the two alternative demand response options and we present a dynamic programming algorithm for coordinating deferrable demand with renewable supply we present simulation results for a model of the western electricity coordinating council

future lending income and security value i test the duffie g rleanu and pedersen hypothesis that security prices incorporate expected future securities lending income to determine whether institutional investors anticipate gains from future lending of securities i examine their trading behavior around loan fee increases the evidence suggests that institutions buy shares in response to an increase in lending fees and that this could explain the premium associated with high lending fee stocks expected future lending income affects stock prices although the effect seems to be attenuated by the negative information that arises from short selling