corporate social responsibility for supply chain management a literature review and bibliometric analysis corporate social responsibility csr in supply chain management scm has gained an increasing research attention in recent years extant studies have discussed stakeholder interests performance evaluation ethical sourcing and sustainable production the purpose of this paper is to develop a systematic study quantitatively depicting the knowledge structure and the intellectual progress of csr for scm this research adopts bibliometric analysis in conjunction with network analysis to systematically evaluate the csr related publications for scm the analysis involves 628 peer reviewed articles identified with careful selection of influential work data analytic techniques including citation analysis co citation analysis and co word analysis are used key findings for researchers include 1 an analytical discussion of the five sub fields that constitute the intellectual structure of csr for scm 2 theoretical and conceptual research significantly dominate in this field 3 the topics of sustainable development and economic and social effects are more frequently discussed among scholars 4 key research gaps include lacking of practical and normative modeling research and considering from the supplier perspectives in emerging economies the findings suggest that future research would emerge a greater depth of practical and modeling analysis to enrich the theories

alternative models of restructured electricity systems part 1 no market power different equilibrium concepts have been proposed by various authors schweppe et al hogan et al chao and peck wu et al to analyse competitive electricity systems we establish correspondences between these different models through a single framework and provide additional interpretations of these equilibrium concepts this unifying conceptual view also provides a computationally feasible approach to simulate the market it also opens the way to the modeling of some imperfect markets

market clearing with stochastic security part i formulation the first of this two paper series formulates a stochastic security constrained multi period electricity market clearing problem with unit commitment the stochastic security criterion accounts for a pre selected set of random generator and line outages with known historical failure rates and involuntary load shedding as optimization variables unlike the classical deterministic reserve constrained unit commitment here the reserve services are determined by economically penalizing the operation of the market by the expected load not served the proposed formulation is a stochastic programming problem that optimizes concurrently with the pre contingency social welfare the expected operating costs associated with the deployment of the reserves following the contingencies this stochastic programming formulation is solved in the second companion paper using mixed integer linear programming methods two cases are presented a small transmission constrained three bus network scheduled over a horizon of four hours and the ieee reliability test system scheduled over 24 h the impact on the resulting generation and reserve schedules of transmission constraints and generation ramp limits of demand side reserve of the value of load not served and of the constitution of the pre selected set of contingencies are assessed

thermal plant bids and market clearing in an electricity pool minimization of costs vs minimization of consumer payments the spanish wholesale electricity market started on january 1st 1998 though it is based on simple price quantity bids it incorporates some provisions to take thermal plant running requirements into account this paper presents these rules and its mathematical treatment focusing on a possible implementation of the minimum income condition which allows thermal generators to declare minimum stable loads it also shows another key point in the debate whether the algorithm should minimize costs or consumer payments

pricing of fluctuations in electricity markets abstract in an electric power system demand fluctuations may result in significant ancillary cost to suppliers furthermore in the near future deep penetration of volatile renewable electricity generation is expected to exacerbate the variability of demand on conventional thermal generating units we address this issue by explicitly modeling the ancillary cost associated with demand variability we argue that a time varying price equal to the suppliers instantaneous marginal cost may not achieve social optimality and that consumer demand fluctuations should be properly priced we propose a dynamic pricing mechanism that explicitly encourages consumers to adapt their consumption so as to offset the variability of demand on conventional units through a dynamic game theoretic formulation we show that under suitable convexity assumptions the proposed pricing mechanism achieves social optimality asymptotically as the number of consumers increases to infinity numerical results demonstrate that compared with marginal cost pricing the proposed mechanism creates a stronger incentive for consumers to shift their peak load and therefore has the potential to reduce the need for long term investment in peaking plants

foreign owned insurer performance in the us property liability markets foreign owned property liability insurers have increased their market share in the us in the recent decades they may have achieved this by being more efficient by undercutting prices to attract away business from their domestic rivals or both we investigate return risk efficiency and determinants of efficiency performance of these insurers relative to their domestic competitors we find that these firms are less profitable and less efficient in terms of cost scale and revenue x efficiencies but more efficient in terms of cost x and revenue scale efficiencies overall the evidence shows that both of the aforementioned factors have contributed to their growth

on the solution of revenue and network constrained day ahead market clearing under marginal pricing part ii case studies this paper presents the numerical analysis of the bilevel programming approach for revenue and network constrained market clearing developed in its companion paper the impact of minimum revenue conditions and minimum declared profits on generation and consumption levels as well as on locational marginal prices for energy is examined in detail through three case studies first the results from an illustrative example including minimum revenue conditions are comprehensively analyzed the second case study is based on the ieee reliability test system and considers minimum declared profits in the third case study a modified version of the ieee 118 bus system is tested while accounting for minimum revenue conditions in addition the computational behavior of the proposed approach is illustrated with several case studies including the ieee 300 bus system numerical results show the effectiveness of the proposed approach to handle revenue constraints as well as its superiority over the heuristic currently implemented in the iberian electricity market moreover simulations reveal that unlike previous works in the literature generation revenue constraints can be precisely incorporated in day ahead market clearing while explicitly considering the standard economic dispatch based marginal pricing scheme and without requiring price uplifts

trading mechanisms and stock returns an empirical investigation this paper examines the effects of the mechanism by which securities are traded on their price behavior we compare the behavior of open to open and close to close returns on nyse stocks given the differences in execution methods applied in the opening and closing transactions opening returns are found to exhibit greater dispersion greater deviations from normality and a more negative and significant autocorrelation pattern than closing returns we study the effects of the bid ask spread and the price adjustment process on the estimated return variances and covariances and discuss the associated biases we conclude that the trading mechanism has a significant effect on stock price behavior

strategic bidding of a hydropower producer under uncertainty modified benders approach this paper proposes a stochastic bilevel program for strategic bidding of a hydropower producer the price quantity and ramp rate bids are considered the uncertainty of wind power generation variation of inflows for the hydropower producer and demand variability are modeled through the moment matching scenario generation technique using discretization the stochastic bilevel program is reformulated as a stochastic mixed integer linear program milp with disjunctive constraints we propose a modified benders decomposition algorithm mbda which fully exploits the disjunctive structure of reformatted milp model more importantly the mbda does not require optimal tuning of disjunctive parameters and it can be efficiently parallelized through an illustrative 5 node example we identify possible strategies specific to a hydropower producer for maximizing profit which in turn leads to market insights we also use the ieee 24 node 118 node and 300 node case studies to show how our parallelized mbda outperforms the standard benders decomposition algorithm the parallelized mbda is also compared to the state of the art cplex solver

economic transmission augmentation with explicit modeling of the competition benefit this paper derives and evaluates a mathematical structure for identifying economically efficient transmission augmentations the mathematical structure is based on the concepts of sequential move and simultaneous move games in applied mathematics the nash equilibrium solution concept has been reformulated as an optimization problem in the proposed structure the problem of multiple nash equilibria is managed by introducing the concept of the worst case nash equilibrium both the economic concepts of the efficiency benefit and competition benefit of the transmission capacity are explicitly modeled in the proposed structure a simple three bus example system and garver s example system are employed and modified to suit the purpose of analysis a thorough economic study of these example systems is presented to highlight the concept and operation of the proposed mathematical structure from different perspectives the results demonstrate the utility of the proposed structure for measuring the total economic efficiency benefit of additional transmission capacity

margin regulation and stock market volatility using daily and monthly stock returns we find no convincing evidence that federal reserve margin requirements have served to dampen stock market volatility the contrary conclusion expressed in recent papers by hardouvelis 1988a b is traced to flaws in his test design we do detect the expected negative relation between margin requirements and the amount of margin credit outstanding we also confirm the recent finding by schwert 1988 that changes in margin requirements by the fed have tended to follow rather than lead changes in market volatility after 55 years stock market margin requirements are again a source of controversy the securities and exchange act of 1934 transferred to the federal reserve system the authority exercised previously by the new york stock exchange and other private sector exchanges to set the minimum margins i e down payments that securities brokers and dealers subsequently expanded to all lenders must require of customers purchasing common stocks on credit the transfer of authority reflected the view widely held at the time that the low initial margins set by the exchanges had fueled the stock market boom of the 1920 s and that the frenzied liquidation of shares in response to margin calls had accelerated the crash in october 1929 supposedly dragging the economy down with it congress hoped that timely raising of margin requirements by the monetary authorities might dampen speculative excesses before they raged out of control or in today s terms that margin controls might reduce market volatility what the federal reserve has done since then with its margin setting authority can be seen from figure 1 which shows the time paths both of margins and one measure of market volatility from october 1934 to december 1987 margin requirements were set initially at 45 percent raised to 55 percent during the boomlet of 1936 and then cut back to a low of 40 percent after the sharp stockmarket break in the autumn of 1937 the requirement stayed at that level for the remainder of the 30 s and most of the war years but was stepped up sharply as the war drew to a close reaching 100 percent i e all cash no borrowing for most of 1946 changes were frequent over the next two and a half decades

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

revenue adequate bidding strategies in competitive electricity markets energy trading in a competitive electricity market can be modeled as a two level optimization at the top level a centralized economic dispatch ced uses a priority list method to solve the fundamental problem of reliable market clearing with price discovery the lower level consists of a set of decentralized bidding db subproblems the db model uses a self unit scheduling simulator based on parametric dynamic programming to produce hourly bid curves for the central dispatch coordinator unit operating constraints and costs such as the unit minimum up and minimum down times ramp rates and the unit start up no load and sunk capital costs are internalized in the bid curves through the simulator a special algorithm is presented to solve the revenue adequacy problem for marginal units both ced and db models are based on the revenue maximization in contrast with the cost minimization criteria used in the conventional unit commitment uc the proposed method has been tested in a study case and some interesting results have been demonstrated

rational asset price movements without news this paper argues that an important part of movements in asset prices may be caused by neither external news nor irrationality but by the revelation of information by the trading process itself two models are developed that illustrate this general idea one model is based on investor uncertainty about the quality of other investors information the other is based on dispersion of information and small costs to trading the analysis is used to suggest a possible rational explanation of the october 1987 crash copyright 1993 by american economic association

computation of extremal nash equilibria in a wholesale power market using a single stage milp this letter proposes a new approach to the computation of extremal nash equilibria in a wholesale power market with transmission constraints the approach uses linearization techniques to formulate the extremal nash equilibrium problem as a single stage mixed integer linear programming problem which can be solved with standard software through the introduced concept of extremal nash equilibria the derived structure can efficiently locate all nash equilibria of the game we show that this approach offers significant performance improvements over existing approaches to computing nash equilibria

volume volatility and new york stock exchange trading halts trading halts increase rather than reduce both volume and volatility volume volatility in the first full trading day after a trading halt is 230 percent 50 to 115 percent higher than following pseudohalts nonhalt control periods matched on time of day duration and absolute net of market returns these results are robust over different halt types and news categories higher posthalt volume is observed into the third day while higher posthalt volatility decays within hours the extent of media coverage is a partial determinant of volume and volatility following both halts and pseudohalts but a separate halt effect remains after controlling for the media effect in the wake of the 1987 market break a number of commentators including the presidential task force on market mechanisms recommended the establishment of circuit breaker mechanisms the primary argument supporting circuit breakers both price limits and trading halts is that nontrading periods provide an opportunity for normal information transmission in times of market duress proponents of circuit breakers claim that during major price changes there can be a breakdown in the transmission of information between the trading floor and market participants therefore the primary function of a circuit breaker should be to reinform participants greenwald and stein 1988 p 17 by lowering informational asymmetries between traders halts could permit the orderly emergence of a new consensus price but would informative trading halts succeed many academics are openly suspicious of any kind of market interference and assume that trading halts are guilty until proven innocent grossman 1990 p 3 for example argues that the closing of markets merely prevents consenting adults from carrying out their desires on the floor of the stock exchange not only do halts impose a liquidity cost on traders but studies suggest that information will not be as

evaluating solvency versus efficiency performance and different forms of organization and marketing in us property liability insurance companies abstract solvency is a primary concern for regulators of insurance companies claims paying ability is a primary concern for policyholders and return on investment is a primary concern for investors these interests potentially conflict and the decision makers for the firm must trade off one concern versus another here we examine the efficiency of insurance companies via data envelopment analysis using solvency claims paying ability and return on investment as outputs and using a financial intermediary model for the insurance company the effect of solvency on efficiency is then examined these efficiency evaluations are further examined to study stock versus mutual form of organizational structure and agency versus direct marketing arrangements which are examined separately and in combination

the switch from continuous to call auction trading in response to a large intraday price movement some european exchanges e g euronext frankfurt and madrid make use of a mechanism to moderate price volatility that was proposed by madhavan 1992 as preferable to a trading halt in times of market stress it consists of a temporary switch from continuous to call auction trading in an individual security whenever its price moves beyond predetermined limits this article studies whether this mechanism sharpens the information content of prices dampens volatility and normalizes trading volume and intensity taking intraday data for the madrid order driven continuous market i find post switch improvements in the information content of prices and reductions in volatility especially for thinly traded stocks trading volume and intensity peaked around auctions but soon returned to preevent levels

social optimality and cooperation in nonatomic congestion games abstract congestion externalities may result in nonoptimal equilibria for these to occur it suffices that facilities differ in their fixed utilities or costs as this paper shows the only case in which equilibria are always socially optimal regardless of the fixed components in that in which the costs increase logarithmically with the size of the set of users therefore achieving a socially optimal choice of facilities generally requires some form of external intervention or cooperation for heterogeneous populations in which the fixed utilities or costs vary across users as well as across facilities this raises the question of utility or cost sharing the sharing rule proposed in this paper is the harsanyi transferable utility value of the game which is based on the users marginal contributions to the bargaining power of coalitions

sequential coordination of transmission expansion planning with strategic generation investments this paper proposes mathematical models for sequential coordination of transmission expansion planning with strategic generation investments the proactive and reactive coordinations are modeled and studied the interaction between transmission company transco and strategic generation companies gencos is modeled using the sequential move game this is while the interaction between the strategic gencos is modeled as a simultaneous move game in the proactive coordination the transco expands its future transmission capacities taking into account the strategic investments by gencos in the reactive coordination strategic gencos move first and expand their future generation capacities and then transco expands the transmission capacity the proactive coordination is modeled as a mixed integer bilevel linear program miblp and the reactive coordination is modeled as a mixed integer linear program milp the miblp has binary variables in both upper and lower levels the moore bard algorithm is parallelized and used to solve the miblp the mathematical models and the parallelized moore bard algorithm are tested on 3 bus and 6 bus example systems and the modified ieee rts96 also the ieee 118 bus test system is studied using a heuristic version of the moore bard algorithm

public information arrival we develop a measure of public information flow to financial markets and use it to document the patterns of information arrival with an emphasis on the intraday flows the measure is the number of news releases by reuter s news service per unit of time we find that public information arrival is nonconstant displaying seasonalities and distinct intraday patterns next we relate our measure of public information to aggregate measures of intraday market activity our results suggest a positive moderate relationship between public information and trading volume but an insignificant relationship with price volatility

nash equilibrium in strategic bidding a binary expansion approach this paper presents a mixed integer linear programming solution approach for the equilibrium problem with equilibrium constraints epec problem of finding the nash equilibrium ne in strategic bidding in short term electricity markets a binary expansion be scheme is used to transform the nonlinear nonconvex ne problem into a mixed integer linear problem milp which can be solved by commercially available computational systems the be scheme can be applicable to cournot bertrand or joint price quantity bidding models the approach is illustrated in case studies with configurations derived from the 95 gw brazilian system including unit commitment decisions to the price maker agents

order flow and liquidity around nyse trading halts we study order f low and liquidity around nyse trading halts we find that market and limit order submissions and cancellations increase significantly during trading halts that a large proportion of the limit order book at the reopen is composed of orders submitted during the halt and that the market clearing price at the reopen is a good predictor of future prices depth near the quotes is unusually low around trading halts though specialists and0or f loor traders appear to provide additional liquidity at these times finally specialists appear to spread the quote prior to imbalance halts to convey information to market participants the costs and benef its associated with new york stock exchange trading halts are the subject of continuous debate the stated purpose of trading halts is to allow investors a chance to react to new information and to facilitate the orderly emergence of a new equilibrium price see e g nyse 1999 however little is known about the extent or nature of investor reactions to trading halts furthermore it is unclear whether these reactions support or confound attempts to reach a new equilibrium price to address these issues we use nonpublic nyse data on all superdot electronic orders to analyze the effects of trading halts on order f low spreads and the limit order book we also examine the relationships between the limit order book and the reopening price and between liquidity and post halt volatility information on order f low is an important missing element in the ongoing debate about the usefulness of trading halts one argument against trading halts is that they impede price formation because trading aggregates information that is distributed across market participants however submissions and cancellations of orders during a halt may provide an alternative source of information that combined with published indications of possible reopening prices may assist with price formation an argument in favor of trading halts is that when traders are given an opportunity to cancel orders

implementation in economies with a continuum of agents we study a general implementation problem for exchange economies with a continuum of players and private information and test the robustness of the results for sequences of approximating finite economies assuming that the designer knows the distribution of the characteristics in the economy we consider continuous and unique implementation in both its equilibrium and dominant strategies versions and obtain results for general self selective first and second best allocations an upper hemicontinuity property of bayesian equilibria of approximating economies for continuous mechanisms is demonstrated using this we can for example conclude that if a given continuous mechanism implements uniquely a walrasian allocation in the continuum economy then all bayesian equilibria of large approximation economies will with probability close to one yield an allocation which is almost ex post pareto optimal

the robustness of output measures in property liability insurance efficiency studies abstract we empirically examine two methods for measuring output in property liability insurer efficiency studies the value added approach and the flow or financial intermediation approach the approaches are not mutually consistent the value added approach is closely related to traditional measures of firm performance but the flow approach is not in addition efficient value added approach firms are less likely to go insolvent while firms characterized as efficient by the flow approach are generally more likely to fail we also find that the theoretical concern regarding the value added approach s use of losses as a measure of output is not validated empirically

efficiency in the international insurance industry a cross country comparison the purpose of this paper is to provide new empirical evidence on frontier efficiency measurement in the international insurance industry a topic of great interest in the academic literature during the last several years a broad efficiency comparison of 6462 insurers from 36 countries is conducted different methodologies countries organizational forms and company sizes are compared considering life and non life insurers we find a steady technical and cost efficiency growth in international insurance markets from 2002 to 2006 with large differences across countries denmark and japan have the highest average efficiency whereas the philippines is the least efficient regarding organizational form the results are not consistent with the expense preference hypothesis which claims that mutuals should be less efficient than stocks due to higher agency costs only minor variations are found when comparing different frontier efficiency methodologies data envelopment analysis stochastic frontier analysis

program trading and intraday volatility program trading and intraday changes in the s p 500 index are correlated future prices and to a lesser extent cash prices lead program trades index arbitrage trades are followed by an immediate change in the cash index which ultimately reverses slightly no reversal follows nonarbitrage trades the cumulative index changes associated with buy and sell trades and with arbitrage and nonarbitrage trades all are similar price decompositions suggest that the results are not due to microstructure effects program trades in this 1989 1990 sample do not seem to have created major short term liquidity problems the results are stable within the sample many practitioners regulators and public commentators have expressed concerns about potential destabilizing effects of program trading they argue that program trades especially index arbitrage programs increase intraday volatility and decrease

capacity expansion equilibria in liberalized electricity markets an epec approach this paper presents a novel way to model the generation capacity expansion problem in a liberalized framework via a multi year bilevel equilibrium model in the upper level the competing generation companies maximize their individual profits while the lower level represents the market using a conjectured price response approach which allows us to vary the strategic spot market behavior to see how much the reigning competitive behavior impacts investment decisions the bilevel equilibrium model is formulated as an equilibrium problem with equilibrium constraints transformed into a mixed integer linear program and solved as such using diagonalization in order to verify equilibria we present a case study to apply this new modeling approach and to demonstrate that the proposed equilibrium problem with equilibrium constraints can have multiple solutions whose respective investments can vary

foreword for the special section on wind and solar energy uncovering and accommodating their impacts on electricity markets the articles in this special section focus on wind and solar energy and the impact these energy technologies and services will have the utility markets the aim is to give particular focus on some of the areas of investigation that may allow to 1 uncover the impact of renewables on electricity market e g on market clearing outcomes need for ancillary services and investment and to 2 propose methodological innovations being theoretically sound and of practical relevance in order to accommodate substantial shares of renewables in power systems electricity network and markets were designed based on a long history of dealing with various forms of dispatchable generation as well as a fairly predictable inelastic electricity consumption pattern in a centralized top down manner little uncertainty was involved on both generation and demand sides hence allowing for a design of electricity markets accounting for the necessity of a forward optimal allocation with a real time mechanism supporting actual power system operation

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

coordination in markets with nonconvexities as a mathematical program with equilibrium constraints part i a solution procedure this paper is concerned with developing an algorithm for solving the coordination problem that arises in a new equilibrium model which for the purpose of this presentation applies to a static no time coupling costs or constraints electricity pool market with price inelastic demand and no network the new equilibrium model has the following main properties i every scheduled generator satisfies its minimum surplus or bid profit condition ii the energy price is a system marginal cost lagrange multiplier associated with the power balance constraint in the related economic dispatch problem where all of the discrete variables are fixed to their optimal values iii the power balance and all the generators technical constraints are satisfied to solve the coordination problem which is a subproblem of the new equilibrium model it is mathematically convenient to cast the former as a three level nested optimization problem we substitute the ensuing lower level subproblems with an equivalent set of explicit algebraic equalities and inequalities hence we obtain a one level problem which is a discrete continuous mathematical program with complementarity or equilibrium constraints mpec finally we transform the one level mathematical program into mixed integer linear form by substitution of the complementarity terms and the remaining nonlinear terms

generation flexibility in ramp rates strategic behavior and lessons for electricity market design abstract a ramp rate usually defines the speed at which an electric power producer can decrease or increase its production in limited time the availability of fast ramping generators significantly affects the economic dispatch especially in the systems with high penetration of intermittent energy sources e g wind power since the fluctuations in supply are common and sometimes unpredictable one of the regulatory practices of how to impel generators to provide their true ramp rates is to separate the stages of submitting the bids on ramp rate and production in this paper we distinguish two types of market structures one stage when electric power producers are deciding their production and ramp rate at the same time or two stage when generators decide their ramp rate first and choose their production levels at the second stage we employ one stage and two stage equilibrium models respectively to represent these market setups and use a conjectured price response parameter ranging from perfect competition to the cournot oligopoly to investigate the effect of the market competition structure on the strategic decisions of the generators we compare these two market setups in a symmetric duopoly case with two time periods and prove that in the two stage market setup the level of ramp rate is independent of the strategic behavior in the spot market and generally lower than the one offered in the one stage setup we also show that the ramp rate levels in one and two stage models coincide at the cournot oligopoly we extend the model to asymmetry several load periods portfolio bidding and uncertainty and show that withholding the ramp rate still occurs in both models our findings prove that market regulators cannot rely on only separating the decision stages as an effective measure to mitigate market power and in certain cases it may lead to an adverse effect

pricing energy and ancillary services in integrated market systems by an optimal power flow a detailed ac opf based formulation for procuring pricing and settling energy and ancillary service in simultaneous auctions by integrated market systems is presented the paper provides clear definitions of locational marginal prices for energy and ancillary service marginal prices in terms of lagrange multipliers the characteristics of the prices are analyzed especially when economic substitution among ancillary services is required the paper also evaluates the conditions under which opportunity costs are incurred to units that provide ancillary services it is particularly shown that the intuitive belief that the provision of regulation down service does not incur opportunity cost to the provider in general is not true

stock market structure and volatility the procedure for opening stocks on the nyse appears to affect price volatility an analytical framework for assessing the magnitude of the structurally induced volatility is presented the ratio of variance of open to open returns to closeto close returns is shown to be consistently greater than one for nyse common stocks during the period 1982 through 1986 tbe greater volatility at the open is not attributable to the way in which public information is released since both the opento open return and the close to close return span the same period of time instead the greater volatility appears to be attributable to private information revealed in trading and to temporaryprice deviations induced by specialist and other traders the implied cost of immediacy at the open is significantly higher than at the close other empirical evidence in this article documents the volume of trading at the open the time delays between the exchange opening and the first transaction in a stock the difference in daytime volatility versus overnight volatility and the extent to which volatility is related to trading volume

bounding the inefficiency of equilibria in nonatomic congestion games abstract equilibria in noncooperative games are typically inefficient as illustrated by the prisoner s dilemma in this paper we quantify this inefficiency by comparing the payoffs of equilibria to the payoffs of a best possible outcome we study a nonatomic version of the congestion games defined by rosenthal int j game theory 2 1973 65 and identify games in which equilibria are approximately optimal in the sense that no other outcome achieves a significantly larger total payoff to the players games in which optimization by individuals approximately optimizes the social good in spite of the lack of coordination between players our results extend previous work on traffic routing games

on the solution of revenue and network constrained day ahead market clearing under marginal pricing part i an exact bilevel programming approach the first of this two paper series addresses a practical day ahead auction model where generation revenue constraints are explicitly incorporated in the problem formulation as routinely done in several national electricity markets across europe the revenue constrained market clearing procedure includes the effect of the transmission network inter temporal constraints associated with generation scheduling demand side bidding and marginal pricing this auction design is an instance of price based market clearing which features two major complicating factors first locational marginal prices become decision variables of the optimization process in addition producer revenues are formulated as bilinear and highly nonconvex products of power outputs and market clearing prices the resulting problem is formulated as a mixed integer nonlinear bilevel program with bilinear terms for which available solution techniques rely on heuristics approximations or modeling simplifications this paper presents a novel and exact methodology whereby the original problem is recast as an equivalent single level mixed integer linear program as a consequence finite convergence to optimality is guaranteed and the use of standard commercial software is allowed the proposed transformation is based on duality theory of linear programming karush kuhn tucker optimality conditions and integer algebra results in the second part of this two paper series numerical results from several case studies illustrate the effective performance of the proposed solution approach

security constrained unit commitment with ac constraints in a restructured power market the independent system operator iso executes the security constrained unit commitment scuc program to plan a secure and economical hourly generation schedule for the day ahead market this paper introduces an efficient scuc approach with ac constraints that obtains the minimum system operating cost while maintaining the security of power systems the proposed approach applies the benders decomposition for separating the unit commitment uc in the master problem from the network security check in subproblems the master problem applies the augmented lagrangian relaxation lr method and dynamic programming dp to solve uc the subproblem checks ac network security constraints for the uc solution to determine whether a converged and secure ac power flow can be obtained if any network violations arise corresponding benders cuts will be formed and added to the master problem for solving the next iteration of uc the iterative process will continue until ac violations are eliminated and a converged optimal solution is found in this paper a six bus system and the ieee 118 bus system with 54 units are analyzed to exhibit the effectiveness of the proposed approach

trading structure and overnight information a natural experiment from the tel aviv stock exchange abstract a unique data set from the tel aviv stock exchange tase is used to study the effect of trading mechanisms on stock return volatility the tase represents a natural experiment which allows separation of the overnight information effect from the trading mechanism effect the data span a time period in which the order of the trading mechanisms a sequential continuous mechanism and a call auction was switched since overnight information should impact opening prices equally across periods this affords an unparalleled opportunity to examine the trading mechanism effect without the confounding effect of the non trading period this paper finds that the null that opening variances equal closing variances cannot be rejected for either period further the tests cannot reject null that the ratio of opening to closing return variances is equal across periods this suggests that the trading mechanisms on the tase do not differ in their effect upon return volatility

electricity market near equilibrium under locational marginal pricing and minimum profit conditions this paper provides a tool to determine the near equilibrium of an electric energy market this market works under locational marginal pricing i e generating units and demand loads are paid and pay respectively the locational marginal prices corresponding to the nodes they are connected to the near equilibrium is defined as the energy transaction levels for which generating companies maximize their respective profits and consumption companies maximize their respective utilities an independent system operator clears the market maximizing the social welfare conditions that ensure minimum profit for generating units can be included however these conditions may render a generating unit uncompetitive and expel it from the market demands are taken to be non constant and values are determined as part of the solution the near equilibrium is obtained through the solution of a mixed integer quadratic problem equivalent to a mixed linear complementarity problem that includes the minimum profit conditions it is important to note that the near equilibrium concept presented in this paper does not solve a market equilibrium when indivisibilities such as start up costs or the like are present lastly we validate the proposed model on a case study using data from the ieee reliability test system

opening prices on the new york stock exchange abstract the prices of opening transactions on the new york stock exchange are determined quite differently from prices of subsequent transactions this paper tests the null hypothesis that opening prices are as representative of contemporaneous equilibrium stock values as subsequent intra day transactions prices with one possible exception there is no basis for rejecting this hypothesis despite the very different trading mechanisms used in opening trades and intra day trades

how does the call market method affect price efficiency evidence from the singapore stock market abstract on august 21 2000 the singapore exchange sgx adopted the call market method to open and close the market while the remainder of the day s trading continued to rely on the continuous auction method the call method significantly improved the price discovery process and market quality a positive spillover effect is observed from the opening and closing calls day end price manipulation also declined after the introduction of the call market method however the beneficial impact from the call market method is asymmetric benefiting liquid stocks more than illiquid stocks

the dependence between hourly prices and trading volume this study provides evidence on joint characteristics of hourly common stock trading vol ume and returns on the new york stock exchange average volume traded shows signifi cant differences across trading hours of the day and across days of the week average returns differ across hours ofthe day and to some extent across days ofthe week there is a strong contemporaneous relation between trading volume and returns and also a rela tion between trading volume and returns lagged up to four hours furthermore the trading volume returns relation is steeper for positive returns than for nonpositive returns

enhanced models and improved solution for competitive biofuel supply chain design under land use constraints abstract this paper studies the effect of government regulation on farmland use to balance food and energy production in a competitive biofuel supply chain design framework we propose a stackelberg nash game model with a direct land use constraint that captures farmland food and fuel market equilibrium to provide farmers with incentives to comply with the land use regulation we implement the land use constraint through a cap and trade mechanism which we show attains equivalent land use patterns we further prove the existence of optimal solutions of the two equivalent discretely constrained mathematical program with equilibrium constraints dc mpec models two adaptive relax and tighten schemes integrality and lagrangian duality based relaxation are proposed to handle the binary variables in a mixed integer formulation of the models the proposed methodology is tested in a case study for the state of illinois the computational results demonstrate the superiority of our customized algorithms to publicly available solvers for solving problems with realistic sizes finally the efficiency of the cap and trade mechanism is demonstrated through comparisons of scenarios with and without regulation as well as a sensitivity analysis on the cap and trade level the cap and trade policy is found to effectively reduce biomass farmland use and profits of the biofuel industry it may have different impacts on social welfare depending on problem settings and market parameters cap and trade levels also affect system behavior and thus should be carefully selected

organization and efficiency in the international insurance industry a cross frontier analysis abstract this paper employs cross frontier analysis an innovative tool based on data envelopment analysis to provide new insight into the relationship between organization and efficiency in international insurance markets we are the first to empirically test the expense preference hypothesis and the efficient structure hypothesis in a large cross country study for this purpose we consider 23 807 firm years for 21 countries from northern america and the european union a dataset not previously analyzed in this context we find evidence for the efficient structure hypothesis in selected market segments but we find no evidence for the expense preference hypothesis our results provide insight into the competitiveness of stock and mutual insurers from different countries at the country level the results can be used to compare different insurance markets our findings are especially interesting for the strategic management of insurance companies as well as for regulators and boards of national insurance associations

introduction to nber symposium on the october 1987 crash the stock market crash of october 1987 led to a boom in conferences commissions and studies of the stock market in almost each case the participants would try to understand the events of october 1987 by a detailed analysis or description of events during the particular days of high volatility of course to us economists there was nothing qualitatively unusual about october 19 1987 the stock market moved and we have no model that succeeds in explaining the magnitude or sources of daily stock market volatility for that day or any other day when asked by the national bureau of economic research to organize yet another conference on this subject i decided that it was time to put these events in a historical perspective and try to understand them in the context of longer time periods and broader models the papers collected in this symposium issue admirably succeed in broadening our understanding of market volatility and consequently deepening our understanding of the events of a few important days to develop some perspective for the papers in the symposium and impose my own prejudices on the reader it is useful to partition the sources of stock price movement 1 first the price of equity can change for purely informational reasons related to the market receiving news that changes its perception of the payoff stream to holding equity e g the expected dividends or volatility of the dividend may change sec

auction design in day ahead electricity markets competition in day ahead electricity markets has been established through auctions where generators and loads bid prices and quantities different approaches have been discussed regarding the market auction design multi round auctions despite its implementation complexity allow market participants to adapt their successive bids to market prices considering their operational and economic constraints however most of the day ahead electricity market implementations use noniterative single round auctions this paper presents a market simulator to compare both auction models different auction alternatives such as the spanish single round auction that takes into account special conditions included in the generator bids and multi round auctions with different stopping rules are analyzed the results and acquired experience in the simulation of the spanish market started in january 1998 are presented hourly market prices average daily price price demand correlation and several economic efficiency indicators such as generator surplus consumer surplus and social welfare are compared to derive conclusions regarding the performance of the auction alternatives

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

exercise of market power on ramp rate in wind integrated power systems with an increasing penetration of wind power there is likely to be an increasing need for fast ramping generating units these generators ensure that no load is lost if supply drops due to the uncertainties in wind power generation however it is observed in practice that in a presence of network constraints fast ramping generating units are prone to act strategically and exercise market power by withholding their ramp rates in this paper we model this gaming behavior on ramp rates we assume a market operator who collects bids in form of marginal costs quantities and ramp rates he runs a ramp constrained economic dispatch given the generators bids forecasted demand and contingencies following the game theoretic concepts we set up a multi level optimization problem the lower level problem is the ramp constrained economic dispatch and the higher level represents the profit maximization problems solved by strategic generators the whole problem is formulated as an equilibrium problem with equilibrium constraints epec the outcome of the epec problem is a set of nash equilibria to tackle the multiple nash equilibria problem the concept of the extremal nash equilibria is defined and formulated we model the concept of extremal nash equilibria as a single stage mixed integer linear programming problem milp and demonstrate the application of this mathematical framework on an illustrative case and on a more realistic case study with tractable results

contingency constrained reserve requirements in joint energy and ancillary services auction this paper presents a security constrained unit commitment model for energy and ancillary services auction which can be used by an iso to optimize reserve requirements in electricity markets the proposed day ahead algorithm determines reserve requirements by simulating contingencies rather than specifying the requirements as fixed system constraints to address the computational complexity the original auction problem is decomposed into a master problem for solving unit commitment and subproblems for considering network security constraints numerical examples show that the proposed joint auction model can clear energy and ancillary services bids simultaneously while minimizing the total operating cost and satisfying transmission security constraints

finding equilibria in the pool based electricity market with strategic wind power producers and network constraints this paper proposes a model to find the equilibria in the short term electricity market with large scale wind power penetration the behavior of each strategic player is modeled through a two stage mathematical problem with equilibrium constraints mpec where the upper level problem maximizes the profit of the strategic player and the lower level problem describes the clearing processes of the day ahead and real time markets while considering the network constraints the joint solution of all the mpecs constitutes an equilibrium problem with equilibrium constraints epec the uncertain wind power production and demand are represented by a set of plausible scenarios by using the duality theory and karush kuhn tucker condition each mpec is transferred into a mixed integer linear programing problem the nash equilibria of the electricity market are obtained by solving the epec using game theory and the diagonalization algorithm case studies are performed to show the effectiveness of the proposed model

national strategic investment in european power transmission capacity abstract the transformation of the european electricity system requires substantial investment in transmission capacity to facilitate cross border trade and to efficiently integrate renewable energy sources however network planning in the eu is still mainly a national prerogative in contrast to other studies aiming to identify the pan european continental welfare optimal transmission expansion we investigate the impact of zonal planners deciding on network investment strategically with the aim of maximizing the sum of consumer surplus generator profits and congestion rents in their jurisdiction this reflects the inadequacy of current mechanisms to compensate for welfare re allocations across national boundaries arising from network upgrades we propose a three stage equilibrium model to describe the nash game between zonal planners i e national governments regulators or system operators each taking into account the impact of network expansion on the electricity spot market and the resulting welfare effects on the constituents within its jurisdiction we propose a novel way to solve the resulting gne epec type problem using a variation of a disjunctive constraints reformulation this allows to solve this problem without a priori assumptions on the relative valuation of shared constraints by each player using a four node sample network we identify several nash equilibria of the game between the zonal planners this example illustrates the failure to reach the first best welfare expansion in the absence of an effective framework for cross border cost benefit allocation

an efficiency comparison of the non life insurance industry in the bric countries abstract we analyze the efficiency of non life insurance companies in four of the fastest growing markets in the world the bric brazil russia india china countries an innovative feature of this paper is its incorporation of uncontrollable variables in the efficiency analysis using multi stage data envelopment analysis dea this approach captures cross country differences such as the political and economic environment and allows distinguishing between managerial inefficiency and inefficiency due to environmental conditions we find that the environment affects the efficiency of non life insurers operating in the bric countries furthermore in a regression of firm characteristics on efficiency scores we identify four drives of efficiency size profitability solvency and ownership form the results further our understanding of the insurance industry in the bric countries in regard to its efficiency and the environment in which it operates

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

improved transmission representations in oligopolistic market models quadratic losses phase shifters and dc lines practical models of competition among power generators who possess market power have generally had to use simplified models of transmission costs and constraints in order to be tractable in particular the linearized dc load flow model has been popular in complementarity and other types of oligopoly models in this paper we show how such models can be generalized to include quadratic losses controllable dc lines and phase shifting transformers these generalizations preserve convexity of the feasible region a property that facilitates computation and proof of solution uniqueness and existence piecewise and successive linearization formulations are also provided that allow consideration of nonlinear losses in models that require linear constraints a simple six bus example illustrates the application of these generalizations in that example the impact of losses on prices is much greater under strategic behavior than under competition large scale applications of these approaches to markets in western north america and the european union illustrate how inclusion of nonlinear losses and controllable dc lines can affect estimates of prices flows and economic efficiency indices resulting from oligopoly models

auction implementation problems using lagrangian relaxation lagrangian relaxation lr is used as an auction method for bidding in a deregulated environment this paper focuses on the problems that occur while using lr as an auction method identical or similar units can prevent lr from finding the optimal solution if the units are similar lr may have trouble selecting some of them for the optimal solution a feasible solution may thus not be found since a heuristic selection of which unit data to alter has to be applied this is inequitable to the unit s not selected and may result in lawsuit s because the dispatcher has to use heuristic selection there is no fair solution to these problems the authors suggest previously published methods to implement auctions sensitivity analysis has also been applied in this paper to show that the percentage difference of similarity between units may affect the solution found

a simulation model for a competitive generation market the simulation of a wholesale electricity market should go beyond a simple optimization based on the operating costs of the generating units a model of a competitive electricity market must consider the market structure the strategy of the market participants and any other factor that lead to prices different from costs this paper presents cosmee a model of a wholesale electricity market based on simple bids that estimates expected bid prices and quantities system hourly prices and generation schedules taking into account the bidding strategies of generators and the structure of the market the model reflects the profit maximizing behavior of the market agents subject to different types of constraints cosmee has been used to simulate a real wholesale market

trading and returns under periodic market closures this paper studies how market closures affect investors trading policies and the resulting return generating process it shows that closures generate rich patterns of time variation in trading and returns including those consistent with empirical findings 1 u shaped patterns in the mean and volatility of returns over trading periods 2 higher trading activity around the close and open 3 more volatile open to open returns than close to close returns 4 higher returns over trading periods than over nontrading periods 5 more volatile returns over trading periods than over nontrading periods it also shows that closures can make prices more informative about future payoffs we model a competitive stock market with periodic closures in which investors trade for both allocational and informational reasons we use the model to study how market closures intrinsically affect investors trading behavior and the return generating process the purpose of this analysis is to increase our understanding of the time variation in security trading and returns that are associated with regular market closures such as the intraday and intraweek patterns in stock returns volatility and trading volume we consider a stock market in which the exogenous information flow is homogeneous over time and the market closes periodically when the market is open investors trade the stock either to rebalance their overall portfolio of assets which also includes other illiquid assets or to speculate on future stock payoffs using their private information in particular investors adjust their asset portfolio by trading the stock in order to hedge the risk of illiquid assets we refer to these trades as hedging trades and those motivated by private information as speculative trades when the market is closed hong is from the graduate school of business stanford university and wang is from the sloan school of management massachusetts institute of technology and nber the authors thank jennifer huang for programming assistance and an anonymous referee for many valuable suggestions they also thank glenn ellison john heaton craig holden andrew lo steve slezak jeremy stein rene stulz the editor the nber asset pricing lunch group and par

residential electricity pricing in china the context of price based demand response abstract as a secondary energy electricity is an important channel between original energy and energy consumers electricity price is a critical factor for the interests of all involvers in the electric power market it also plays an important role for the sustainable development of energy and environment smart grid is a new conception proposed in recent years to improve the intelligent level and increase the efficiency of electric power system operation smart grid combines and integrates information technology communication technology and intelligent control technology with tradition power system to achieve the many objectives of smart grid demand response dr as an effective technique of demand side management dsm refers to the changes in electricity consumption behavior of users in response to the dynamic price or incentive rewards price based demand response pbdr is one of the two major dr programs in this paper we first introduce the pricing theories in economics the pricing of electricity and the development of electricity pricing in china then we present a detailed discussion on the pbdr strategies in the dsm of smart grid also the research status of pbdr is reviewed finally it gives a summary of the whole paper in the last section

a transaction data study of weekly and intradaily patterns in stock returns abstract weekly and intradaily patterns in common stock prices are examined using transaction data for large firms negative monday close to close returns accrue between the friday close and the monday open for smaller firms they accrue primarily during the monday trading day for all firms significant weekday differences in intraday returns accrue during the first 45 minutes after the market opens on monday mornings prices drop while on the other weekday mornings they rise otherwise the pattern of intraday returns is similar on all weekdays most notable is an increase in prices on the last trade of the day

strategic bidding under uncertainty a binary expansion approach this work presents a binary expansion be solution approach to the problem of strategic bidding under uncertainty in short term electricity markets the be scheme is used to transform the products of variables in the nonlinear bidding problem into a mixed integer linear programming formulation which can be solved by commercially available computational systems the be scheme is applicable to pure price pure quantity or joint price quantity bidding models it is also possible to represent transmission networks uncertainties scenarios for price quantity plant availability and load financial instruments capacity reinforcement decisions and unit commitment the application of the methodology is illustrated in case studies with configurations derived from the 80 gw brazilian system

finding multiple nash equilibria in pool based markets a stochastic epec approach we present a compact formulation to find all pure nash equilibria in a pool based electricity market with stochastic demands the equilibrium model is formulated as a stochastic equilibrium problem subject to equilibrium constraints epec the problem is based on a stackelberg game where the generating companies gencos optimize their strategic bids anticipating the solution of the independent system operator iso market clearing a finite strategy approach both in prices and quantities is applied to transform the nonlinear and nonconvex set of nash inequalities into a mixed integer linear problem milp a procedure to find all nash equilibria is developed by generating holes that are added as linear constraints to the feasibility region the result of the problem is the set of all pure nash equilibria and the market clearing prices and assigned energies by the iso a case study illustrates the methodology and proper conclusions are reached

price formation on stock exchanges the evolution of trading within the day prior analyses of prices of the nyse and other exchanges find that transitory price volatility is greater at the open of trading than at the close we extend this line of research by using 40 years of hourly dow jones 65 composite price index data to estimate transitory volatility throughout the trading day our results indicate that transitory volatility steadily declines during the trading day we find a similar intraday decline in transitory volatility for a 2 1 2 year sample of the individual firms in the dow jones 30 industrials index the results are consistent with the hypothesis that trading aids price formation and do not support the argument that particular trading mechanisms are the source of greater volatility at the open of trading article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

an examination of stock market return volatility during overnight and intraday periods 1964 1989 this paper examines the variance of hourly market returns during 1964 89 results indicate that return volatility falls from the opening hour until early afternoon and rises thereafter and is significantly greater for intraday versus overnight periods market variance is also shown to change significantly over time rising after nasdaq began in 1971 rising after trading in stock options began in 1973 falling after fixed commissions were eliminated in 1975 rising after trading in stock index futures was introduced in 1982 and falling after margin requirements for stock index futures became larger in 1988 copyright 1990 by american finance association

linear complementarity models of nash cournot competition in bilateral and poolco power markets two cournot models of imperfect competition among electricity producers are formulated as mixed linear complementarity problems lcps and a simple example is presented to illustrate their application the two models simulate bilateral markets the models include a congestion pricing scheme for transmission but other transmission pricing approaches can also be represented in this framework the two models differ from each other in that one has no arbitrage between nodes of the network while in the other model arbitragers erase any noncost based differences in price the latter bilateral model turns out to be equivalent to a cournot model of a poolco the models differ from other cournot market models in that they include both of kirchhoff s laws via a dc approximation can include arbitragers possess unique solutions and are readily solved by efficient lcp algorithms the key assumption that permits their formulation as lcps is that each producer naively assumes that its output will not affect transmission prices

demand side reserve offers in joint energy reserve electricity markets we propose a market model that includes demand side reserve offers and where energy and reserve are jointly dispatched generators and consumers can submit offers and bids on five distinct products energy upspinning reserve downspinning reserve and two kinds of standby reserve the resources are scheduled and dispatched in a joint auction through a mixed integer optimization program the extra scheduling flexibility introduced by demand side reserve offers can lead to significant gains in economic efficiency thus the results suggest that not only do the consumers increase their profits but in addition the market power of the generators is reduced

demand shifting bids in energy auction with non convexities and transmission constraints the major objective of this paper was to propose clearing and pricing models suitable for demand shifting bids in the efficient but non convex pool based auction complex generators offers bring non convexities into the efficient auctions due to e g start up costs and times this paper focused on the responsive demands introducing simple yet adequate linear constraints into a multi period bid offer based optimal power flow opf dc model as the standard locational marginal prices lmps may not support the auction outcomes due to non convexities uplifts are needed to reduce generators loss previous work has developed a minimum uplift pricing model that directly optimizes prices so that uplifts arising from generators profit suboptimality and simple elastic demands benefit suboptimality are minimized this work extended the mixed integer linear programming milp formulation of the previous model to incorporate new linear constraints defining benefit suboptimality of demand shifting bids furthermore the transmission constrained market was attempted as a result the buyers were protected against over curtailment moreover prices complemented with minimum uplifts were fair for both generators and demands the models were validated on the literature based cases including ieee rts 24 node 24 hour system

biofuel supply chain design under competitive agricultural land use and feedstock market equilibrium abstract the rapid expansion of the biofuel industry diverts a large amount of agricultural crops as energy feedstocks and in turn affects farm land allocation feedstock market equilibrium and agricultural economic development in local areas in this paper we propose game theoretic models that incorporate farmers decisions on land use and market choice into the biofuel manufacturers supply chain design problem a noncooperative bi level stackelberg leader follower game model and a cooperative game model are developed respectively to address possible business partnership scenarios between feedstock suppliers and biofuel manufacturers the models determine the optimal number and locations of biorefineries the required prices for these refineries to compete for feedstock resources as well as farmers land use choices between food and energy using corn as an example of feedstock crops spatial market equilibrium is utilized to model the relationship between corn supply and demand and the associated price variations in local grain markets with linear corn demand functions we develop a solution approach that transforms the original discrete mathematical program with equilibrium constraints dc mpec into to a solvable mixed integer quadratic programming miqp problem based on karush kuhn tucker kkt conditions the proposed methodology is illustrated using an empirical case study of the illinois state the computation results reveal interesting insights into optimal land use strategies and supply chain design for the emerging biofuel economy

direct minimum uplift model for pricing pool based auction with network constraints auctions with non convexities as considered in this paper use a multi period optimal power flow opf model based on generators offers to calculate efficient schedules the standard locational marginal prices lmps may not support these schedules and uplifts are needed to help the generators break even this paper presents a direct minimum uplift dmu pricing model which is formulated as a mixed integer linear programming problem with uplift minimization objective new dmu prices are major variables constrained with decomposition formula based on shift factors similar to the actual practice of developing lmps the remaining constraints reflect the generators profits and uplifts modeled as functions of the dmu prices the main feature of the dmu model is individual rationality attained in pool based auction under prices properly reflecting network constraints complemented with minimum uplifts the model is validated on several cases including the ieee 24 node system

modelling round the clock price discovery for cross listed stocks using state space methods u s trading in non u s stocks has grown dramatically around the clock these stocks trade in the home market in the u s market and potentially in both markets simultaneously we develop a general methodology based on a state space model to study 24 hour price discovery in a multiple markets setting as opposed to the standard variance ratio approach this model deals naturally with 1 simultaneous quotes in an overlap 2 missing observations in a nonoverlap 3 noise due to transitory microstructure effects and 4 contemporaneous correlation in returns due to market wide factors we apply our model to dutch stocks cross listed in the united states our findings suggest a minor role for the new york stock exchange in price discovery for dutch shares in spite of its nontrivial and growing market share

stock market microstructure and return volatility evidence from italy abstract this paper studies the impact of the stock market microstructure on return volatility and on the value discovery process in the milan stock exchange the primary trading mechanism employed by this exchange is a call market which is usually preceded and followed by trading in a continuous market we find that the opening transaction in the continuous market has the highest volatility and that opening the market with the call transaction seems to produce relatively lower volatility in the closing transaction investors correct perceived errors or noise in the prices set at the call the implications of the results for market design are examined

coordination of generation and transmission development through generation transmission charges a game theoretical approach transmission charges aim to recover the cost of transmission network investments and provide efficient locational signals to new generators in this paper we investigate the effect of these charges on the development of new generation capacities in the system generation expansion planning is decided by strategic generation planners sgps trying to maximize their profits while transmission line investments are planned by a central planner and regulatory body aimed at minimizing the overall operation and network investment costs of the system regulatory transmission charges rtcs are calculated according to the marginal responsibility of generation investment on transmission network investment costs an iterative algorithm is proposed to model the interaction taking place between the central planner and sgps the developed methodology is applied to a 2 node illustrative example and the ieee rts96 and effects of rtcs on investment decisions of sgps are analyzed