short term optimal wind power generation capacity in liberalized electricity markets mainly because of environmental concerns and fuel price uncertainties considerable amounts of wind based generation capacity are being added to some deregulated power systems the rapid wind development registered in some countries has essentially been driven by strong subsidizing programs since wind investments are commonly isolated from market signals installed wind capacity can be higher than optimal leading to distortions of the power prices with a consequent loss of social welfare in this work the influence of wind generation on power prices in the framework of a liberalized electricity market has been assessed by means of stochastic simulation techniques the developed methodology allows investigating the maximal wind capacity that would be profitably deployed if wind investments were subject to market conditions only for this purpose stochastic variables determining power prices are accurately modeled a test system resembling the size and characteristics of the german power system has been selected for this study the expected value of the optimal short term wind capacity is evaluated for a considerable number of random realizations of power prices the impact of dispersing the wind capacity over statistical independent wind sites has also been evaluated the simulation results reveal that fuel prices installation and financing costs of wind investments are very influential parameters on the maximal wind capacity that might be accommodated in a market based manner

the electricity generation adequacy problem assessing dynamic effects of capacity remuneration mechanisms abstract following liberalization reforms the ability of power markets to provide satisfactory incentives for capacity investments has become a major concern in particular current energy markets can exhibit a phenomenon of investment cycles which generate phases of under and over capacity and hence additional costs and risks for generation adequacy to cope with these issues new mechanisms called capacity remuneration mechanisms crm have been or will be implemented this paper assesses the dynamic effects of two crms the capacity market and the strategic reserve mechanism and studies to what extent they can reduce the investment cycles generation costs and shortage costs of both mechanisms are also compared to conclude on their effectivity and economic efficiency a simulation model based on system dynamics is developed to study the functioning of both crms and the related investment decisions the results highlight the benefits of deploying crms to solve the adequacy issue shortages are strongly reduced compared to an energy only market besides the capacity market appears to be more beneficial since it experiences fewer shortages and generation costs are lower these comparisons can be used by policy makers in particular in europe where these two crms are mainly debated to determine which crm to adopt

a review of policy analysis purpose and capabilities of electricity system models abstract the aim of this study is to investigate the ability of electricity system models to provide scenario based insights for policy purposes a framework is built from a review of existing studies of model characteristics and their linkages to model scenario types which are linked to the purpose of policy problem analyses the framework can be used as a tool to structure the examination of electricity system models and guide electricity system model selection and enhancement in light of policy problem driven analyses an illustration of the framework is presented by a review of german electricity model scenario studies the review shows that current models are used for the policy purpose of indicator assessment and instrument comparison by quantification of indicators such as monetary or pollution impacts however they are not suitable to provide the means for option reduction problem exploration and political or societal paradigm change exploration as the endogenous model structure for these is missing a particular lack of endogenous treatment was found for renewable technology capacity change and policies learning and productivity growth based technological change socio political technical interactions and limited demonstrated use of uncertainty treatment techniques

germany s dash for coal exploring drivers and factors abstract the german electricity sector has recently seen extensive planning and construction of new coal fired power plants within a period of only a few years new investments amounting to around 15 of the total sector capacity were brought on the way and plans for a multitude of additional projects are pending this dash for coal in germany has raised considerable public concern especially as it risks to undermine recent political attempts to combat global warming yet the question of why the dash for coal has emerged has not yet been addressed in a thorough analysis this article attempts to close this research gap while at the same time contributing as a case study to the general understanding of investment patterns in liberalized electricity markets it finds that the main reasons for the dash have been 1 replacement requirements due to the nuclear phase out 2 the onset of a new investment cycle in the power market 3 favorable economic and technological prospects for coal compared with natural gas in the long run 4 a status quo bias of investors in regard to future renewable deployment 5 explicit political support for coal and 6 the ineffectiveness of public protest in hampering new projects

effects of a hybrid price stock dependent demand on the optimal solutions of a deteriorating inventory system and trade credit policy on re manufactured product abstract this study contributes to formulate a deteriorating inventory model with a hybrid price stock dependent demand with credit for units in stock period in the presence of trade credit policy by using the discounted cash flow approach on re manufactured products in real life the demand function is not always constant or linear or nonlinear the demand rate of any items goes up and down in the real market due to the sum of two different types of demand this study observes that the demand is depending on price and stock of the product time value of money and trade credit policy the objective of this study is to find optimum cycle time optimum selling price and present profit of all future cash flows the model starts with mathematical formulating and thereafter studies the necessary and sufficient conditions for obtaining the unique optimal solution the theoretical solution procedure and case examples have studied for validation of this model moreover the sensitivity analysis is expressed out with respect to main parameters and managerial application is obtained this study uses the different demand functions of a simple pricing inventory system to find out the maximum profit on re manufactured products

social networks and the process of globalization we propose a stylised dynamic model to understand the role of social networks in the phenomenon we call globalization this term refers to the process by which even agents who are geographically far apart come to interact thus being able to overcome what would otherwise be a fast saturation of local opportunities a key feature of our model is that the social network is the main channel through which agents exploit new opportunities therefore only if the social network becomes global heuristically it reaches far in few steps can global interaction be steadily sustained to shed light on the conditions under which such a transformation may or may not take place is the main objective of the paper one of the main insights arising from the model is that in order for the social network to turn global the economy needs to display a degree of geographical cohesion that is neither too high for then global opportunities simply do not arise nor too low then the meeting mechanism displays too little structure for the process to take off but if globalization does materialize we show that it is a robust state of affairs that often arises abruptly as key parameters change this occurs in particular as the rate of arrival of ideas rises or when there is a high enough increase in the range at which the network transmits information

the dynamics of the uk chemical plant investment cycle abstract orders for new chemical plant sanctions and investment in chemical plant both show marked business cycle like variations amongst the effects of the uk cycle on the chemical industry are variations in new plant additions requirements for capital expenditure finance and capital utilization as far as the uk process plant contractors and process plant manufacturers are concerned the cycle is reflected in a varying work load arising from the uk chemical industry together with varying manpower requirements and profitability the project described in this paper involved the construction of both system dynamics and control systems models of the investment cycle as a guide to strategic planning for the industries affected by it the implications of the results from both types of model for corporate and strategic planning in the industries concerned are discussed

building up social capital in a changing world this paper models the dynamic process through which a large society may succeed in building up its social capital by establishing a stable and dense pattern of interaction among its members in the model agents interact according to a collection of idyosincratic infinitely repeated prisoner s dilemma played on the existing social network this network not only specifies the playing partners but crucially also determines how relevant strategic information diffuses or new cooperation opportunities are found over time the underlying payoffs randomly change i e display some volatility in response to it agents react by creating new links and removing others this combines into a complex but ergodic dynamic process whose analysis is undertaken in different ways first we rely on its ergodicity to compute numerically its long run regularities second we use mean field approximations to derive analytical results both routes are found in accord and also complementary the long run dynamics of the process sharply depends on environmental volatility displaying the following features a only if volatility is not too high can the society sustain a dense social network and thus attain a large average payoff b the social architecture endogenously responds to increased volatility by becoming more cohesive c network based strategic effects are an essential buffer that preclude the abrupt collapse of the social network in the face of growing volatility these conclusions are largely in tune with the points stressed in the social capital literature

an eoq model for perishable products with fixed shelf life under stochastic demand conditions abstract the paper presents a mathematical stochastic model for perishable open dating foods including shortage and outdating costs the demand fluctuations have been taken into account modeling them through a normal distribution and their impact on the storage time has been studied considering the stochastic nature of such a parameter in turn the quantification of perished products has been also addressed determining the probability for a product of remaining in stock beyond the end of its shelf life on the basis of such premises the optimal set of parameters that minimize the total unit cost has been determined a numerical application and a sensitivity analysis show the practical applicability of the proposed model in the context of warehouse management underlining managerial insights

measuring globalization of international trade theory and evidence summary measuring globalization requires a standard of perfect international integration as a benchmark that a single world space would reach under conditions of geographic neutrality in international trade we define this standard and present indicators for openness connectedness and integration for each specific economy and for the world economy we apply our indicators to data on trade flows for 59 countries for the 1967 2004 period results show that trade integration is higher than what traditional openness indicators suggest several economies find high levels of integration but the low degree of openness in some large economies jeopardizes the progress of globalization

a note on optimal replenishment policies for non instantaneous deteriorating items with price and stock sensitive demand under permissible delay in payment abstract soni 2013 int j prod econ 146 1 259 268 proposed optimal replenishment policies for non instantaneous deteriorating items i e the product starts deteriorating after a period of no deterioration with price and stock sensitive demand with a stock dependent demand it is desirable to have non zero ending inventory due to potential profit resulting from the increased demand however soni 2013 int j prod econ 146 1 259 268 treated those ending inventory as fresh stocks to go through another period of non deterioration again additionally he assumed for simplicity that the replenishment cycle time t must be longer than the period of non deterioration t d i e t t d in reality one should consider all possible replenishment cycle time to maximize the profit in this note we complement the shortcomings of his model by i selling those ending inventory as salvages and ii considering all possible replenishment cycle time which may be shorter than the period of non deterioration with these modifications the repeatability of the replenishment cycle is ensured and the applicability of soni s model is strengthened the numerical examples indicate that the global optimal solution is indeed possible in the case of t t d

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

exploring the options for carbon dioxide mitigation in turkish electric power industry system dynamics approach electric power industry has a huge carbon mitigation potential fundamentally because there are large carbon free renewable resource options in turkey with growing demand in electricity consumption and incentives offered for natural gas fired electricity generation co2 emissions sourced from electric power industry had tripled over the last two decades current governmental strategy focuses on energy security and resource diversity in a growing economy and does not articulate sufficient mitigation targets and appropriate regulations in this research an original dynamic simulation model is built validated and analyzed to explore the options for carbon mitigation in turkish electric power industry model structure represents the investment dispatch and pricing heuristics as well as the natural resource base of electricity generation in turkey it operates on annual basis over 30 years to simulate installed capacities and generations of power plants with alternative resources and their resulting co2 emissions the analysis presented in this paper reveals that there are mitigation options below 50 of business as usual growth with common policy options such as feed in tariffs investment subsidies and carbon taxes the model can serve as an experimental platform for further analysis of problems related to carbon mitigation in turkish electricity sector

modeling long term dynamics of electricity markets in the last decade many countries have restructured their electricity industries by introducing competition in their power generation sectors although some restructuring has been regarded as successful the short experience accumulated with liberalized power markets does not allow making any founded assertion about their long term behavior long term prices and long term supply reliability are now center of interest this concerns firms considering investments in generation capacity and regulatory authorities interested in assuring the long term supply adequacy and the stability of power markets in order to gain significant insight into the long term behavior of liberalized power markets in this paper a simulation model based on system dynamics is proposed and the underlying mathematical formulations extensively discussed unlike classical market models based on the assumption that market outcomes replicate the results of a centrally made optimization the approach presented here focuses on replicating the system structure of power markets and the logic of relationships among system components in order to derive its dynamical response the simulations suggest that there might be serious problems to adjust early enough the generation capacity necessary to maintain stable reserve margins and consequently stable long term price levels because of feedback loops embedded in the structure of power markets and the existence of some time lags the long term market development might exhibit a quite volatile behavior by varying some exogenous inputs a sensitivity analysis is carried out to assess the influence of these factors on the long run market dynamics

redistribution effects of energy and climate policy the electricity market abstract energy and climate policies are usually seen as measures to internalize externalities however as a side effect the introduction of these policies redistributes wealth between consumers and producers and within these groups while redistribution is seldom the focus of the academic literature in energy economics it plays a central role in public debates and policy decisions this paper compares the distributional effects of two major electricity policies support schemes for renewable energy sources and co2 pricing we find that the redistribution effects of both policies are large and they work in opposed directions while renewables support transfers wealth from producers to consumers carbon pricing does the opposite more specifically we show that moderate amounts of wind subsidies can increase consumer surplus even if consumers bear the subsidy costs co2 pricing in contrast increases aggregated producer surplus even without free allocation of emission allowances however not all types of producers benefit these findings are derived from an analytical model of electricity markets and a calibrated numerical model of northwestern europe our findings imply that if policy makers want to avoid large redistribution they might prefer a mix of policies even if co2 pricing alone is the first best climate policy in terms of allocative efficiency

does globalization affect growth evidence from a new index of globalization the study develops an index of globalization covering its three main dimensions economic integration social integration and political integration using panel data for 123 countries in 1970 2000 it is analysed empirically whether the overall index of globalization as well as sub indexes constructed to measure the single dimensions affect economic growth as the results show globalization indeed promotes growth the dimensions most robustly related with growth refer to actual economic flows and restrictions in developed countries although less robustly information flows also promote growth whereas political integration has no effect

effect of floating pricing policy an application of system dynamics on oil market after liberalization abstract upon the implementation of the floating price mechanism taiwan s gasoline and diesel prices returned to market mechanism which terminated the phenomenon of the public paying for the losses of the state owned oil company chinese petroleum corporation taiwan cpc furthermore the relatively low production costs of the privately owned formosa petrochemical corporation fpcc disclosed the pricing mechanism of cpc which inspired fpcc to adopt pricing strategy in order to increase the market share this study aims to establish a system dynamics model to analyze the effects of the floating price mechanism on taiwan s gasoline and diesel markets this model is divided into four sub systems the model of this study passed several validation tests and hence is able to provide a virtual laboratory for policy makers to conduct simulation and scenario analysis the simulation results indicate a feedback mechanism of expected revenues and pricing strategy could efficiently simulate the fpcc pricing mechanism b price competition strategy could increase fpcc revenues although the effect on market share is not remarkable and c fpcc has a higher gas station growth rate scenario analyses found a lowering oil security stockpile would not change fpcc s pricing strategy and b fpcc prefers to follow cpc pricing when it has more gas stations

generation capacity adequacy in interdependent electricity markets this paper deals with the practical problems related to long term security of supply in regional electricity markets with transmission constraints differences between regulatory policies and market designs in terms of generation adequacy policies may distort the normal functioning of the neighboring markets as well as the reliability of supply we test the effect of heterogeneous regulatory design between two interdependent markets energy only market price capped market without capacity mechanisms and price capped markets with forward capacity contracts obligation we rely on a long term market simulation model in system dynamics that characterizes expansion decision in a competitive regime the results show that differences in market designs affect both price and reliability of supply in the two markets we examine both the short and long terms effect and how free riding may occur where capacity adequacy policies are adopted in one market but not the other the main finding is that the lack of harmonization between local markets in policies to ensure capacity adequacy may lead to undesirable side effects

dynamic modeling of thermal generation capacity investment application to markets with high wind penetration modeling the dynamics of merchant generation investment in market environments can inform the making of policies whose goals are to promote investment in renewable generation while maintaining security of supply such models need to calculate expected output costs and revenue of thermal generation subject to varying load and random generator outages in a power system with high penetrations of wind this paper presents a dynamic investment simulation model where the short term energy market is simulated using probabilistic production costing using the mix of normals distribution mond technique to represent residual load load net of wind output price mark ups due to market power are accounted for an energy only market setting is used to estimate the economic profitability of investments and forecast the evolution of security of supply simulated results for a great britain gb market case study show a pattern of increased relative security of supply risk during the 2020s in addition many new investments can recover their fixed costs only during years in which more frequent supply shortages push energy prices higher

social norms and random matching games abstract nash equilibrium has been tremendously useful in understanding economic problems in which strategic behavior is important the theoretical foundations of the solution concept often include the assumption that the game to be played is common knowledge an unrealistic assumption in games with many players we introduce the concept of norm equilibrium for random matching games a norm equilibrium is a nash equilibrium that relies on substantially less information than common knowledge of the game we use norm equilibria to provide a folk theorem for random matching games and to analyze increasing numbers of players in a random matching game journal of economic literature classification numbers c70 c72

ostracism and forgiveness many communities rely upon ostracism to enforce cooperation if an individual shirks in one relationship her innocent neighbors share information about her guilt in order to shun her while continuing to cooperate among themselves however a strategic victim may herself prefer to shirk rather than report her victimization truthfully if guilty players are to be permanently ostracized then such deviations are so tempting that cooperation in any relationship is bounded by what the partners could obtain through bilateral enforcement ostracism can improve upon bilateral enforcement if tempered by forgiveness through which guilty players are eventually readmitted to cooperative society

an inventory system with demand dependent on both time and price assuming backlogged shortages abstract in this work we analyze an inventory model for items whose demand is a bivariate function of price and time it is supposed that the demand rate multiplicatively combines the effects of a time power function and a price logit function the aim is to maximize the profit per time unit assuming that the inventory cost per time unit is the sum of the holding shortage ordering and purchasing costs an algorithm is developed to find the optimal price the optimal lot size and the optimal replenishment cycle several numerical examples are introduced to illustrate the solution procedure

what are the right policies for electricity supply in middle east a regional dynamic integrated electricity model for the province of yazd in iran energy planning techniques are essential tools in the management of new complex energy systems among different techniques system dynamics is an appropriate technique for the simulation of complex energy systems and the analysis of their dynamism in this paper a regional dynamic integrated electricity model rdiem is developed for a regulated electricity supply system in order to analyze the results of different scenarios and policies and find the right policies for the electricity generation the results of model are validated with a real case in the province of yazd in iran the results show that the balanced growth and the environment oriented policies have the best results among different policies although the application is related to the iranian case the implications are much wider especially in the middle east

the impact of investors risk aversion on the performances of capacity remuneration mechanisms abstract this paper analyses the impact of risk aversion on the performances of capacity remuneration mechanisms with investors facing an uncertain peak load three market designs are studied for this purpose a competitive energy only market a capacity market and a strategic reserve mechanism a simulation model based on system dynamics is developed in order to represent investment decisions and analyse the behaviour of each market design risk aversion is modelled through the computation of conditional value at risk the results are discussed in terms of impact on the reliability ability to limit shortages and cost total generation costs of the studied market designs when comparing the three market designs the capacity market seems to be the least affected by the introduction of risk aversion both in terms of cost and reliability this result suggests that implementing a capacity market is preferable in order to deal with the adverse effects of risk aversion given the simulations and parameters that were used

a real options evaluation model for the diffusion prospects of new renewable power generation technologies this study presents a policy planning model that integrates learning curve information on renewable power generation technologies into a dynamic programming formulation featuring real options analysis the model recursively evaluates a set of investment alternatives on a year by year basis thereby taking into account that the flexibility to delay an irreversible investment expenditure can profoundly affect the diffusion prospects of renewable power generation technologies price uncertainty is introduced through stochastic processes for the average wholesale price of electricity and for input fuel prices demand for electricity is assumed to be increasingly price sensitive as the electricity market deregulation proceeds reflecting new options of consumers to react to electricity price changes such as time of use pricing unbundled electricity services and choice of supplier the empirical analysis is based on data for the turkish electricity supply industry apart from general implications for policy making it provides some interesting insights about the impact of uncertainty and technical change on the diffusion of various emerging renewable energy technologies

cycles in deregulated electricity markets empirical evidence from two decades abstract in this article we discuss the cycle hypothesis in electricity generation which states that the introduction of deregulation in an electricity system might lead to sustained fluctuations of over and under capacity the occurrence of cycles is one of the major threats for electricity markets as it affects the security of supply and creates uncertainty in both the profitability of electricity companies and in consumer prices we discuss the background for these cycles using analogies with other capital intensive industries along with evidence from the analysis of behavioral simulation models as well as from experimental electricity markets using data from the oldest deregulated markets we find support for the hypothesis in the case of the english and chilean markets based on an autocorrelation analysis evidence from the nordpool market is more ambiguous although we might be observing the first half of a cycle in generation capacity comparing a simulation of the english market performed in 1992 with the actual performance we can observe that the qualitative behavior of the model is consistent with the actual evolution finally we discuss possible mechanisms for damping cycles in electricity generation such as mothballing capacity payments and reliability markets

a capacity investment model of wind power with uncertain supply price under high penetration rate abstract with the rapid development of renewable energy the proportion of wind power in power supply has grown significantly also it influences the power price fluctuation since the marginal cost of wind power is almost zero the growth of wind power s penetration rate has led to a crowding out effect and challenged traditional power generation technology substantially reducing the power price in the market in perfect competition market the real time balance between supply and demand of power is regulated by the real time power price fluctuation so this paper models the intermittence of wind power as uncertain supply and develops a capacity investment model under the uncertainties of both supply and demand we introduce priority dispatch elasticity to describe the crowding out effect and take the power price to be endogenous in order to model the situation of high penetration rate we compare the optimal wind power capacity decision under the strategy of priority grid connection and abandoned power management our results show that optimal capacity investment is inversely related to priority dispatch elasticity under both strategies however the profit from power generation is always higher when adopting the abandoned power management strategy

structural analysis of manufacturer pricing in the presence of a strategic retailer consumer goods manufacturers usually sell their brands to consumers through common independent retailers theoretical research on such channel structures has analyzed the optimal behavior of channel members under alternative assumptions of manufacturer retailer interaction vertical strategic interaction research in empirical industrial organization has focused on analyzing the competitive interactions between manufacturers horizontal strategic interaction decision support systems have made various assumptions about retailer pricing rules e g constant markup category profit maximization the appropriateness of such assumptions about strategic behavior for any specific market however is an empirical question this paper therefore empirically infers 1 the vertical strategic interaction vsi between manufacturers and retailer 2 the horizontal strategic interaction hsi between manufacturers simultaneously with the vsi and 3 the pricing rule used by a retailer the approach is particularly appealing because it can be used with widely available scanner data where there is no information on wholesale prices researchers usually have no access to wholesale prices even manufacturers who have access to their own wholesale prices usually have limited information on competitors wholesale prices in the absence of wholesale prices we derive formulae for wholesale prices using game theoretic solution techniques under the specific assumptions of vertical and horizontal strategic interaction and retailer pricing rules we then embed the formulae for wholesale prices into the estimation equations while our empirical illustration is using scanner data without wholesale prices the model itself can be applied when wholesale prices are available early research on the inference of hsi among manufacturers in setting wholesale prices using scanner data e g kadiyali et al 1996 1999 made the simplifying assumption that retailers charge a constant margin this assumption enabled them to infer wholesale prices and analyze competitive interactions between manufacturers in this paper we show that this model is econometrically identical to a model that measures retail price coordination across brands hence the inferred cooperation among manufacturers could be exaggerated by the coordinated pricing category management done by the retailer we find empirical support for this argument this highlights the need to properly model and infer vsi simultaneously to accurately estimate the hsi when using data at the retail level functional forms of demand have been evaluated in terms of the fit of the model to sales data but recent theoretical research on channels lee and staelin 1997 tyagi 1999 has shown that the functional form has serious implications for strategic behavior such as retail passthrough while the logit and linear model implies equilibrium passthrough of less than 100 lee and staelin call this vertical strategic substitute vss the multiplicative model implies optimal passthrough of greater than 100 vertical strategic complement vsc because passthrough rates on promotions have been found to be below or above 100 chevalier and curhan 1976 armstrong 1991 we empirically test the appropriateness of the logit vss and the multiplicative vsc functional form for the data we perform our analysis in the yogurt and peanut butter categories for the two biggest stores in a local market we found that the vss implications of the logit fit the data better than the multiplicative model we also find that for both categories the best fitting model is one in which 1 the retailer maximizes category profits 2 the vsi is manufacturer stackelberg and 3 manufacturer pricing hsi is tacitly collusive the fact that the retailer maximizes category profits is consistent with theoretical expectations the inference that the vsi is manufacturer stackelberg reflects the institutional reality of the timing of the game retailers set their retail prices after manufacturers set their wholesale prices note that in the stores and product categories that we analyze the two manufacturers own the dominant brands with combined market shares of about 82 in the yogurt market and 65 in the peanut butter market the result is also consistent with a balance of power argument in the literature the finding that manufacturer pricing is tacitly collusive is consistent with the argument that firms involved in long term competition in concentrated markets can achieve tacit collusion managers use decision support systems for promotion planning that routinely make assumptions about vsi hsi and the functional form the results from our analysis are of substantive import in judging the appropriateness of assumptions made in such decision support systems

the architecture of globalization a network approach to international economic integration we combine data on international trade linkages with network methods to examine the global trading system as an interdependent complex network we map the topology of the international trade network and suggest new network based measures of international economic integration at both a global system wide level and a local country level we develop network based measures that incorporate not only the volume of trade but also the influence that a country has on the international trading system these measures incorporate the structure and function of the network and may provide a more meaningful approach to globalization than current measures based on trade volumes we find that in terms of participation and influence in the network global trade is hierarchical with a core periphery structure at higher levels of trade though integration of smaller countries into the network increased considerably over the 1990s the network is strongly balkanized according to geography of trading partners but not as strongly by income or legal origin using these new measures we find that a country s position in the network has substantial implications for economic growth we therefore suggest that a network approach to international economic integration has potential for useful applications in international business finance and development

rational entry into risky markets with negative expected returns the role of biased misestimation of profit potential abstract we extend the theory of negative long run profits in risky industries by incorporating a negatively skewed profit distribution rational behavior with incomplete information is introduced by allowing economic agents to know the median rather than the mean rate of return we compare this to the case involving postdecision bolstering where entrants choose to discount available information on the industry profit distribution monte carlo experiments are tailored to the experience of the u s home building industry

sensitivity of reserve margin to factors influencing investment behaviour in the electricity market of england and wales abstract the electricity generation and distribution industries of england and wales have recently undergone major re structuring as part of the privatization process of taking them out of the public sector on the generation side three major companies have been created which compete both with each other and with the new independent companies who are expected to enter the market trading between generators and distributors is controlled centrally by a pool system which attempts to ensure the optimal operation of the system in the short term and gives a pricing signal for longer term investment this pricing signal depends upon an a priori loss of load probability this paper is intended to provide insights into how the investment in capacity for generation could evolve according to various regulatory conditions economic assumptions degrees of competition and the strategic behaviour of the separate companies using a system dynamics approach a simulation model of investment is developed to generate insights into the volatility of the reserve margin variations in the loss of load probability and the various market share scenarios the degree of uncertainty in the demand the amount of information exchange between competitors and the degree of foresight in planning are considered as well as different financial or market share objectives for companies

optimal ordering and pricing policy for demand functions that are separable into price and inventory age abstract we formulate and analyze two models for determining the optimal pricing order quantity and replenishment period for items whose demand function is separable into components of price and inventory age the first model assumes a multiplicative demand function we provide conditions which are satisfied by most common price dependent demand functions to reduce the three variable profit maximization problem into a single variable problem which can be solved using an efficient line search method next we show that a genuine additive model cannot exist and instead suggest and analyze a pseudo additive model however this model is more limited than the multiplicative model in its ability to incorporate various combinations of price and inventory age effects and reduction of the maximization problem into a single variable problem is more complicated except in the case of a linear price effect which is further analyzed for both models we show that the optimal solution satisfies the first order condition for equilibrium under a monopoly with a modification that includes inventory holding costs we solve numerical examples to illustrate the solution procedures

simulating the new british electricity market reform abstract the british government is implementing fully its novel electricity market reform gb emr its objective in line with european directives aims at replacing existing nuclear and coal plant with low carbon systems to deliver reliable and affordable power though the gb emr has proposed several policy instruments for meeting its objectives and the academic literature has discussed the main issues no known report includes a comprehensive and dynamic simulation exercise that assesses the extent of this profound and important initiative this paper presents a system dynamics model that supports analysis of long term effects of the various policy instruments that have been proposed in the gb emr focusing on environmental quality security of supply and economic sustainability using lessons learned from simulation the paper concludes that effectively achieving the gb emr objectives requires this comprehensive intervention or a similar one that includes the promotion of low carbon electricity generation through the simultaneous implementation of various direct and indirect incentives such as a carbon price floor a feed in tariff fit and a capacity mechanism

fuel mix diversification incentives in liberalized electricity markets a mean variance portfolio theory approach monte carlo simulations of gas coal and nuclear plant investment returns are used as inputs of a mean variance portfolio optimization to identify optimal base load generation portfolios for large electricity generators in liberalized electricity markets we study the impact of fuel electricity and co2 price risks and their degree of correlation on optimal plant portfolios high degrees of correlation between gas and electricity prices as observed in most european markets reduce gas plant risks and make portfolios dominated by gas plant more attractive long term power purchase contracts and or a lower cost of capital can rebalance optimal portfolios towards more diversified portfolios with larger shares of nuclear and coal plants

the effect of long term expansion on the evolution of electricity price numerical analysis of a theoretically optimised electricity market abstract a decision support tool is proposed for optimising the expansion planning of a semi liberalised electricity market whilst the underlying interaction of the generating mix with electricity prices is researched in the long run a nonlinear stochastic programming algorithm is used for handling multiple uncertainties optimising the power sector characteristics both in terms of financial and environmental performance two endogenous models and an exogenous one are analysed and compared the endogenous model results indicate that consumers might benefit by the moderate electricity prices in case the optimal loads and capacity orders are rendered the exogenous model is insensitive to generating mix variations the long term actions suggested for system operators are comprised of the permits issued for new entries they are affected by the evolution of electricity prices since the permits granted for conventional technologies are maintained when their profits are rising the permits granted for renewable technologies are also maintained thus allowing cleaner electricity production to be induced to the grid the optimal bid strategies of generators interact with their dispatching schedule and the diversification of their load curves the relevant bids are primarily driven by the merit order the plants are dispatched in the assigned load levels may be raised in profitable producers so that their profit is maximised they might be restrained instead in case there are no significant prospects for individual profits the lognormal distribution of electricity price results is characterised by increasing variance over time indicating that the model is more robust in the most imminent solutions

an elasticity approach to the newsvendor with price sensitive demand we introduce a measure of elasticity of stochastic demand called the elasticity of the lost sales rate which offers a unifying perspective on the well known newsvendor with pricing problem this new concept provides a framework to characterize structural results for coordinated and uncoordinated pricing and inventory strategies concavity and submodularity of the profit function as well as sensitivity properties of the optimal inventory and price policies are characterized by monotonicity conditions or bounds on the elasticity of the lost sales rate these elasticity conditions are satisfied by most relevant demand models in the marketing and operations literature our results unify and complement previous work on price setting newsvendor models and provide a new tool for researchers modeling stochastic price sensitive demand in other contexts

social capital and social quilts network patterns of favor exchange we examine the informal exchange of favors in societies such that any two individuals interact too infrequently to sustain exchange but such that the social pressure of the possible loss of multiple relationships can sustain exchange patterns of exchange that are locally enforceable and renegotiation proof necessitate that all links are supported any two individuals exchanging favors have a common friend in symmetric settings such robust networks are social quilts tree like unions of completely connected subnetworks examining favor exchange networks in 75 villages in rural india we find high levels of support and identify characteristics that correlate with support

trade expansion and contract enforcement consider a world of traders separated in geographic economic or social space honest trade offers larger gains for more distant traders but frequencies of meetings and information flows about cheating have local bias honesty is self enforcing only between pairs of sufficiently close neighbors global honesty prevails only in a sufficiently small world the extent of self enforcing honesty is likely to decrease when the world expands beyond this size costly external enforcement is useful only if the world is sufficiently large and its net payoff need not be larger than that of a self governing small community intermediate size worlds fare worst

on the behavioral and rational foundations of economic dynamics abstract existing uncertainties about the correct explanations for economic growth and business cycles cannot be settled by aggregative analysis within the neoclassical framework current disputes in theory rest largely on ad hoc casually empirical assumptions about departures from perfect rationality under uncertainty such disputes can only be settled by painstaking microeconomic empirical study of human decision making and problem solving microeconomic research of the kinds that are required can receive powerful guidance from the theories of human thinking that have been developed and tested over the past twenty five years by cognitive psychologists

trust and social collateral this paper builds a theory of trust based on informal contract enforcement in social networks in our model network connections between individuals can be used as social collateral to secure informal borrowing we define network based trust as the largest amount one agent can borrow from another agent and derive a reduced form expression for this quantity which we then use in three applications 1 we predict that dense networks generate bonding social capital that allows transacting valuable assets whereas loose networks create bridging social capital that improves access to cheap favors such as information 2 for job recommendation networks we show that strong ties between employers and trusted recommenders reduce asymmetric information about the quality of job candidates 3 using data from peru we show empirically that network based trust predicts informal borrowing and we structurally estimate and test our model

the market value of variable renewables the effect of solar wind power variability on their relative price this paper provides a comprehensive discussion of the market value of variable renewable energy vre the inherent variability of wind speeds and solar radiation affects the price that vre generators receive on the market market value during windy and sunny times the additional electricity supply reduces the prices because the drop is larger with more installed capacity the market value of vre falls with higher penetration rate this study aims to develop a better understanding on how the market value with penetration and how policies and prices affect the market value quantitative evidence is derived from a review of published studies regression analysis of market data and the calibrated model of the european electricity market emma we find the value of wind power to fall from 110 of the average power price to 50 80 as wind penetration increases from zero to 30 of total electricity consumption for solar power similarly low value levels are reached already at 15 penetration hence competitive large scale renewable deployment will be more difficult to accomplish than as many anticipate

cross border electricity market effects due to price caps in an emission trading system an agent based approach the recent low co2 prices in the european union emission trading scheme eu ets have triggered a discussion whether the eu ets needs to be adjusted we study the effects of co2 price floors and a price ceiling on the dynamic investment pathway of two interlinked electricity markets loosely based on great britain which already has introduced a price floor and on central western europe using an agent based electricity market simulation with endogenous investment and a co2 market including banking we analyse the cross border effects of national policies as well as system wide policy options a common moderate co2 auction reserve price results in a more continuous decarbonisation pathway this reduces co2 price volatility and the occurrence of carbon shortage price periods as well as the average cost to consumers a price ceiling can shield consumers from extreme price shocks these price restrictions do not cause a large risk of an overall emissions overshoot in the long run a national price floor lowers the cost to consumers in the other zone the larger the zone with the price floor the stronger the effect price floors that are too high lead to inefficiencies in investment choices and to higher consumer costs

dynamic analysis of various investment incentives and regional capacity assignment in iranian electricity market this paper develops a system dynamics model to analyze the impacts of different kinds of capacity payment as investment incentive mechanisms in iranian electricity market since it is aimed that the incurred capital and operating costs of generation technologies be recovered in iranian electricity pool the noncompetitive capacity payment mechanism has been introduced for this purpose in order to encourage new investments in electric power generation system in the current mechanism the capacity payments are designated to the generating units in the whole country electricity market an annual base value of capacity payment is proposed based on recovering the capital cost of a benchmark generation technology this value is altered according to the operational reserve in the day ahead electricity market this supporting policy is simulated and analyzed in the proposed dynamic framework in order to track the trend of new investments in the iranian electricity market the feasibility study of implementing the regional capacity assignment is the main focus of this paper different possible regulating policies such as floating rates for capacity payment and electricity price cap the multiple capacity payments to various technologies and the regional electricity market with territorial capacity allocation are examined in order to investigate the consequences and performances of different decisions and policies in the capacity investment of iranian electricity market

classification of future electricity market prices forecasting short term electricity market prices has been the focus of several studies in recent years although various approaches have been examined achieving sufficiently low forecasting errors has not been always possible however certain applications such as demand side management do not require exact values for future prices but utilize specific price thresholds as the basis for making short term scheduling decisions in this paper classification of future electricity market prices with respect to pre specified price thresholds is introduced two alternative models based on support vector machines are proposed in a multi class multi step ahead price classification context numerical results are provided for classifying prices in ontario s and alberta s markets

the external wealth of nations measures of foreign assets and liabilities for industrial and developing countries abstract although capital flows are closely monitored surprisingly little is known about the accumulated stocks of foreign assets and liabilities held by various countries especially in the developing world this paper constructs estimates of foreign assets and liabilities and their equity and debt subcomponents for a sample of 67 industrial and developing countries it characterizes the stylized facts of international balance sheets and asks whether there are trends in net foreign asset positions and shifts in debt equity ratios over time finally it explores the sensitivity of estimated stock positions to the treatment of valuation effects not captured in balance of payments data

sustainable energy systems role of optimization modeling techniques in power generation and supply a review electricity is conceivably the most multipurpose energy carrier in modern global economy and therefore primarily linked to human and economic development energy sector reform is critical to sustainable energy development and includes reviewing and reforming subsidies establishing credible regulatory frameworks developing policy environments through regulatory interventions and creating market based approaches energy security has recently become an important policy driver and privatization of the electricity sector has secured energy supply and provided cheaper energy services in some countries in the short term but has led to contrary effects elsewhere due to increasing competition resulting in deferred investments in plant and infrastructure due to longer term uncertainties on the other hand global dependence on fossil fuels has led to the release of over 1100 gtco2 into the atmosphere since the mid 19th century currently energy related ghg emissions mainly from fossil fuel combustion for heat supply electricity generation and transport account for around 70 of total emissions including carbon dioxide methane and some traces of nitrous oxide this multitude of aspects play a role in societal debate in comparing electricity generating and supply options such as cost ghg emissions radiological and toxicological exposure occupational health and safety employment domestic energy security and social impressions energy systems engineering provides a methodological scientific framework to arrive at realistic integrated solutions to complex energy problems by adopting a holistic systems based approach especially at decision making and planning stage modeling and optimization found widespread applications in the study of physical and chemical systems production planning and scheduling systems location and transportation problems resource allocation in financial systems and engineering design this article reviews the literature on power and supply sector developments and analyzes the role of modeling and optimization in this sector as well as the future prospective of optimization modeling as a tool for sustainable energy systems

capacity adequacy in power markets facing energy transition a comparison of scarcity pricing and capacity mechanism this article analyses how a capacity mechanism can address security of supply objectives in a power market undergoing an energy transition that combines energy efficiency efforts to stabilise demand and a rapid increase in the proportion of renewables to analyse this situation power markets are simulated over the long term with a system dynamics model integrating new investment and closure decisions this last trait is relevant to studying investment in power generation in mature markets undergoing policy shocks the energy only market design with a price cap with and without a capacity mechanism is compared to scarcity pricing in two investment behaviour scenarios with and without risk aversion the results show that the three market designs lead to different levels of risk for peaking unit investment and results thus differ according to which risk aversion hypothesis is adopted assuming a risk neutral investor the results indicate that compared to an energy only market with a price cap at 3 000 mwh an energy only market with scarcity pricing and the market design with a capacity mechanism are two efficient options to reach similar levels of load loss but under the hypothesis of risk aversion the results highlight the advantage of the capacity mechanism over scarcity pricing

optimal policy for an inventory system with backlogging and all units discounts application to the composite lot size model this paper examines an inventory model with full backlogging and all units quantity discounts the practical scenario of a salesperson offering compensation to a client so as not to lose the sale is considered the cost of a backorder thus includes both a fixed cost and a further cost which is proportional to the length of time the said backorder exists a first algorithm is developed to determine the optimal policy while some extensions to this algorithm are obtained that include additional conditions on the model in particular the well known composite lot size model developed by tersine is solved incorporating a new stockout cost and a new all units discount numerical examples are provided to illustrate the application of the algorithms

the impact of renewables on electricity prices in germany an estimation based on historic spot prices in the years 2011 2013 abstract germany s public opinion and media usually attribute increasing electricity prices to the high share of renewables in the german power system but average electricity prices at the european energy exchange dropped during the last years due to an excess of renewable energy this study uses historic market data in order to quantify the effect of renewables on prices historic demand and supply curves from 2011 to 2013 have been used to reconstruct electricity prices under the assumption that no wind and pv would be available the analysis reveals an astonishingly high increase of market prices up to 5 29 ct kwh due to a lack of non renewable power capacities in 2013 the available conventional capacity would not have been able to cover the demand during 269 hours the estimated maximum deficit of 5 6 gw is in good agreement to data published by the german grid operators the discussion of the origin of this deficit leads to the conclusion that the current situation has not been caused by renewables the liberalization of the european energy market established investment risks that hindered required investment a long time before the renewables boomed

optimal replenishment policies for non instantaneous deteriorating items with price and stock sensitive demand under permissible delay in payment abstract this study is motivated by the paper of chang et al international journal of production economics 123 2010 62 68 we extend their inventory model from two aspects 1 the demand rate as multivariate function of price and level of inventory 2 delay in payment is permissible under these assumptions we first formulated a mathematical model and then some useful theoretical results have been derived to characterize the optimal solutions for non zero and zero ending inventory system numerical examples are presented to illustrate the theoretical results the sensitivity analysis of a suitable example is performed and some managerial insights are proposed our analysis revels that it is more beneficial to keep higher inventory level hoping to stimulate more demand even if it results in non zero ending inventory

entry into the electricity market uncertainty competition and mothballing options the present paper analyzes the entry strategies into the electricity market of two firms that have power plants under price uncertainty and competition we consider the symmetric and asymmetric two firms which have either a thermal power plant or a nuclear power plant the differences between the thermal power plant and the nuclear power plant such as the cost structure and operational flexibility are modeled the threshold values of market entry are calculated for each firm with either the thermal power plant or the nuclear power plant as the leader or the follower we show the dependence of cost structures on entry thresholds of the leader and the follower into the electricity market for various market and cost conditions the diagrams of the leader are also shown

reliability payments to generation capacity in electricity markets abstract electric power is a critical input to modern economies generation adequacy and security of supply in power systems running under competition are currently topics of high concern for consumers regulators and governments in a market setting generation investments and adequacy can only be achieved by an appropriate regulatory framework that sets efficient remuneration to power capacity theoretically energy only electricity markets are efficient and no additional mechanism is needed nonetheless the energy only market design suffers from serious drawbacks therefore jointly with the evolution of electricity markets many remunerating mechanisms for generation capacity have been proposed explicit capacity payment was the first remunerating approach implemented and perhaps still the most applied however this price based regulation has been applied no without severe difficulties and criticism in this paper a new reliability payment mechanism is envisioned capacity of each generating unit is paid according to its effective contribution to overall system reliability the proposed scheme has many attractive features and preserves the theoretical efficiency properties of energy only markets fairness incentive compatibility market power mitigation and settlement rules are investigated in this work the article also examines the requirements for system data and models in order to implement the proposed capacity mechanism a numerical example on a real hydrothermal system serves for illustrating the practicability of the proposed approach and the resulting reliability payments to the generation units

effects of a european electricity market on the german electricity industry results from a simulation model of the european power systems the introduction of an european common market for electricity and the opening of the power markets to eastern europe and scandinavia will have a drastic and lasting effect on the structure of the german electricity industry this paper presents an evaluation of the possible effects of a single market especially on the power trade within europe and the german power plant system one special aspect is the investigation whether a flooding of the german electricity market with french nuclear power could happen scenario simulations reject the argumentation that a european common market for electricity would lead to a dramatic increase in international electricity trade

risk based assessment of the cost efficiency and the effectivity of renewable energy support schemes certificate markets versus feed in tariffs the introduction of renewable energy sources in the electricity generation mix has the potential to reduce power sector s emissions and countries dependence on imported oil climate change concerns and highly volatile oil prices have attracted governments interest and support to sustain investments in renewable energy capacity and different support policies have been implemented in many countries around the world this paper analyzes the effects of investors risk aversion on the performance of support schemes the analysis compares two policy options a feed in tariff mechanism with a certificate market system results show that while a tariff mechanism could obtain better results than a certificate market its performance is strictly dependent on regulator choices a certificate market instead permits to obtain the desired level of renewable energy market share with good cost efficiency as long as investors risk aversion is moderate moreover discounting future cash flows with higher social discount rates further benefits a certificate system making it preferable to feed in tariffs

differential difference equations in economics on the numerical solution of vintage capital growth models we examine techniques for the analytical and numerical solution of state dependent differential difference equations such equations occur in the continuous time modelling of vintage capital growth models which form an important class of models in modern economic growth theory the theoretical treatment of non state dependent differential difference equations in economics was discussed by benhabib and rustichini 1991 in general though the state dependence of a model prevents its analytical solution in all but the simplest of cases we review a numerical method for solving state dependent models using simple examples to illustrate our discussion in addition we apply this numerical method to the solow vintage capital growth model

value of disruption information in an eoq environment abstract we consider an infinite horizon continuous review inventory model with deterministic stationary demand where supply is subject to disruption the supply process alternates between two states randomly one in which it functions normally on period and one in which it is disrupted off period in this setting we seek the value of disruption information which enables the buyer to place disruption orders at the beginning of off periods utilizing renewal theory we derive the total expected cost and characterize the optimal regular order up to level together with the order up to level for disruption orders we also conduct an extensive numerical analysis and compare the results with the model with no opportunity of disruption orders we observe that if the shortage cost is relatively high and the disruption risk is significant in terms of duration and or frequency placing a disruption order reduces the expected total cost significantly

long term assessment of power capacity incentives by modeling generation investment dynamics under irreversibility and uncertainty abstract in actual energy only markets the high volatility of power prices affects the expected returns of generators when dealing with irreversibility under uncertainty deferring decisions to commit in new power plants waiting for better information is therefore a rational approach theoretical and empirical evidence suggests that such investment pattern determines the occurrence of construction cycles which strongly compromise supply security in order to supplement generators revenues several remuneration mechanisms have been devised over past years along this line this work addresses the long run dynamics of capacity adequacy and market efficiency with both a price based and a quantity based capacity remuneration policy for that purpose a recently developed stochastic simulation model is used as a benchmark hence the optimal postponement of generation investment decisions is integrated into a long run power market model by formulating the decision making problem in the framework of real options analysis results suggest that policymakers may exchange supply security effectiveness for energy prices to be paid by consumers efficiency when designing and implementing capacity remuneration mechanisms by doing so this article contributes to the ongoing debate regarding the design of incentive policies and efficient power markets by considering the microeconomics of investors decision making under irreversibility and uncertainty