agricultural price instability a survey of competing explanations and remedies there are two explanations for agricultural price dynamics one follows cobweb logic and models fluctuations driven by expectation errors but emphasises that these expectations create complex dynamics and possibly chaos the other stems from the rational expectations tradition of dynamics driven by real shocks the empirical evidence tends to support the latter but is not conclusive the rational expectations model generates an optimal dynamic path from which no improvement can be expected from public intervention however if we take account of all the potential market failures in agricultural markets and especially in developing countries this conclusion might require some qualifications although an appropriate policy design for stability has still to be achieved this paper surveys the positive and normative literature on agricultural prices highlighting empirical evidence and identifying remaining unresolved issues

residential energy demand in oecd countries and the role of irreversible efficiency improvements abstract after undergoing substantial changes during a period of high energy prices household energy demand did not rebound in times of declining energy prices as might have been expected hence other factors such as irreversible improvements in technical efficiency must be understood in order to describe both past and future household energy demand in this paper we consider irreversible efficiency improvements as a major reason for the moderate growth in energy demand after the plummeting of the oil price in 1985 we test different econometric models to take into account efficiency indicators the major conclusions of our investigation are i price elasticities are different for rising and falling prices for the latter they are close to zero implying a low rebound effect in the residential sector ii technical efficiency is an important parameter for describing and forecasting energy demand and iii income elasticities turn out to be higher once we incorporate indicators of technological efficiency in the process of estimating energy demand

wheat storage and trade in an efficient global market domestic and international linkages in speculative stockholdings and trade of wheat are analyzed using a dynamic rational expectations model of the world wheat market dominated by the u s and the eu the results demonstrate the importance of endogenizing both storage and trade in studying commodity markets and suggest that past government stockholdings have not followed efficient market outcomes results indicate that elimination of the export enhancement program by the u s and of export restitution payments by the eu are unlikely to have a major impact on wheat exports from the two regions but will save millions of tax dollars in both regions

estimation of dynamic nonlinear rational expectations models of primary commodity markets with stochastic dynamic programming and disequilibrium maximum likelihood methods are combined to estimate a dynamic nonlinear rational expectations model of a market for a storable primary commodity the estimation model captures the inherently nonlinear structure of private stockholding dynamics the disequilibrium effects of government buffer stock intervention and the impact of price expectations and risk on private supply and stockholding decisions copyright 1993 by mit press

short and long run elasticities in energy demand a cointegration approach abstract short and long run energy demand elasticities are estimated on danish annual data for 1948 1990 energy consumption the real price of energy and real gdp appear to be non stationary variables cointegration and error correction methods are therefore applied all estimated parameters have the expected signs and magnitudes and no evidence is found of a structural break in energy demand caused by the increases in real energy prices since 1973 74

volatility in wheat spot and futures markets 1950 1993 government farm programs seasonality and causality we explore how wheat spot and futures market volatility has been impacted by government farm programs during the 1950 1993 period we find that changing volatility in both markets is highly associated with changing farm programs the mandatory allotment programs of the 1950s and early 1960s 1 3 50 4 10 64 were associated with low volatility while the voluntary programs initiated in the mid 1960s seem to have induced high volatility 4 11 64 12 22 85 both market driven loan rates and conservation reserve programs appear to have helped volatility revert to lower levels since the mid 1980s 12 23 85 12 30 93 we also examine seasonality and causality in conjunction with the farm programs we explore how wheat spot and futures price volatility has been impacted by government farm programs many studies have examined the effects of various farm policies mckinnon 1967 blakeslee 1980 miranda and helmberger

final offer arbitration in final offer arbitration the two parties to a dispute submit final offers to an arbitrator the arbitrator then chooses as the binding solution that offer which is closest to his own view of the appropriate outcome because the disputants are imperfectly informed about the arbitrator s preferences final offer arbitration can be modeled as a game of imperfect information interesting questions arise concerning the nature of the optimal strategies and how they are affected by different characteristics of the arbitrator and the disputants we provide conditions for an equilibrium to exist in a final offer arbitration game when there are k issues the probability function is not specified and the disputants are either risk averse or risk neutral furthermore the players may have differing beliefs about the arbitrator s probability function we demonstrate that increased risk aversion by one of the parties will result in both players choosing positions farther away from the more risk averse party we also discover the affect of bias as well as the effect of increased sensitivity by the arbitrator on the positions taken by the players

towards sustainability of energy systems a primer on how to apply the concept of energy services to identify necessary trends and policies virtually all goods and services that characterize modern societies welfare depend on the provision of commercial energy the core objective of this paper is to identify necessary changes in trends for achieving a transition towards more sustainable energy systems and development paths the major conclusions of this analysis are i a rigorous rethinking process has to take place to identify which level of energy services per capita lead to enhancing human welfare and quality of life ii a significant increase in energy conversion efficiency has to be triggered to finally provide energy services with far less input of energy than today iii a continuous increase in the share of renewable energy sources and other low emission options has to be brought about iv however as history has shown this process of technological learning has to be accompanied by proper energy price and regulatory policies otherwise it is very likely that energy conservation gains due to technical efficiency improvements will be outweighed again by increases in energy service demand and straightforward energy consumption and co 2 emissions

consequences of discretion in the formation of commodities policy abstract in a simple model of endogenous primary commodity price support policy i policy is affected by private inventories and ii private inventories are affected by speculative attempts to forecast policy the interaction between these two forces is rich yielding bubbles and extrinsic volatility thus helping to explain some odd episodes observed in commodity markets in addition under some conditions a government that wishes to support the price but is unable to commit to future action may be impotent and a government that does not want to support the price may be trapped into doing so by speculative activity

the effects of commodity price stabilization programs in this paper the authors analyze the effects of commodity programs in which the government attempts to support and stabilize price through open market purchases and sales specifically they as sess the effects of such programs on the u s soybean market using a rational expectations model that allows for private storage expected price responsive production and arbitrary support and release price s a salient feature of the model is that private storage and product ion behavior adjusts to changes in government policy stochastic simu lations of the market model demonstrate that price stabilization prog rams can reduce long run market price and destabilize producer revenu e copyright 1988 by american economic association

comparing solution methods for dynamic equilibrium economies this paper compares solution methods for dynamic equilibrium economies the authors compute and simulate the stochastic neoclassical growth model with leisure choice using undetermined coefficients in levels and in logs finite elements chebyshev polynomials second and fifth order perturbations and value function iteration for several calibrations the authors document the performance of the methods in terms of computing time implementation complexity and accuracy and they present some conclusions about their preferred approaches based on the reported evidence

final offer arbitration and risk aversion in bargaining negotiations are often conducted under the stipulation that an impasse is to be resolved using final offer arbitration foa in fact foa frequently is not needed in major league baseball for instance more than 80 of the salary negotiations that could go to arbitration instead reach a bargained agreement we show that the risk aversion of at least one side explains this phenomenon we then model pay negotiation in baseball by applying a bargaining solution with a variable disagreement outcome representing foa studying the existence of pure nash equilibrium initial offers and their effects on the player s eventual pay and considering the nash solution as a special case

perfect equilibria in a model of bargaining with arbitration abstract we consider an alternating offer bargaining model in which the players may agree to call in an arbitrator in case of disagreement the main message of our study is that the mere presence of an arbitrator who can only become active with the consent of both parties in the background of negotiations may entirely drive their outcome we compare our results with those obtained in models with outside options journal of economic literature classification number c78

managing food price risks and instability in a liberalizing market environment overview and policy options abstract managing food price risks and instability is a major challenge in the midst of ongoing food market reforms key findings from the papers in this special volume revolve around five broad areas i the sources and magnitudes of food price instability in different country contexts ii the economic and social costs stemming from price instability iii the lessons from food market reforms to date iv the design of policy reforms in ways that promote efficient and stable market development and protect the interests of the poor and v potential policy responses to food price instability in a liberalizing market environment

price stabilization using buffer stocks abstract the price stabilization problem is stated and solved for a nonlinear cobweb model with government stocks it is shown that if the storage capacity for the commodity is sufficiently large then there exists a simple stabilization policy called the keep supply at equilibrium kse policy such that the equilibrium price is a global attractor for the corresponding closed loop system in addition it is shown that if the government approximates the equilibrium supply with the average supply stabilization is guaranteed we refer to this policy as keep supply at average ksa

how much of commodity price behavior can a rational expectations storage model explain a rational expectations competitive storage model was applied to the u s corn market to assess the aptness of this framework in explaining monthly price behavior in an actual commodity market relative to previous models extensive realism was added to the model in terms of how production activities and storage costs are specified by modeling convenience yield backwardation in prices between crop years did not depend on the unrealistic assumption of zero ending stocks our model generated cash prices that were distributed with positive skewness and kurtosis and mean and variance that increased over the storage season comparable to the persistence and the occasional spikes observed in commodity prices futures prices were generated as conditional expectations of cash prices at contract maturity and the variances of futures prices exhibited realistic time to maturity and seasonal patterns model realizations of cash and futures prices over many years were used to demonstrate the wide variety of price behaviors that could be observed in an efficient market with a similar market structure implying that economic and policy implications drawn from short historical samples of prices could be misleading

can private motor vehicle augmenting technical progress reduce household and total fuel use abstract this paper demonstrates the importance of modelling energy intensive household services in general and private transportation in particular as combinations of energy and other inputs initially a partial equilibrium approach is used to analyse private transport consumption as a self produced commodity formed by household vehicle and fuel use we particularly focus on the impact of private vehicle augmenting technical progress in this framework we show that household fuel use will fall if it is easier to substitute between vehicles and fuel in the household production of private transport services than it is to substitute between private transport and the composite of all other goods in overall household consumption the analysis is then extended through computable general equilibrium simulation to investigate the wider implications of similar efficiency improvements when intermediate demand prices and nominal income are endogenous the subsequent reduction in the price of private transport service not observable in market prices allows the wage measured relative to the cpi to rise whilst the wage relative to the price of foreign goods falls this simultaneously increases uk international competitiveness encouraging increased exports and reduced import penetration whilst allowing employment to rise this provides an additional supply side stimulus to production employment and household income

modelling residential electricity demand in the gcc countries abstract this paper aims at understanding the drivers of residential electricity demand in the gulf cooperation council countries by applying the structural time series model in addition to the economic variables of gdp and real electricity prices the model accounts for population weather and a stochastic underlying energy demand trend as a proxy for efficiency and human behaviour the resulting income and price elasticities are informative for policy makers given the paucity of previous estimates for a region with particular political structures and economies subject to large shocks in particular the estimates allow for a sound assessment of the impact of energy related policies suggesting that if policy makers in the region wish to curtail future residential electricity consumption they would need to improve the efficiency of appliances and increase energy using awareness of consumers possibly by education and marketing campaigns moreover even if prices were raised the impact on curbing residential electricity growth in the region is likely to be very small given the low estimated price elasticities unless that is prices were raised so high that expenditure on electricity becomes such a large proportion of income that the price elasticities increase in absolute terms

modelling market fundamentals a model of the aluminium market the standard approach to modelling primary commodity markets under rational expectations is to relate the commodity price to the production and consumption surprises i e the innovations on the equations using the world aluminium market we show how this approach can be modified so that both the price and stock can be written in terms of one or more market fundamentals which reflect the supply demand balance on the market this approach allows joint estimation of production consumption stock demand and price equations subject to cross equation restrictions it may be seen as a formalization of the approach adopted by metals industry analysts

asymmetric price responses and the underlying energy demand trend are they substitutes or complements evidence from modelling oecd aggregate energy demand abstract a number of energy demand studies have considered the importance of modelling asymmetric price responses apr for example the often cited work of gately and huntington 2002 griffin and schulman 2005 questioned the asymmetric approach arguing that this is only capturing energy saving technical progress huntington 2006 however showed that for whole economy aggregate energy and oil demand there is a role statistically for both apr and exogenous energy saving technical change in a separate strand of the literature the idea of the underlying energy demand trend uedt has been developed see for example hunt et al 2003a and 2003b and dimitropoulos et al 2005 they argue that it is important in time series energy demand models to allow for stochastic trends or uedts based upon the structural time series dynamic regression methodology recommended by harvey 1989 1997 this paper attempts to bring these strands of the literature together by proposing a testing procedure for the uedt and apr in energy demand models within both a panel context consistent with the huntington 2006 approach and the structural time series modelling framework a set of tests across a range of specifications using time series and panel data are therefore suggested in order to try and ascertain whether energy saving technical change or the more general uedt and apr are substitutes for each other when modelling energy demand or whether they are actually picking up different influences and are therefore complements using annual whole economy data for 17 oecd countries over the period 1960 2006 the results suggest that for most of the countries the uedt is preferred to apr whereas for another group the uedt and apr are complements and for another group they are substitutes it is argued therefore that energy demand modellers should not assume at the outset that one method is superior to the other moreover wherever possible a general model be it in a time series or panel context that includes a non linear uedt and apr should be initially estimated and only if accepted by the data should symmetry and or a more restrictive uedt be imposed

the rebound effect microeconomic definitions limitations and extensions abstract the rebound effect results in part from an increased consumption of energy services following an improvement in the technical efficiency of delivering those services this increased consumption offsets the energy savings that may otherwise be achieved if the rebound effect is sufficiently large it may undermine the rationale for policy measures to encourage energy efficiency the nature and magnitude of the rebound effect is the focus of long running dispute with energy economics this paper brings together previous theoretical work to provide a rigorous definition of the rebound effect to clarify key conceptual issues and to highlight the potential consequences of various assumptions for empirical estimates of the effect the focus is on the direct rebound effect for a single energy service indirect and economy wide rebound effects are not discussed beginning with khazzoom s original definition of the rebound effect we expose the limitations of three simplifying assumptions on which this definition is based first we argue that capital costs form an important part of the total cost of providing energy services and that empirical studies that estimate rebound effects from variations in energy prices are prone to bias second we argue that energy efficiency should be treated as an endogenous variable and that empirical estimates of the rebound effect may need to apply a simultaneous equation model to capture the joint determination of key variables third we explore the implications of the opportunity costs of time in the production of energy services and highlight the consequences for energy use of improved time efficiency the influence of time costs on the rebound effect and the existence of a parallel rebound effect with respect to time each of these considerations serves to highlight the difficulties in obtaining reliable estimates of the rebound effect and the different factors that need to be controlled for we discuss the implications of these findings for econometric studies and argue that several existing studies may overestimate the magnitude of the effect

worldwide acreage and yield response to international price change and volatility a dynamic panel data analysis for wheat rice corn and soybeans this study estimates a worldwide aggregate supply response for key agricultural commodities namely wheat rice corn and soybeans by employing a newly developed multi country crop and calendar specific seasonally disaggregated model with price changes and price volatility applied accordingly the findings reveal that although higher output prices serve as incentives to improve global crop supply as expected output price volatility acts as a disincentive depending on the crop the results show that own price supply elasticities range from about 0 05 to 0 40 output price volatility however has negative correlations with crop supply implying that farmers shift land other inputs and yield improving investments to crops with less volatile prices simulating the impact of price dynamics since 2006 we find that price risk has reduced the production response of wheat in particular and to a lesser extent rice thus dampening price incentive effects the simulation analysis shows that the increase in own crop price volatility during the 2006 2010 period has dampened yield by about 1 2 for the crops considered

on the interpretation of the nash bargaining solution and its extension to non expected utility preferences the paper reexamines the foundations of the axiomatic nash bargaining theory more specifically it questions the interpretation of the nash bargaining solution and extends it to a family of non expected utility preferences a bargaining problem is presented as x d 2 where x is a set of feasible agreements described in physical terms d is the disagreement event and 1 and 2 are preferences defined on the space of lotteries in which the prizes are the elements in x and d the ordinal nash bargaining solution is defined as an agreement y satisfying for all p e 0 1 and for all x e x if px 1 y then py 2 x and if px 2 y then py x where px is the lottery which gives x with probability p and d with probability 1 p revisions of the pareto symmetry and iia axioms characterize the ordinal nash bargaining solution in the expected utility case this definition is equivalent to that of the nash bargaining solution however this definition is to be preferred since it allows a statement of the nash bargaining solution in everyday language and makes possible its natural extension to a wider set of preferences it also reveals the logic behind some of the more interesting results of the nash bargaining solution such as the comparative statics of risk aversion and the connection between the nash bargaining solution and strategic models

energy consumption and economic activity in industrialized economies a note abstract in industrialized countries the income elasticity of primary energy demand is not far off unity furthermore it can be argued that there is little use in distinguishing between short and long term income elasticities a long term income elasticity does not have a direct impact on energy demand and hence it is of doubtful use in energy demand projections via an aggregate oecd model it was estimated that the short term impact of prices on primary energy demand is about 0 15 while the long term impact is 0 43 but increasing over time

the production of housing services and the derived demand for residential energy most studies of residential energy usage treat energy as a final consumer good this study explicitly considers the production of housing service flows from stocks of real estate and flows of operating inputs and considers the demand for residential energy as a factor input the empirical results based upon analysis of a sample of newly constructed dwellings and their occupants are used to evaluate the effects of energy price changes on the price of housing services and on the demand for housing and real estate thus indicating the extent of residential energy conservation in response to higher prices finally the results are used to analyze federal and state tax subsidies for residential energy conservation

measuring the effects of price controls using mixed complementarity models abstract government involvement in managing domestic prices of energy and other commodities is a major issue in emerging economies we examine one aspect of the problem price controls when governments set or cap prices we show how a mixed complementarity problem mcp formulation can be used to model and assess the impacts of price controls in multi sector economic equilibrium models both the gains from deregulation and the consequences of imposing new or altering existing regulations can thus be measured we present three distinct models that capture different price control situations firms have to meet demand and receive an implicit subsidy demand rationing occurs due to an associated price control constraint and subsidies limit demand rationing we present an approach to measuring the effects on the equilibrium in the first case and the levels of disequilibrium induced by price controls in the other cases we also show how to determine the most efficient allocation program when a government engages in rationing we illustrate the cases described by these models using markets that have or had price controls

optimal food price stabilization in a small open developing country in poor countries most governments implement policies aiming to stabilize the prices of staple foods which often include storage and trade measures insulating their domestic market from the world market it is of crucial importance to understand the precise motivations and efficiency of those interventions because they can have consequences worldwide this paper addresses those issues by analyzing the case of a small open developing country confronted by shocks to both the crop yield and foreign price in this model government interventions may be justified by the lack of an insurance market for food prices considering this market imperfection the authors design optimal public interventions through trade and storage policies they show that an optimal trade policy largely consists of subsidizing imports and taxing exports which benefits consumers at the expense of producers import subsidies alleviate the non negativity of food storage in other words when stocks are exhausted subsidizing imports prevents domestic price spikes one striking result an optimal storage policy on its own is detrimental to consumers since its stabilizing benefits leak into the world market and it raises the average domestic price by contrast an optimal combination of storage and trade policies results in a powerful stabilizing effect for domestic food prices

hedging grain price risk in the sadc case studies of malawi and zambia abstract we use simulation methods to examine the results of hedging maize food security imports into malawi and zambia on the south african exchange safex results show that hedging using either futures or options can spread import costs over time thereby reducing variability and also possibly generating lower average costs these benefits are increased if hedging only takes place when local prices are at less than import parity and also if the hedge is levered however problems will remain so long as intra regional transport costs remain high

nash solution and uncertain disagreement points abstract we analyze bargaining problems with known feasible sets but uncertain disagreement points we investigate the existence of solutions such that under reasonably restricted circumstances all agents be as well off by reaching an agreement today as they would be by waiting until the uncertainty is resolved we use this requirement together with a few other commonly used conditions to characterize the nash solution

interdependencies between transport fuel demand efficiency and quality an application to austria abstract this paper focuses on the interdependencies between technical efficiencies and energy demand which are often either treated in isolation or do not get the sufficient attention in the literature more precisely this paper uses technical efficiencies as one crucial determinant of energy demand in order to integrate at least two issues that are usually investigated separately from each other the rebound effect resulting from improved technical efficiencies and the asymmetry of energy demand in this regard our paper sets out a theoretical framework which has the following implications higher efficiency increases service demand first order rebound low fuel prices and higher efficiency increases the demand for quality second order which in turn increases service demand further third order ceteris paribus energy price shocks should increase scrapping rates fuel prices direct the rd those on engine efficiency are irreversible which has the consequence that energy price elasticities depend on the history of energy prices rather than being asymmetrical derived implications are subsequently tested on austrian data in particular the purchasing decision diesel versus gasoline powered cars allows to refute the myth that consumers apply high implicit rates for discounting the future benefit from efficient cars

the use of organized commodity markets to manage food import price instability and risk the article explores the possibility of insuring the price risks of wheat and maize imports of low income food deficit countries lifdcs optimal strategies for an importing agent who hedges with futures and options are derived based on the objective of minimizing the unpredictability of import bills ex post simulations for a set of lifdcs are run on wheat and maize imports hedged with futures and options in the chicago board of trade to explore the extent to which hedging reduces the unpredictability in import bills simulations encompass both periods of normal price behavior as well as the period of global upheaval that occurred in 2007 and 2008 results show that hedging with futures alone affords agents considerable opportunities for reducing import cost unpredictability and the same holds with options albeit to a lesser extent however during the recent price spike of 2007 2008 hedging with options would have increased the unpredictability of some countries maize import bills due to the combination of erratic import patterns and pronounced market uncertainty

pricing and storage of field crops a quarterly model applied to soybeans this paper considers the role of competitive storage in markets for annually harvested field crops a quarterly model is presented that considers the allocative role of storage both within and between crop years rational price expectations are endogenous variables calculated by a recursive method forward stochastic simulations using the model generate data that can be used to characterize the distributions of the variables in the base case the model is assigned parameter values from a quarterly econometric model of the u s soybean market the results shed light on the distributions of the quarterly variables including the rational price expectations and show how these distributions are affected by changes in the carrying charge

price effects of energy efficient technologies a study of residential demand for heating and cooling energy efficient appliances reduce the marginal price of the services they deliver this article shows empirically that such price reductions result in energy savings that are smaller than those engineering techniques generally project using econometric techniques with data from a unique utility experiment and a detailed engineering thermal load model we find that actual conservation is as much as 13 below engineering estimates for cooling and 8 12 below for heating customers who conserve electricity are also persistent their houses are comparatively warmer in summer and cooler in winter

short and long run adjustments in u s petroleum consumption long run adjustments in petroleum consumption are not only larger than short run adjustments they may also be motivated by entirely different price events this analysis shows that new price peaks have both short run and long run consumption responses a result that is starkly different than price changes that track previous price paths it also establishes significant trend effects where gasoline and residual fuel oil consumption decline over time the analysis explores these adjustments by establishing long run cointegrating relationships for different petroleum product groupings an important implication is that price increases above historical levels may be providing substantially greater incentives for significant long run demand adjustments than would be the case otherwise

four approaches to commodity market stabilization a comparative analysis the effects of four alternative price stabilization programs for soybeans are compared using a rational expectations model and simulation for a given government expenditure subsidized private storage is the most efficient way to stabilize market price for a given deadweight loss a program of direct payments is the most efficient stabilizer of the effective farm price this program does not stabilize market price all four programs including a buffer stock program and one involving both direct payments and buffer stocks tend to destabilize quasi rent programs that involve an initial build up of stocks increase producer benefits and hurt consumers

the economic role of commodity storage one of the earliest and most successful exainples of economic policy is the oftquoted biblical account of joseph s interpretation of the pharoah s dream joseph foretold that seven years of abundant harvests would precede seven years of drought and recommended that the pharoah accumulate grain during the good years since that time the central role of storage in stabilising the economy in the face of exogenous disturbances has been obvious but our understanding of the nature of that role has not greatly advanced without divine assistance in forecasting stochastic production the storage decision is considerably more complex than the one joseph faced and the role of storage quite different in fact several commonly held impressions about the role of storage of commodities such as grains are incorrect rather than stabilising production storage actually accentuates its variability rather than causing a mean price preserving decrease or a mean output preserving decrease in the dispersion of price storage generally causes a more complex modification of the distribution of price rather than being most effective at eliminating short falls in consumption storage actually is more effective at eliminating the incidence of exceedingly high consumption in this paper we explore the role of storage in a model where production is stochastic and both production and storage are performed by competitive profitmaximisers who form rational expectations about the returns to their activities we derive the subtle but very important interactions among production price expectations and storage which simpler models cannot capture finally we make a comparative statics assessment of the distributional implications of storage these results while confirming the importance of the specification of the demand function and the supply elasticity identified in recent analytical studies e g wright i979 and newbery and stiglitz i979 are surprisingly favourable to consumers considering the asymmetric nature of the effects of storage on consumption and price storage is simply a productive activity one that transfers a commodity from one period to the next like other forms of production it is costly the total cost of storing an amount st from period t to period t i is as of period t i

underlying trends and seasonality in uk energy demand a sectoral analysis this paper demonstrates the importance for energy demand modelling of allowing for trends and seasonal effects that are stochastic in form inherent underlying trends may be non linear and reflect not only technical progress which usually produces greater energy efficiency but also other factors such as changes in consumer tastes and the economic structure that may be working in the opposite direction using quarterly unadjusted data for various sectors in the uk it is shown that unless energy demand models are formulated so as to allow for stochastic trends and seasonals estimates of price and income elasticities could be seriously biased

the vulnerability of price stabilization schemes to speculative attack this paper examines the effects of government attempts to stabilize the prices of commodities by use of buffer stocks agricultural goods subject to supply uncertainty as well as depletable resources are considered in each case it is shown that the resulting rational expectations competitive equilibrium contains a speculative attack a situation where the entire government stock is suddenly purchased by previously inactive speculators the analysis is applied to the historical attempt to peg the gold price which caused the attack of 1968 the insights gained and the methodology developed also apply to the various international agreements to impose bans on commodity prices which have been proposed by the united nations conference on trade and development

food price seasonality in africa measurement and extent everyone knows about seasonality but what exactly do we know this study systematically measures seasonal price gaps at 193 markets for 13 food commodities in seven african countries it shows that the commonly used dummy variable or moving average deviation methods to estimate the seasonal gap can yield substantial upward bias this can be partially circumvented using trigonometric and sawtooth models which are more parsimonious among staple crops seasonality is highest for maize 33 percent on average and lowest for rice 16 percent this is two and a half to three times larger than in the international reference markets seasonality varies substantially across market places but maize is the only crop in which there are important systematic country effects malawi where maize is the main staple emerges as exhibiting the most acute seasonal differences reaching the sustainable development goal of zero hunger requires renewed policy attention to seasonality in food prices and consumption

government target price intervention in economies with incomplete markets the target price deficiency payment program is among economists favorite examples of costly government intervention in competitive markets dubbed the brannan plan after president truman s secretary of agriculture this program pays producers any positive difference between a given target price and the prevailing market price for their output in a world of certainty and perfect competition such an intervention benefits producers hurts consumers as taxpayers and causes a net harberger triangle welfare loss these implications are not only standard fare in economics lecture halls they have become conventional wisdom in contemporary policy discussions for example the 1986 economic report of the president states income support programs by inhibiting the efficient operation of agricultural markets can impose extra costs on consumers and taxpayers that exceed the amount of income transferred to farmers when such losses occur the programs are doing more than redistributing income they are wasting valuable economic resources that could be used to make everyone better off the object of this paper is to show that these conclusions do not extend to a stochastic production economy with incomplete contingent claim markets in the latter setting the distributional and welfare implications of a brannan plan can be reversed producers can be made worse off consumers can be made better off and with nonstochastic compensation all agents can be made better off the conditions under which these outcomes occur include producer risk aversion and low price and income elasticities of demand all well known characteristics of staple food markets in which target price programs are actually employed e g markets for wheat corn and rice like many other equilibrium analyses of resource allocation

policy implications of considering pre commitments in u s aggregate energy demand system abstract linear approximations of the generalized almost ideal demand system and almost ideal demand system for u s energy are compared to contrast the explicit inclusion and exclusion of pre committed consumption levels results indicate that pre commitment levels the quantity of a good that is consumed in the short run with little regard for price helps to better explain energy demand in the u s compared to the system that does not explicitly consider pre commitments policy implications are if pre commitments are a legitimate assumption larger price changes are necessary to achieve a given policy objective than if there are no pre commitments

false promise or false premise the experience of food and input market reform in eastern and southern africa abstract the literature on the effects of agricultural market reform in africa is sharply divided and inconsistent this article attempts to reconcile opposing viewpoints on the effects of food and input market policy reform in eastern and southern africa drawing from studies of ethiopia kenya malawi zambia and zimbabwe we argue that a major source of the controversy stems from assumptions that countries have actually moved to a liberalized market environment we find that many of the most fundamental elements of the reform programs either remain unimplemented were reversed within several years or were implemented in such a way as to negate private sector investment incentives a framework is developed for explaining why some countries have been able to liberalize their food and fertilizer markets while others have not these findings have implications for how donor assistance and policy oriented research can more constructively contribute to an improved policy environment

how sensitive to time period sampling is the asymmetric price response specification in energy demand modelling abstract the purpose of this paper is to investigate the criticism that energy demand estimates based on a specific price decomposition are sensitive to the chosen time period used for the estimation to analyse this in a systematic way different time series sample periods are constructed from annual data for 17 oecd countries covering the overall period 1960 to 2008 the specific price decomposition under consideration often used to estimate asymmetric price response models of energy demand separates the impact of prices above the previous maximum of a price recovery below the previous maximum and of a price cut therefore the analysis does not just involve using different time periods instead for each time period investigated a new dataset is constructed and for each dataset the price variable is decomposed in this way an energy demand relationship allowing for asymmetric price responses is therefore estimated for each different sample period and the results suggest that recalculation of the decomposed price variables for each different period does affect the stability of the estimated energy demand responses in contrast a similarly estimated energy demand relationship with symmetric price responses for each different sample period is found to have less instability

the theory of food price stabilisation a small and very volatile fraction of total domestic food production many countries aim at food self sufficiency with the consequence that the country may be an exporter in good years but an importer in bad years international and domestic transport and handling costs are a significant fraction of the average price of cereals so the domestic price fluctuations will tend to be an amplified version of international price fluctuations the difference between the domestic price in exporting and importing years will be twice the transport costs if the world price is unchanged it would require a strong negative correlation between domestic and world supply to offset this additional source of instability 1

processing industry capacity and the welfare effects of sugar policies normally analysis of policies affecting commodities such as sugar employs long run comparative statics under certainty and ignores processing industries like cane sugar refining under the implicit assumption that the capital is malleable in both the short and long run we present a dynamic model calibrated to world sugar and solved with numerical dynamic programming that includes the specific capital of the refining industry when compared to an otherwise identical static model the dynamic model suggests that some 20 of welfare losses may be misattributed to cane sugar producers instead of refiners in contrast the difference between certainty and uncertainty proves to be unimportant

testing rational expectations in primary commodity markets the standard method used to test the rational expectations hypothesis reh in primary commodity markets is by means of a structural approach in this paper a parsimonious vector error correction model in the price and stock equation is derived that maintains almost complete information of the underlying structural model the empirical section utilizes 1955 2000 us copper data to investigate the properties of the model extended to the macroeconomic variables the estimation results are statistically robust and are in keeping with economic theory three different results are found i price adjustments depend on the short run dynamic of the stock equation whereas the long run dynamic is statistically rejected ii the over identification restrictions including the test for the reh are not rejected iii the forecast simulations on price are well performed

demand elasticities in oecd dynamical aspects abstract four models with different lag structures are used to express final energy demand in oecd from 1960 1982 as a function of real gdp and average energy price the income and long run price elasticities are not significantly dependent on the model specification but the koyck lag scheme estimated in its distributed lag form is found to give the most satisfactory results the statistical properties of the data together with evidence of trends in the elasticities both suggest that the period of falling real prices prior to 1971 is not comparable to the present period for the period after 1971 an income elsticity of 1 02 and a long run price elasticity of 0 37 are obtained

rules versus discretion in food storage policies this article compares various policies in a rational expectations food storage model with risk averse consumers and missing insurance markets calibrated to represent a developing country i consider an optimal storage policy under discretion and two optimal simple rules a constant private storage subsidy and a price band the storage subsidy achieves welfare gains similar to the discretionary policy the price band maximizing social welfare is a price peg scheme the floor and ceiling prices are the same and the capacity constraint represents 11 of the steady state production level this price band achieves three quarters of the gains from the optimal policy under discretion

energy consumption and economic activity in industrialized countries the dynamic aggregate time series relationship abstract most econometric studies suggest that the income elasticity of demand for energy is approximately unity for the developed market economies it is shown that over the period 1950 1978 the long run income elasticity is substantially higher than unity in terms of a ces energy demand function this result reflects the application of a generalized dynamic estimation methodology where serial correlation is regarded as a diagnostic guide to distributed lag fitting price elasticities are also estimated but these are in line with conventional estimates

alternative approaches to cost containment in a cap and trade system we compare several emissions reduction instruments including quantity policies with banking and borrowing price policies and hybrid policies safety valve and price collar using a dynamic model with stochastic baseline emissions the instruments are compared under the design goal of obtaining the same expected cumulative emissions across all options based on simulation analysis with the model parameterized to values relevant to proposed us climate mitigation policies we find that restrictions on banking and borrowing including the provision of interest rates on the borrowings can severely limit the value of the policy depending on the regulator chosen allowance issuance path although emissions taxes generally provide the lowest expected abatement costs a cap and trade system combined with either a safety valve or a price collar can be designed to provide expected abatement costs near those of a tax but with lower emissions variance than a tax consistently a price collar is more cost effective than a safety valve for a given expected cumulative emissions outcome because it encourages inexpensive abatement when abatement costs decline

evaluating the effectiveness of inter regional trade and storage in malawi s private sector maize markets abstract this paper evaluates the effectiveness of the private sector maize marketing system in malawi using threshold autoregression models two dimensions of maize market performance are evaluated 1 inter regional trade and spatial price transmission and 2 storage and seasonal price relationships in both cases threshold autoregression models which account for nonlinearities predicted by economic theory are applied results indicate that spatial price transmission and seasonal price patterns in private sector maize markets in malawi are generally consistent with long run competitive inter regional trade and storage behavior and that in most cases shocks to long run equilibrium are arbitraged away quickly this suggests the private sector in malawi is generally doing a good job of transporting maize from surplus to deficit regions and smoothing maize consumption between harvests

economic modelling of energy services rectifying misspecified energy demand functions abstract although it is well known that energy demand is derived since energy is required not for its own sake but for the energy services it produces such as heating lighting and motive power energy demand models both theoretical and empirical often fail to take account of this feature in this paper we highlight the misspecification that results from ignoring this aspect and its empirical implications biased estimates of price elasticities and other measures and provide a relatively simple and empirically practicable way to rectify it which has a strong theoretical grounding to do so we develop an explicit model of consumer behaviour in which utility derives from consumption of energy services rather than from the energy sources that are used to produce them as we discuss this approach opens up the possibility of examining many aspects of energy demand in a theoretically sound way that have not previously been considered on a widespread basis although some existing empirical work could be interpreted as being consistent with this type of specification while this formulation yields demand equations for energy services rather than for energy or particular energy sources these are shown to be readily converted without added complexity into the standard type of energy demand equation s that is are typically estimated the additional terms that the resulting energy demand equations include compared to those that are typically estimated highlight the misspecification that is implicit when typical energy demand equations are estimated a simple solution for dealing with an apparent drawback of this formulation for empirical purposes namely that information is required on typically unobserved energy efficiency indicates how energy efficiency can be captured in the model such as by including exogenous trends and or including its possible dependence on past energy prices the approach is illustrated using an empirical example that involves estimation of an aggregate energy demand function for the uk with data over the period 1960 2011

evaluating the linearized almost ideal demand system linearizing the almost ideal demand system laids by recourse to the stone share weighted price index is common practice two issues are addressed here first scrutiny of the errors in variables implications of the linearization reveals that not only is the sur estimator inconsistent but a consistent iv estimator cannot be constructed second some alternatives to the green alston elasticities specifically designed for the laids model are developed but neither these nor the green alston elasticities are found to have any advantages over the conventional elasticity formulae some errors in the green alston 1990 paper are corrected the inconsistency and elasticity issues are documented by a monte carlo investigation

compulsory arbitration arbitral risk and negotiated settlements a case study in bargaining under imperfect information the effect of conventional and final offer compulsory arbitration on negotiated settlements is characterized using nash s variable threats bargaining solution with particular attention to the interaction between arbitral risk and bargainers risk preferences when there is no arbitral risk both schemes are shown to have the same effect on negotiated settlements under very general conditions even when bargaining is over several issues whether or not there is arbitral risk negotiated settlements favour a bargainer more if his opponent is more risk averse on the other hand increases in arbitral risk need not improve the position of the less risk averse bargainer as a by product of the analysis kihlstrom roth and schmeidler s risk sensitivity results for the nash and raiffa kalai smorodinsky solutions are generalized from fixed threats to variable threats bargaining