money deficit and public debt in the united states this study estimates the underlying parameters in a dynamic game between the fiscal and monetary authorities over the determination of public debt these estimates reveal the policymakers attitude towards the goal of stabilizing the time path of public debt the central finding is that in the united states during the 1955 85 period this goal has been pursued by the fiscal authority but not by the central bank monetary policy has not monetized the stock of public debt outstanding whereas cyclically adjusted net of interest fiscal deficits have been reduced to offset increases in the stock of debt in circulation copyright 1989 by mit press

imports and the supply of winter tomatoes an application of rational expectations a model of the florida tomato industry is formulated under the hypothesis that growers make production decisions as rational economic agents this assumption implies that anticipated mexican tomato imports as well as other economic variables are taken into account when the planting decision is made maximum likelihood estimation methods are used to solve the simultaneous equations model and the implications of the model s reduced form are analyzed the empirical findings are consistent with the rational expectations hypothesis that producers respond to market information in its entirety when making acreage decisions key vwords expectations imports mexico rational expectations supply response tomatoes florida produces about 90 of u s tomatoes harvested for fresh use during the november to mid june season since the cuban trade embargo of february 1962 mexico has become the major foreign supplier of fresh winter tomatoes the total fresh winter tomato market in the united states has been almost equally shared by florida and mexico in recent years the rivalry for this market reached the point in 1978 that florida growers charged that mexican producers were dumping their product on the u s market schmitz firch hillman many florida growers suggest that unless mexican tomato imports are limited the florida tomato industry will effectively disappear primary attention in this paper is focused on domestic tomato acreage allocations in light of the mexican influence on the winter tomato market the paper does not attempt to evaluate the welfare effects of mexican imports on the florida tomato industry in addition to the emphasis on acreage response the domestic quantity and price effects are also considered most efforts to explain acreage devoted to agricultural crops have utilized some variant of a cobweb model because the ultimate price of the crop cannot be ascertained until the completion of the production cycle nevertheless if the supply and demand framework is truly representative of the way the market works an alternative to lagged price for representing the anticipated price for the crop is the price prediction of the supply and demand model itself thus acreage would be dependent on the expected price of the crop and expected price would result from the solution of the supply and demand model for price on the basis of information available at planting time the underlying hypothesis is that producers are acting in accordance with the information available to them at planting time and in a way represented by the interaction in the supply and demand model viewed in this way planted acreage decisions would be based on such factors as anticipated mexican imports and their attendant effect on the price of tomatoes one distinction between this and the traditional cobweb framework is that in the latter case lagged imports may influence planted acreage via their effect on lagged prices but any impact expected imports might have on current price is ignored in the acreage

imperfect price deflation in production systems numeraire prices that are measured with error create challenges for econometric estimation a straightforward approach for a model with linear input demands such as generated from a quadratic normalized profit function is proposed where the numeraire price is measured with error numeraire measurement error is likely because expected output price is measured imperfectly by actual output price an approach using generalized method of moments is developed to estimate such errors in variables systems that avoids use of extra sample data or additional structural specifications monte carlo examination of small sample properties shows promise measurement error is statistically significant using aggregate u s agricultural data

environmental regulation by private contest abstract it is widely expected that the recent trend in the us eu and elsewhere towards an increased role for private agents and agencies in the formulation and enforcement of environmental regulation will continue if environmental regulation is to be privatised in this way it is natural to ask how far the activities of environmental groups on whose shoulders much of the responsibility for defending the environment is likely to fall should be subsidised or taxed in this paper we identify the trade offs involved and characterise the optimal subsidy tax the analysis is argued to have significant implications for how governments should think about the way in which fiscal law treats environmental ngo s

the optimal initial allocation of pollution permits a relative performance approach the initial allocation of pollution permits is an important aspect of emissions trading schemes we generalize the analysis of bohringer and lange 2005 eur econ rev 49 8 2041 2055 to initial allocation mechanisms that are based on inter firm relative performance comparisons including grandfathering and auctions as well as novel mechanisms we show that using firms historical output for allocating permits is never optimal in a dynamic permit market setting while using firms historical emissions is optimal only in closed trading systems and only for a narrow class of allocation mechanisms instead it is possible to achieve social optimality by allocating permits based only on an external factor which is independent of output and emissions we then outline sufficient conditions for a socially optimal relative performance mechanism

risk response in the beef marketing channel a multivariate generalized arch m approach a model of the farm retail price spread for beef is specified under rational expectations in which systematic risk response on the part of marketing intermediaries is allowed the three equation structural model contains potentially time varying risk terms in margin and supply equations which i approximate and estimate using a multivariate garch in mean approach the estimated model is used to infer relative risk premia in beef margins and to simulate short run equilibrium risk effects results indicate that price risk has at times had substantial impacts on farm and retail beef prices and production

contest with pre contest investment abstract in a standard noisy contest more competition more contestants leads to lower individual equilibrium effort we show that when contestants can make pre contest investment to enhance their competency neither equilibrium investment nor individual effort is monotonic in the number of contestants individual effort may increase with the level of participation

environmental policy incentives to adopt advanced abatement technology abstract we investigate incentives through environmental policy instruments to adopt advanced abatement technology first we study the case where the regulator makes long term commitments to policy levels and does not anticipate arrival of new technology we show that taxes provide stronger incentives than permits auctioned and free permits offer identical incentives and standards may give stronger incentives than permits second we investigate scenarios where the regulator anticipates new technologies we show that with taxes and permits the regulator can induce first best outcomes if he moves after firms have invested whereas this does not always hold if he moves first

a theoretical and empirical approach to the value of information in risky markets a reply the theory of the competitive firm under price uncertainty is used to develop a money metric of a producer s willingness to pay for additional information this concept is extended to the market by formulating ex ante and ex post measures of the value of a rational expectations forecast the empirical feasibility of these measures are demonstrated by application to a simple two equation model of an agricultural market this abstract was borrowed from another version of this item

risk behavior and rational expectations in the u s broiler market this study examines the empirical implications of extending the rational expectations hypothesis reh to include price uncertainty a general estimation framework that incorporates both the restrictions on structural parameters and the variance covariance terms is developed garch time series processes are used to generate time varying expectations of both the means and the variances of exogenous variables the empirical application is with a quarterly model of the u s broiler industry the results indicate that the rational expectation of price variance is an important determinant of broiler supply a formal test indicates that the restrictions implied by the reh cannot be rejected

rent seeking contest when the prize increases with aggregate efforts the objective of this article is to investigate contests in which efforts are productive tullock s standard rent seeking model is extended by making the rent itself increase with the aggregate efforts a positive externality is thereby introduced into the contest because a contender s private effort in quest of the rent generates a benefit for other contenders coupled with a negative externality presented in the standard rent seeking model the net effect on the social efficiency of the contest is a priori ambiguous it is shown that the extended contest generates socially wasteful excessive aggregate efforts

modeling expectations of bounded prices an application to the market for corn the presence of farm programs should directly affect the expectations of producers this paper analyzes the formation of price expectations when price supports constitute an effective lower bound on the distribution of the expectations we first investigate what the expected price would be if the usual rational expectations formula is used this leads to a relationship that is not estimable we suggest two alternatives one based on a tobit approximation and the other based on a perfect prediction of when the support is going to be effective using a simplified model of the u s corn market the methodology is demonstrated and compared to an alternative method of using futures prices as the expectation of harvest price the analysis of supply response for the major u s field crops is made difficult due to government intervention in these markets this intervention has been characterized by the use of price supports acreage diversion storage incentives etc during the last thirty years many studies have analyzed producer behavior in the presence of governmental involvement such studies have typically been concerned with modeling the effect of supports and diversions in an ex post sense rather than with how producers used the knowledge of farm programs to form their expectations if producers are rational economic agents their expectations of harvest prices should be conditioned both by free market forces and the type and degree of governmental intervention in the market of course farm programs have varied in nature and extent during the past thirty years and it is doubtful that any structural model could capture their complexities in this paper we attempt to introduce rational expectations in a simplified model of the u s corn market in essence we focus on the formation of price expectations when price supports constitute an effective lower bound on the distribution of the expectations we proceed by developing a theoretical model that connects the rational expectations model with a model of bounded price variation it is shown that one representation that may characterize the corn market is a triangular structural system with endogenous switching a full information maximum likelihood estimator is proposed for the system next an empirical model is specified and estimated the model is evaluated in comparison to an augmented model that contains a futures price so that some inferences may be made concerning the rational expectations model s success in summarizing relevant market information expectations under bounded prices consider a market that may be represented by a simple supply and demand system q a pt a2w el supply function pt b qt b2xt e2t demand function 1 where p and q represent market price and quantity w and x represent supply and demand shifters and p represents the rational expectation of product price at the time production decisions are made note that this system has a familiar recursive structure when the expected price variable is specified in terms of one or more lagged prices when the restricted reduced form of the structural system is solved for in terms of the expected price and this expression is used to replace pj wallis 1980 then models similar to those of goodwin and sheifrin 1982 and shonkwiler and emerson 1982

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

price volatility and rational expectations in a sectoral framework commodity model a multivariate garch approach this article explores supply response models in a rational expectations framework with endogenous risk by using a multivariate generalized autoregressive conditional heteroskedasticity model with cholesky decomposition this approach allows the incorporation of price volatility as a risk factor into the supply response of a primary commodity sector that is composed of several markets of homogenous products the model is applied to the greek meat sector which is composed of four major meat categories that is beef lamb pork and broiler and thus the model for the entire market includes supply and demand equations for all the four meat markets which are estimated simultaneously the empirical results confirm that price volatility is a significant risk factor in greek meat production and also provide useful implications about the cost factors of production furthermore the empirical findings show that the last reform of the common agricultural policy seems to have had a negative effect on beef and lamb production in greece

the net benefits of incentive based regulation a case study of environmental standard setting economists interested in environmental safety and health regulation have long argued that decentralized incentive based or ib policies are more efficient than centralized command and control or cac approaches see charles schultze 1977 for instance these arguments generally have been based on the assumption that ib policies will accomplish the same goals as their cac counterparts but at less cost to society however some of those touting ib policies have overlooked an important point environmental workplace or even productsafety standards typically take the form of maximum permissible concentrations of harmful substances so that compliance only requires that all monitoring points or samples register readings below these critical levels for this reason ib policies typically assign a shadow price of zero to improvements that exceed the standard s while more crude cac policies generally result in overcontrol beyond the standards if there is no value to this overcontrol cac policies will not improve at all on ib approaches and will indeed be more expensive if however reduced concentrations below the level of the standards bring with them further improvements in health or the environment cac approaches will produce greater benefits than ib approaches thus a fair comparison between the two necessitates that any additional benefits associated with cac policies be offset against the cost advantages enjoyed by their ib counterparts although this possibility has been recognized by others scott atkinson and t h tietenberg 1982 for instance it is little appreciated and its empirical significance has never been ascertained that is our purpose here we do so by developing data on the costs and benefits of controlling a common air pollutant total suspended particulates or tsp in baltimore by comparing the tsp levels likely under both ib and cac approaches we are able to estimate the marginal costs and benefits associated with a variety of alternative air quality standards which take the form of maximum permissible concentrations this in turn allows us to determine the net benefits arising from the two kinds of regimes in the next section we present a simple conceptual framework for our analysis section ii describes the estimation of the costs and benefits of our hypothesized air pollution controls in baltimore section iii presents our somewhat surprising findings and section iv discusses those findings and their potential significance for regulation in the real world

alternative estimates of fed beef supply response to risk supply response models for fed beef incorporating risk by including both the mean and variance of output price are developed estimated and compared six different estimates of the mean and variance are obtained from futures prices arima processes and naive adaptive and rational expectations models empirical estimates are compared using nonnested testing procedures and indicate that the choice of the expectations model significantly influences elasticity estimates and whether supply response is positive or negative empirical evidence does not support any one model in particular suggesting that expectations are heterogenous rather than homogenous most agricultural production is characterized by a lag between the time input decisions are made and the time output actually reaches the market as a result supply response functions are based on the hypothesis that quantity produced depends on known input prices and producers expectations of output price expectations frequently have been modeled based solely on past prices examples include naive expectations adaptive expectations extensively reviewed by askari and cummings and autoregressive integrated moving average arima schemes gardner as well as others have used futures prices to estimate producers expected prices although chavas pope and kao found that futures prices are not good proxies for producers expectations

an empirical comparison of agricultural supply response mechanisms 1982 an empirical comparison of agricultural supply response mechanisms applied economics vol 14 no 2 pp 183 194

a theory of yardstick competition in the typical regulatory scheme a franchised monopoly has little incentive to reduce costs this article proposes a mechanism in which the price the regulatedfirm receives depends on the costs of identical firms in equilibrium each firm chooses a socially efficient level of cost reduction the mechanism generalizes to cover heterogeneous firms with observable differences medicare s prospective reimbursement of hospitals by using diagnostically related groups is a scheme very similar to the one outlined here

a market equilibrium analysis of the impact of risk on the u s rice industry an economic model of supply demand for u s rice suggests that increases in risk result in decreased acreage and increased marketing margins in a market equilibrium context the empirical results also suggest rice production and rice prices are more responsive to changes in risk faced by marketing firms than changes in risk faced by producing firms

a model of benchmarking regulation revisiting the efficiency of environmental standards the conventional economic argument favors the use of market based instruments over command and control regulation this viewpoint however is often limited in the description and characteristics of the latter namely environmental standards are often portrayed as lacking structured abatement incentives yet contemporary forms of command and control regulation such as standards stipulated via benchmarking have the potential to be efficient we provide a first formal analysis of environmental standards based on performance benchmarks we show that under specific conditions standards can provide efficient incentives to improve environmental performance

refunded emission payments theory distribution of costs and swedish experience of nox abatement in this paper we discuss the effect of refunding environmental charges taxes are often resisted by polluters because they imply both abatement and tax costs when charges are refunded the incentives for abatement are essentially the same as for a tax as long as there are many producers the incidence and distribution of costs is however different lower net tax payments reduce resistance from the polluters and make refunded emissions payments politically easier to implement at a sufficiently high charge level to have significant abatement effects we describe and examine the refunded emissions payment scheme as a policy instrument and compare it with taxes and permits with regard to allocative properties distribution of costs property rights and consequently the politics of implementation as an empirical example the swedish charge on nitrogen oxides is analyzed

production economics worthwhile investment abstract agricultural production economics research is examined within a broad framework of scientific development and utilization recent findings in selected areas of the subdiscipline are examined and opportunities for further fruitful inquiry are identified a few stylized facts emerge from recent work and suggest the need for much careful hypothesis testing model exploration and empirical sensitivity analysis in the future

enforcement costs and the choice of policy instruments for controlling pollution i introduction when evaluating policy instruments for controlling pollution analysts generally agree that economic incentives are superior to direct controls in terms of minimizing abatement costs however when it comes to minimizing enforcement costs there is no such agreement some analysts such as freeman et al 1973 and anderson et al 1977 argue that economic incentives would be much easier to enforce than direct controls while others such as drayton 1978 argue that they would be virtually unenforceable the debate typically centers on technical difficulties in continuously monitoring emissions and to a lesser extent on political and legal issues related to the assessment of penalties 1 an issue that has not been examined is whether there are economic reasons for enforcement costs to vary across policy instruments although there is now a sizable economic literature on the problem of noncompliance with pollution control policies there have been no attempts to formally compare enforcement costs across policy instruments 2 accordingly the purpose of this note is to examine whether there are economic grounds for arguing that enforcement costs would be lower for economic incentives than direct controls 3 the policy instruments compared are marketable permits or emissions taxes and uniform standards the instruments are compared in a setting where the penalty schedule is previously specified by some judicial or legislative body and the regulator s enforcement policy is limited to the choice of audit frequency the analysis is based on the premise that for any policy instrument that targets emissions the regulator will have to periodically monitor emissions and assess penalties for noncompliance the relevant question then is whether less frequent monitoring would be required to ensure compliance with economic incentives casual analysis suggests this should be the case economic incentives minimize aggregate abatement costs and lower abatement costs imply lower costs to firms of complying this should imply in turn that less stringent enforcement is needed to achieve compliance this argument although intuitively appealing is flawed using a simple model of pollution control with costly enforcement i show that enforcement costs narrowly defined may be higher for economic incentives for purposes of exposition the result is established in a setting where the regulator ensures each firm is fully compliant however as shown in the appendix the result generalizes to the more realistic setting where firms are partially compliant ii the model consider a group of n risk neutral firms emitting a single pollutant for simplicity the damages from the pollutant are assumed to depend only on total emissions each firm s abatement costs are given by a strictly convex function c sub i x sub i that is decreasing in emissions x sub i the firm s maximum emissions level is denoted mathematical expression omitted and is defined by mathematical expression omitted with probability p sub i a regulator audits each firm and measures its emissions if the regulator finds the firm s actual emissions x sub i exceed its allowed emissions s sub i the firm is assessed a fine of f x sub i s sub i as is common in the literature on enforcement i assume the fine schedule is previously specified e g by a legislative body 4 thus the regulator can choose the probability with which it audits firms but not the fine it assesses for noncompliance i assume the fine schedule is such that both the total fine and marginal fine are increasing in the violation size x sub i s sub i f prime is greater than 0 and f prime prime is grater than 0 because the regulator is assumed to ensure full compliance no violations occur and no fines are collected therefore enforcement costs consist solely of auditing or monitoring costs to simplify the analysis the cost of conducting an audit a is assumed to be the same across firms

testing the rational expectations hypothesis in an agricultural market a recent survey on models of agricultural supply equations listed over 500 studies in which variants of nerlove s adaptive expectations model were employed one might naively assume that the scientific evidence overwhelmingly favored the adaptive expectations hypothesis but this inference would not be warranted in particular there have been very few studies which have even attempted to estimate a rational expectations version of the traditional agricultural supply models and none that have explicitly tested the rational expectations hypothesis 2 in this paper we estimate a model of agricultural supply and demand for the chicken broiler industry under the maintained assumption of rational expectations in the sense of muth 1961 and provide a series of tests of the model specification we find that in this case the hypothesis of muth rationality receives strong support in recent years there has been increasing interest in models in which economic actors are assumed to form expectations of variables rationally for the most part empirical applications of the rational expectations hypothesis have employed single equation econometric methods these methods have permitted consistent estimation of equations under the assumption of the rational expectations hypothesis but do not allow for any explicit testing of the maintained hypothesis of rationality this paper presents estimates of a simultaneous equation model of the chicken broiler industry using maximum likelihood methods and provides a joint test of the rational expectations hypothesis and the model specification our econometric procedure is related to the recent theoretical work of wallis 1980 and combines time series analysis with traditional econometric estimation techniques under the assumption of rational expectations the model can be solved for the expected price as a function of the expected values of the exogenous variables this function can then be substituted into the model leading to a specification which contains the original endogenous and exogenous variables plus the expected values of the exogenous variables in general following this substitution the model will contain overidentifying restrictions time series analysis is utilized to generate the necessary forecasts of the exogenous variables the complete system of equations is estimated by full information maximum likelihood and the constraints are tested by a log likelihood ratio test the overidentifying constraints arise in the model because the suppliers are assumed to act as if they know both the underlying structure of the model and the stochastic processes governing the exogenous variables the two requirements of rational expectations while the expected price enters only the supply equation of our model it is necessary in the econometric formulation to specify the demand equation the instrumental variable procedures of mccallum 1976 and nelson 1975b are single equation methods and do not permit a test of the rational expectations hypothesis by specifying the complete model the additional structure imposed on the problem allows us to estimate the coefficients and test the implied restrictions there has not been universal agreement that the rational expectations hypothesis is the best theoretical device to model rational behavior according to muth s original formulation economic actors forecast endogenous variables according to the true reduced form equations of the model decanio 1979 and friedman 1979 have argued that the economic actors actually received for publication august 24 1981 revision accepted for publication march 2 1982 university of new mexico and university of california davis respectively we wish to thank g king r l huntzinger r pope and l wegge for advice on this project a nelson and e shaw contributed useful research assistance i the paper by askari and cummings 1977 provides references for these studies 2 huntzinger s 1979 paper is one of the first attempts at estimatitng a rational expectations model of agricultural supply

monitoring and enforcement of environmental regulations lessons from a natural field experiment in norway abstract relying on a small natural field experiment conducted by the norwegian environmental protection agency i estimate effects of three fundamental elements of most monitoring and enforcement practices self reporting audit frequency and specific deterrence i find evidence of under reporting of violations in firms self audits as more violations are detected in on site audits than in self audits announcing the increased audit frequency has no effect on firms compliance but an audit raises subsequent compliance substantially

estimating supply response in the presence of farm programs previous empirical research on crop supply response has given insufficient attention to the fundamentally different nature of supply response under farm programs versus competitive markets a simple theoretical model is presented which highlights the program participation option in the farmer s acreage allocation decision the model also provides the basis for different expected supply elasticities under free market and farm program regimes for corn and soybeans econometric supply estimation for corn belt states for 1948 80 using a temporally disaggregated approach confirms a greater supply elasticity for corn and a lower supply elasticity for soybeans under acreage restricting feed grain programs

dynamic incentives by environmental policy instruments a survey abstract in this paper i survey and discuss recent developments on the incentives provided by environmental policy instruments for both adoption and development of advanced abatement technology a main conclusion to be drawn from the literature is that under competitive conditions market based instruments usually perform better than command and control moreover taxes may provide stronger long term incentives than tradable permits if the regulator is myopic if the government can anticipate new technology or is able to react on it optimally regulatory policies by virtue of administered prices taxes and policies by setting quantities issuing tradable permits are almost equivalent the literature also shows that under competitive conditions there is no difference between auctioning permits and grandfathering moreover timing and commitment of environmental policy is not crucial for adoption under competitive conditions commitment has positive incentive effects however if an r d sector has market power in the presence of market imperfections the ranking of the different policy instruments is ambiguous

cap and trade taxes and distributional conflict enacting market based environmental regulation such as emissions taxes and cap and trade programs often create rents that are contested by agents in this paper we create a framework that compares social welfare from alternative market based environmental policy instruments under the presence of rent seeking we show that contrary to the commonly held view non revenue raising instruments nrris are in many cases preferable over revenue raising instruments rris we find that the choice of instrument depends on the size of a potential revenue recycling effect and the level of preassigned rents

transitional politics emerging incentive based instruments in environmental regulation abstract this paper proposes a positive theory of environmental instrument choice we study a democratic society that seeks to lower the level of pollution from industrial sources to a pre specified target the target can be implemented by one of three instruments s uniform emission standards p tradeable permits and t emission taxes the conflict of interest between special interests representing polluters and the electorate is resolved by an elected politician we characterize when each of the three policy instruments is chosen in political equilibrium and show that the transition observed in many countries from s to either p or t can be understood as a natural consequence of increasingly ambitious environmental targets

marketing margins market power and price uncertainty this paper provides a conceptual and empirical framework for analyzing marketing margins in a noncompetitive food processing industry facing output price uncertainty the framework allows the decomposition of observed margins into components reflecting the marginal cost of the processing industry oligopoly oligopsony price distortions and an output price risk component the empirical procedure is applied to a time series of spreads between wholesale pork prices and farm prices of market hogs the principal finding is that while farm wholesale margins are more consistent with competitive performance now than they were fifteen years ago the output price risk component persisted throughout the sample period

supply dynamics the case of u s broilers and turkeys supply dynamics have received considerable attention in agricultural economics nerlove 1979 askari and cummings many econometric models incorporate adjustment mechanisms that allow desired and actual states to be different usually the adjustment process is specified as a distributed lag model griliches a common expectation formula is the nerlove adaptive model which assumes that at each period the expected price is changed by an amount proportional to the most recently observed forecast error implying a geometrically declining distributed lag nerlove 1958 this model has become popular in econometric modeling partly because it ties in well with statistical theory in optimal prediction another hypothesis leading to the same reduced form except for the error term structure is the partial adjustment model griliches fromm it states that only some fixed fraction of the desired adjustment is accomplished within any particular time period it assumes the existence of some adjustment costs to explain the observed response inertia more complex expectation formulations or partial adjustment mechanisms lead to more complicated lag structures unfortunately economic theory provides little guidance to model builders on their adjustment processes the particular forms are normally selected arbitrarily by each investigator some flexible lag distributions have been applied e g almon shiller however there are statistical difficulties in distinguishing among various plausible lag models from the data alone griliches writes

modeling beef supply response and price volatility under cap reforms the case of greece abstract this study examines the supply response of the greek beef market and the possible effect of the european union s common agricultural policy cap on the greek beef sector during the period 1993 2005 a generalized autoregressive conditional heteroskedasticity garch process is used to estimate expected price and price volatility while several different symmetric asymmetric and non linear garch models are estimated the empirical results show that price volatility and feed price are important risk factors in the supply response function while the negative asymmetric price volatility that was detected implies that producers have a weak market position furthermore the empirical findings confirm that the annual premium paid by the eu to beef producers had a positive impact on the production level and also the change of the eu price support regime after 2006 is having negative effects on beef production level in greece