fixed production capacity menu cost and the output inflation relationship this paper analyses the impact of inflation when firms face frictions in both price and quantity adjustments a vast literature examines the consequences of price adjustment costs assuming frictionless quantity adjustments however temporary quantity adjustments may be expensive for example because continual adjustments of the optimal production plant are impossible moreover recent findings suggest that frictions in quantity adjustment may remove the linkage between output and inflation in this paper we show that this is not the case when inflation is anticipated on the contrary a predetermined production capacity may significantly amplify the consequences of price adjustment costs

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

inflation costly price and quantity adjustments and time spent in the keynesian regime abstract this paper considers a menu cost firm under inflation due to costly quantity adjustments the firm is sometimes in a keynesian regime where sales are demand determined with a positive real interest rate the proportion of time in the keynesian regime is less than the inverse of the absolute value of the average elasticity of demand in that regime

optimal response of a power generator to energy agc and reserve pool based markets the electric power industry all over the world is undertaking major regulatory and operational changes the understanding of power supply as a public service is being replaced by the notion that competitive markets constitute a more appropriate framework to supply reliable and cheap electric energy to consumers as mandated by ferc orders 888 and 889 this paper considers simultaneously energy agc and reserve markets in a pool framework it provides a tool to enable a power generator to determine optimally its degree of involvement in each one of these markets a real world case study is analyzed and results are presented

optimal operation of a chp plant participating in the german electricity balancing and day ahead spot market abstract during the last years operators of combined heat and power chp plants are challenged by changing circumstances in the electricity markets while ensuring a stable heat and power supply for customers chp plant operators seek to maximise the profitability of the chp plant operation we propose a comprehensive concept and illustrate its potential for increasing the profitability when operating a chp plant with heat storage by participating in multiple electricity markets for this purpose the structure of the decision making process consisting of bid submission market clearing and chp plant operation planning is represented a multistage stochastic mixed integer linear programming milp model is developed that simultaneously optimises the operation of the chp plant with heat storage and bidding in sequential electricity markets price uncertainty is captured by means of stochastic processes the proposed concept is applied to the real case of a municipal energy supply company that participates in the german day ahead spot and balancing market results of the case study illustrate how trading in sequential electricity markets can result in an increased profitability of the chp plant operation where additional revenues from trading offset higher generation costs furthermore we exemplify how the optimal operation of the chp plant and heat storage device are adjusted according to revenue potential in multiple electricity markets

optimal involvement in futures markets of a power producer this paper addresses the optimal involvement in a futures electricity market of a power producer to hedge against the risk of pool price volatility the considered trading horizon spans one whole year recognizing the highly uncertain nature of future pool prices a stochastic programming framework with recourse is used to model this decision making problem the resulting problem is a large scale mixed integer linear programming problem scenario reduction techniques are used to make this problem tractable risk is properly modeled using the cvar methodology results from a realistic case study are provided and analyzed some conclusions are finally drawn

incorporating fuel constraints and electricity spot prices into the stochastic unit commitment problem the electric power industry is going through deregulation as a result the load on the generating units of a utility is becoming increasingly unpredictable furthermore electric utilities may need to buy power or sell their production to a power pool that serves as a spot market for electricity these trading activities expose utilities to volatile electricity prices in this paper we present a stochastic model for the unit commitment that incorporates power trading into the picture our model also accounts for fuel constraints and prices that may vary with electricity prices and demand the resulting model is a mixed integer program that is solved using lagrangian relaxation and bender s decomposition using this solution approach we solve problems with 729 demand scenarios on a single processor to within 0 1 of the optimal solution in less than 10 minutes our numerical results indicate that significant savings can be achieved when the spot market is entered into the problem and when stochastic policy is adopted instead of a deterministic one

hyperbolic discounting and the phillips curve using a standard dynamic general equilibrium model we show that the interaction of staggered nominal contracts with hyperbolic discounting leads to inflation having significant long run effects on real variables

risk constrained generation asset arbitrage in power systems a competitive generating company genco can maximize its payoff by optimizing its generation assets this paper considers the genco s arbitrage problem using stochastic price based unit commitment while considering the associated risks the genco may consider arbitrage opportunities in purchases from qualifying facilities qfs as well as simultaneous trades with spot markets for energy ancillary services fuel and emission allowance the tradeoff between maximizing expected payoffs and minimizing risks due to market price uncertainties is modeled explicitly by including the expected downside risk as a constraint the downside risk is defined as the unfulfilled profit the monte carlo simulation is applied to generate scenarios and scenario reduction techniques are applied to reduce the number of scenarios while maintaining a good approximation of the exact solution the proposed case studies illustrate the significance of arbitrage in multi commodity markets and the importance of considering the uncertainty of market prices

the near optimality of mark up pricing mark up pricing policies result in a loss of profits compared to marginal pricing behavior these losses however are often very small even for large changes in the money supply but by adopting a simple pricing rule the firm does not have to forecast the future and avoids the informational and computational costs required to determine the profit maximizing price each period thus even if these costs are small mark up pricing policies may be optimal or approximately so at least for some firms in a macro model this is likely to imply large monetary non neutralities

output and welfare effects of inflation with costly price and quantity adjustments there exists by now a burgeoning literature concerned with the consequences of a fixed cost of price adjustment due to this cost a monopolistic firm does not necessarily adjust its price even though the current price deviates from the price that would maximize the firm s current profit as a result the production generally differs from what it would be in the absence of a menu cost with the effect of inflation on the average output and welfare under monopolistic competition being ambiguous and depending in a complicated way on the profit and demand functions 1 however one strong result holds unambiguously for all profit and demand functions at low inflation rates the average output and welfare are above their levels at full price stability where firms charge the static monopoly price 2 the driving force is that discounting makes a firm more concerned with its real profits earlier in a period with a constant nominal price than with its real profits later in the period in fact as the inflation rate approaches zero the firm s initial real price converges to the profit maximizing real price while the terminal real price converges to a smaller real price at low inflation rates therefore a firm s price is most of the time below the price that would maximize the current profit since output and welfare under monopolistic competition are inversely related to price average output and welfare are higher than under full price stability the inevitable conclusion is that the economy benefits from a little bit of inflation a critical assumption underlying this result is that firms can continuously adjust their production to satisfy demand so while the menu cost literature explicitly assumes that there is a small fixed cost incurred at each price adjustment it also implicitly assumes that it is costless to continuously adjust the quantity of output 3 this is however a questionable assumption there is some empirical evidence indicating the existence of a cost of quantity adjustment part of which is fixed in that it does not depend on the size of the adjustment 4 the cost of quantity adjustment stems from the need to rearrange and reorganize the factor inputs for the new level of production and includes managerial time and effort a fixed cost of quantity adjustment rules out any continuous adjustment of the production to satisfy the increasing demand that results from a decreasing real price within a period with a constant nominal price under the reasonable assumption that the menu cost does not exceed the fixed cost of quantity adjustment 5 in an inflationary environment a firm chooses to adjust its nomi

on the infrequent adjustment of price by firms i introduction recent research by blinder 1991 indicates that as many as 75 percent of all firms change price no more than twice a year according to the wall street journal these findings seem to have caused considerable surprise 1 there is however nothing unusual about these results infrequent price adjustment by firms can be readily explained by the existence of very small price adjustment or menu costs and the fact that deviations from optimal price adjustment policies often result in negligible reductions in a firm s average rate of profit this paper brings together in a dynamic setting two ingredients in the literature that have previously been linked only in a static framework the small menu cost argument of mankiw 1985 and the near rational argument of akerlof and yellen 1985 numerical examples are used to answer the familiar objection that price adjustment costs are too small to be important the main conclusions of the paper remain valid for a wide variety of plausible parameter values and do not depend on extreme assumptions concerning the flatness of the firm s profit function the basic insight that under imperfect competition first order deviations from optimal behavior imply second order losses was first made by bowley 1924 25 this idea was further developed by akerlof and yellen 1985 since the firm s profit function is flat at its maximum point failure to adjust price in response to small exogenous shocks implies very small losses even if price adjustment is costless if there are some costs associated with changing price a policy of rigid prices in the face of small nominal shocks may be optimal this would seem to provide a micro explanation for sticky prices these ideas are usually expounded in the framework of a static two period model 2 further the conclusions reached are only valid for small deviations from optimal behavior the present paper extends the argument to a dynamic framework of continual inflation and its conclusions are shown to remain valid for large deviations from optimal pricing policies 3 the paper makes two main points first very small price adjustment costs often lead to surprising long intervals between price changes even when the length of this interval is chosen optimally second the loss of profits suffered by the firm when the interval between price changes is much greater than the optimal value is often negligible large deviations from optimal policies typically imply very small losses this is a much stronger claim than the familiar argument that small deviations from optimality imply second order losses and it does not follow from the envelope theorem if a firm adopts a simple rule of say changing price twice a year regardless of the inflation rate it may earn a level of profit practically indistinguishable from that it would earn if it behaved optimally at least for inflation rates experienced in the western democracies since world war ii the standard objection to the menu cost explanation of infrequent price adjustment is that these costs are much too small to explain observed pricing behavior the examples presented below show that this objection can be discounted seemingly trivial price adjustment costs as small as one millionth of the firm s annual revenue can explain price adjustment frequencies as low as once or twice a year at inflation rates of 20 percent per annum and above part of the explanation concerns the flatness of the firm s profit function over a wide range of plausible values of demand and cost parameters profit functions are sufficiently flat to explain observed frequencies of price adjustment even when the interval between price changes is optimal but there is more too it than this large deviations from optimal price adjustment policies imply surprisingly small losses even for profit functions that would never be described as flat in particular the loss in profit caused by large deviations in the interval between price changes from its optimal value are normally very small

a model of the international monetary system we propose a simple model of the international monetary system we study the world supply and demand for reserve assets denominated in different currencies under a variety of scenarios a hegemon vs a multipolar world abundant vs scarce reserve assets a gold exchange standard vs a floating rate system we rationalize the triffin dilemma which posits the fundamental instability of the system as well as the common prediction regarding the natural and beneficial emergence of a multipolar world the nurkse warning that a multipolar world is more unstable than a hegemon world and the keynesian argument that a scarcity of reserve assets under a gold standard or at the zero lower bound is recessionary our analysis is both positive and normative

output effects of inflation with fixed price and quantity adjustment costs i introduction there is convincing evidence that fixed costs of price adjustment may be large levy et al 1997 found such costs to be 0 7 of a firm s revenue and zbaracki et al 2004 found them to be 1 22 in the presence of fixed costs of price adjustment a monopolistic firm does not adjust its nominal price continuously with the result that the real price and output generally deviate from their static monopoly level at low inflation rates the average output is higher than the static monopoly output if there is positive discounting danziger 1988 and depends on higher order derivatives of the profit and demand functions if there is no discounting benabou and konieczny 1994 1 most of the literature assumes that only price adjustments are costly while output can be continuously adjusted without cost however bresnahan and ramey 1994 document that there may be large fixed costs of quantity adjustments relatedly many publications show that adjusting labor and capital inputs involves significant fixed costs 2 such costs may derive from loss of organizational capital baily et al 2001 jovanovic and rousseau 2001 as well as from job protection rules severance pay and legal and administrative complications in a framework with both price and quantity adjustment costs andersen 1995 and andersen and toulemonde 2004 demonstrate that only intermediate size shock but not large or small shocks may affect output for a constant inflation rate danziger 2001 shows that a firm s permanent production decreases with inflation at low inflation rates if discounting is positive and danziger and kreiner 2002 that output capacity decreases with inflation if the elasticity of demand is constant and there is no discounting see also danziger 2003 the purpose of this article is to provide a simple general characterization of the output effects of a constant inflation rate if both price and quantity adjustments involve fixed costs it is assumed that quantity adjustments are at least as costly as price adjustments which implies that a firm s production is held constant at a permanent level 3 each firm then keeps its nominal price unchanged in periods of equal length and the nominal price is adjusted so that the initial real price is the same in each period thus a firm s optimal strategy consists of the initial real price the duration of the periods with unchanged nominal price and the permanent level of production the article shows that in the absence of discounting the effect of inflation on the aggregate production depends on how fast firms marginal real revenue decreases with demand and that this effect is fully determined by the elasticity of the marginal real revenue with respect to demand thus aggregate production decreases with inflation if the elasticity of the marginal real revenue always exceeds minus unity increases with inflation if the elasticity of the marginal real revenue is always less than minus unity and is invariant to inflation if the elasticity of the marginal real revenue always equals minus unity several studies have found that the comovement between output and prices is typically negative in the long run cooley and ohanian 1991 den haan 2000 den haan and sumner 2004 fiorito and kollintzas 1994 within the framework of the present model the negative comovement indicates that the empirically relevant situation is when the elasticity of the marginal real revenue always exceeds minus unity this will be the case among others if demand functions exhibit a constant price elasticity less than minus unity as assumed in danziger and kreiner 2002 ii the model consider an economy with a unit continuum of identical consumers and a unit continuum of monopolistic firms producing differentiated perishable products each firm and its product are indexed by i which is uniformly distributed on 0 1

the optimality of partial price adjustment policies this paper studies the optimal price adjustment policies of a monopolistically competitive firm whose profit maximizing price is subject to a serially correlated random disturbance the firm chooses its price by comparing the expected cost of present and future price changes with the expected losses occurring when price deviates from its instantaneous profit maximizing value partial price adjustment often is the best way to minimize the sum of these losses prices tend to be more flexible both in response to large shocks to the firm s profit maximizing price and when much uncertainty exists about the future

bidding in sequential electricity markets the nordic case abstract for electricity market participants trading in sequential markets with differences in price levels and risk exposure it is relevant to analyze the potential of coordinated bidding we consider a nordic power producer who engages in the day ahead spot market and the hour ahead balancing market in both markets clearing prices and dispatched volumes are unknown at the time of bidding however in the balancing market the market participant faces an additional risk of not being dispatched taking into account the sequential clearing of these markets and the gradual realization of market prices we formulate the bidding problem as a multi stage stochastic program we investigate whether higher risk exposure may cause hesitation to bid into the balancing market furthermore we quantify the gain from coordinated bidding and by deriving bounds on this gain assess the performance of alternative bidding strategies used in practice

money supply variability in a macro model of monopolistic competition the effects of changes in money supply variability are examined for a macro model of monopolistic competition increases in money supply variability raise demand uncertainty causing individual firms to produce more for inventory in addition expected profits decrease inducing a number of firms to leave the economy aggregate income then falls in spite of an increase in firm level production the result on aggregate income is standard but the results on inventories and the number of firms in the economy distinguish this monopolistic macro model empirically from conventional macro models when changes in money supply variability occur

anticipated inflation and aggregate employment the case of costly price adjustment even if inflation is perfectly anticipated a firm that finds nominal price adjustments sufficiently costly will reset its price at multi period intervals consequently its average output will change in a direction that depends on properties of its profit function on the basis of this observation which does not involve money illusion the paper shows that anticipated inflation can stimulate aggregate employment through a process that entails changes in the factor demands of individual monopolistic firms and in the intersectoral allocation of consumer expenditure simulations indicate however that the gain in aggregate employment is likely to be modest

arima models to predict next day electricity prices price forecasting is becoming increasingly relevant to producers and consumers in the new competitive electric power markets both for spot markets and long term contracts price forecasts are necessary to develop bidding strategies or negotiation skills in order to maximize benefit this paper provides a method to predict next day electricity prices based on the arima methodology arima techniques are used to analyze time series and in the past have been mainly used for load forecasting due to their accuracy and mathematical soundness a detailed explanation of the aforementioned arima models and results from mainland spain and californian markets are presented

strong formulations for multistage stochastic self scheduling unit commitment with the increasing penetration of renewable energy into the power grid system the volatility of real time electricity prices increases significantly this brings challenges for independent power producers to provide optimal bidding strategies the traditional approaches of only attending the day ahead market might not be profitable enough without taking advantage of real time price volatility in this paper we study the optimal bidding strategies for the independent power producers utilizing self scheduling strategies to participate in the real time market considering real time electricity price volatility with the objective of maximizing the total expected profit considering the correlations of renewable energy generation outputs among different time periods the correlations of real time prices are captured in our modeling framework in which we explore a multistage stochastic scenario tree to formulate the price uncertainties accordingly the derived multistage stochastic self scheduling unit com

financial intermediation international risk sharing and reserve currencies abstract i model the equilibrium risk sharing between countries with varying financial development the most financially developed country takes greater risks because its financial intermediaries deal with funding problems better in good times the more financially developed country consumes more and runs a trade deficit financed by the higher financial income that it earns as compensation for taking greater risk during global crises it suffers heavier losses its currency emerges as the reserve currency because it appreciates during crises thus providing a good hedge i provide evidence that financial net worth plays a crucial role in understanding this asymmetric risk sharing jel e44 f14 f32 g01 g15 g21

safe u s assets and u s capital flows abstract the exorbitant privilege of the u s the ability of the u s to earn positive net income on its international portfolio even though it is a net debtor may be linked to the convenience yield on u s government bonds the convenience yield refers to the low pecuniary return on u s treasuries associated with the non pecuniary yield on those assets arising from their liquidity and safety a simple model shows how the convenience yield can lead to current account deficits an appreciated currency in real terms and positive net factor income empirically we find evidence associating the convenience yield with a strong dollar in real terms and in turn evidence linking the real exchange rate to the u s current account we calculate that this channel may account for approximately 40 of the u s current account deficit we then discuss factors that might influence the convenience yield and discuss possible drawbacks to the exorbitant privilege

economic impact of electricity market price forecasting errors a demand side analysis several techniques have been proposed in the literature to forecast electricity market prices and improve forecast accuracy however no studies have been reported examining the economic impact of price forecast inaccuracies on forecast users therefore in this paper the application of electricity market price forecasts to short term operation scheduling of two typical and inherently different industrial loads is examined and the associated economic impact is analyzed using electricity market price forecasts as the expected next day electricity prices optimal operating schedules and the associated costs are determined for each load these costs are compared with those of a perfect price forecast scenario in which actual prices are used to determine the operating schedules numerical results and discussions are provided based on price forecasts with different error characteristics

forecasting next day electricity prices by time series models in the framework of competitive electricity markets power producers and consumers need accurate price forecasting tools price forecasts embody crucial information for producers and consumers when planning bidding strategies in order to maximize their benefits and utilities respectively this paper provides two highly accurate yet efficient price forecasting tools based on time series analysis dynamic regression and transfer function models these techniques are explained and checked against each other results and discussions from real world case studies based on the electricity markets of mainland spain and california are presented

economic assessment of concentrated solar power technologies a review abstract this paper surveys economic assessments of concentrated solar power csp technologies and finds two dominant assessment methods a majority of studies reported in the literature are based on the levelized cost of electricity lcoe while a small subset of studies consider time varying meteorological and electricity market conditions several studies argue that lcoe undervalues dynamic flexibility provided by thermal energy storage and does not consider revenue opportunities provided by electricity markets at different time scales as a result some studies find that both lcoe and revenue can in fact be conflicting metrics for certain designs and market conditions this review finds strong variations in lcoe and revenue estimates in the literature as comparisons between csp and other generation technologies e g fossil wind and photovoltaic are dictated by the chosen economic metric it is imperative that policy and investment decisions should carefully consider time varying effects and flexibility finally research directions are proposed to increasing the fidelity of economic assessments and to mitigate discrepancies

the real effects of nominal price rigidity abstract nominal price rigidity may arise from risk spreading contracts and be consistent with fully efficient trade we demonstrate this point by studying the contracts that a risk averse firm signs with its risk neutral supplier and its risk neutral customer before the general price level is publicly revealed there is an equilibrium in which the two contracts specify inflexible prices and efficient quantities

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

inflation output and labour productivity when prices are changed infrequently when prices are changed infrequently the effect of inflation on output depends on the form of profit and demand functions this paper provides a general taxonomy at small inflation rates output falls rises stays the same if the demand function is concave convex linear in terms of the log of real price this holds when the frequency of price changes is fixed in case of a catalogue firm as well as when it is chosen optimally in case of a menu cost firm with fixed and variable price adjustments costs with some specifications inflation increases output but reduces labor productivity copyright 1990 by the london school of economics and political science

multimarket optimal bidding for a power producer this paper considers a profit maximizing thermal producer that participates in a sequence of spot markets namely day ahead automatic generation control agc and balancing markets the producer behaves as a price taker in both the day ahead market and the agc market but as a potential price maker in the volatile balancing market the paper provides a stochastic programming methodology to determine the optimal bidding strategies for the day ahead market uncertainty sources include prices for the day ahead and agc markets and balancing market linear price variations with the production of the thermal producer results from a realistic case study are reported and analyzed conclusions are duly drawn