effluent regulation and long run optimality a regulator faced with free entry of firms is concerned not only with the implications of public policy for the discharges from a representative firm but also with the total pollution observed at the long run market equilibrium the regulator must take into account not only the effects of regulations upon the net marginal returns of the firm but must also consider the total profit of the firm and incentives for entry and exit this paper shows that effluent charges and tradeable effluent permits lead to long run optimality with entry of small firms the difference between firm payments and environmental damages is interpreted as the rent accruing to the environmental resource this result applies only to the competitive case with small polluters the analysis presented here allows a comparison and clarification of the literature on small and large polluters in a multi input framework with social damages dependent upon total effluents effluent charges are shown here to result in socially optimal entry confirming an assertion of baumol and oates 2 p 179 fn 161 and the important result of schulze and d arge 15 by taking average as well as marginal damages into account the effluent charge results in optimal firm scale levels and the correct input mix at the free entry market equilibrium the firm subject to an effluent tax will operate above or below the private minimum efficient scale depending upon whether average external costs exceed or are less than marginal external costs since public policy to reduce effluents is often directed at reducing the effluentgenerating activity some policy recommendations include a tax on the final output of the polluting firm in some theoretical analyses a relation between the output of the firm and the effluent level is identified and a pigouvian output tax is applied this approach should not be followed by policymakers since an output tax does not provide firms with the correct incentives for either input substitution or market entry it is shown that while a lump sum transfer is needed to provide correct entry incentives when a pigouvian output tax is applied no such transfer is needed if the tax is correctly applied to effluents contrary to 5 even if optimal firm scale and i thank the referees for helpful suggestions the support of the national science foundation under grant ses 82 19121 is gratefully acknowledged any errors are my responsibility 103

bankable permits for the control of environmental pollution abstract intertemporal trading of emission permits banking is often identified as one of three promising market mechanisms for controlling pollution along with averaging and trading surprisingly the efficiency properties of permit banking systems have not been investigated using a simple optimal control model this paper investigates firms incentives for banking or borrowing emission permits and compares the emission and output streams firms would choose with the socially optimal solution we find that in many cases firms will suboptimally choose excessive damage and output levels in early periods and correspondingly too few in later periods if given the opportunity to freely move emissions between time periods we propose a simple alternative trading scheme we term modified banking that counters this problem and should be no more difficult for an environmental authority to implement than a straigth banking system

statistical efficiency of double bounded dichotomous choice contingent valuation the statistical efficiency of conventional dichotomous choice contingent valuation surveys can be improved by asking each respondent a second dichotomous choice question which depends on the response to the first question if the first response is yes the second bid is some amount greater than the first bid while if the first response is no the second bid is some amount smaller this double bounded approach is shown to be asymptotically more efficient than the conventional singlebounded approach using data from a survey of californians regarding their willingness to pay for wetlands in the san joaquin valley we show that in a finite sample the gain in efficiency can be very substantial

benchmarking in the european union emissions trading system abatement incentives abstract this paper investigates abatement incentives for allowance allocation based on output and sector specific benchmarks here called output based allocation or benchmarking special attention is given to updated allocation and we assume that allowances can be traded with other sectors open cap we confirm earlier studies that output based allocation based on ex ante data provide the same abatement incentives as auction or grandfathering and also confirm that output based allocation with updated output and ex ante benchmarks provides as high abatement incentives as auction but constitutes a production subsidy however we also find that benchmarking with updated output and updated benchmarks reduces abatement incentives somewhat but less so than updated grandfathering an allocation rule where the sector cap is prescribed ex ante for instance based on historic emissions and distributed to installations in proportion to their updated production preserves full abatement incentives and avoids some of the costs associated with the determination of benchmarks however this rule also constitutes a production subsidy which decreases with industry concentration if a sector is split into smaller groups each with one benchmark per sub sector benchmarking evolves toward grandfathering since benchmarking is conditioned on production this allocation method protects production from leakage i e migrating to areas where firms face no emissions cost this may actually be the most compelling reason for choosing benchmarking

eu animal welfare policy developing a comprehensive policy framework many eu citizens are concerned about animal welfare the policy literature has responded to these concerns by suggesting a variety of policy instruments to policy makers however a gap in knowledge exists regarding which instrument should be applied under which conditions in the policy environment this article presents the results of multiple inductive case studies of eight european countries to better understand the contingencies to animal welfare policy instruments and to further complement the framework of policy instruments available to policy makers the qualitative evidence from this study is presented in the form of a policy decision tree indicating instruments likely to be effective under given conditions the findings suggest that a one size fits all solution for animal welfare in the eu is unlikely to be effective and that although a market based policy within the current eu context is in many cases inevitable the barriers are numerous and require policy instruments tailored to the specific context

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

measuring the consumer benefits of improving farm animal welfare to inform welfare labelling abstract policy makers in the european union are envisioning the introduction of a community farm animal welfare label which would allow consumers to align their consumption habits with their farm animal welfare preferences for welfare labelling to be viable the market for livestock products produced to higher welfare standards has to be sufficiently segmented with consumers having sufficiently distinct and behaviourally consistent preferences the present study investigates consumers preferences for meat produced to different welfare standards using a hypothetical welfare score data is obtained from a contingent valuation study carried out in britain the ordered probit model was estimated using bayesian inference to obtain mean willingness to pay we find decreasing marginal wtp as animal welfare levels increase and that people s preferences for different levels of farm animal welfare are sufficiently differentiated making the introduction of a labelling scheme in the form of a certified rating system appear feasible

is there an animal welfare kuznets curve abstract the concept of a kuznets curve has been applied to income inequality and to the environment the kuznets curve takes an inverted u shape with income or gdp on the x axis and environmental degradation or inequality on the y axis it is hypothesized here that an animal welfare kuznets curve may exist with harm to animals initially rising with economic growth followed by improvement in the treatment of animals after some peak value why an animal welfare kuznets curve might theoretically exist is explored empirical evidence supporting or refuting the existence of such a curve is also examined the evidence is both quantitative and qualitative in nature since some issues in welfare cannot be easily quantified the evidence and theoretical presentation explores multiple areas of concern to animals including animal agriculture the use of animals in laboratories companion animals pets and the fur industry the conclusion is that evidence is mixed with some measures indicating a turning point while other measures showing no sign of peaking improving animal welfare

on the design of optimal grandfathering schemes for emission allowances to meet its commitment under the kyoto protocol the eu plans to implement an emissions trading system whith grandfathering of allowances besides having distributional impacts the choice of the grandfathering scheme may affect efficiency if firms anticipate how future allocations depend on upcoming decisions in this paper we determine central design rules for optimal grandfathering within a simple two period model we find that for small open trading systems where allowance prices are exogenous first best second period grandfathering schemes must not depend on firm specific decisions in the first period second best schemes correspond to a ramsey rule of optimal tax differentiation and are generally based on both previous emissions and output however ofr closed emissions trading systems i e endogeneous allowance prices firstand second best rules coincide and must not depend on previous output levels they consist of an assignment proportional to the emissions in the first period plus a term which does not depend on firm specific decisions in either of the two periods

instrument choice for environmental protection when technological innovation is endogenous this paper compares qualitatively and quantitatively the welfare effects of emissions taxes auctioned emissions permits and free grandfathered permits when technological innovation is endogenous we find that there is no unambiguous case for preferring any of these policy instruments the relative welfare ranking of instruments depends on the costs of innovation the extent to which innovations can be imitated the slope and level of the marginal environmental benefit function and the number of polluting firms we illustrate the types of situations when there can be significant welfare discrepancies between the policies and when there are not

emissions trading with updated allocation effects on entry exit and distribution allocation of emissions allowances may have significant distributional and efficiency effects it is well known that cost efficiency may be achieved if allowances are auctioned or distributed in a lump sum manner e g based on emissions levels before the start of the system grandfathering bohringer and lange eur econ rev 49 2041 2055 2005 show that a cost effective outcome can also be achieved if the base year for allocation is continually updated updating given that banking and borrowing are prohibited in this paper we examine whether updating alters the entry and exit conditions for firms compared to grandfathering and how it affects profits for new and existing firms we find that the two schemes function surprisingly similar first the incentives to entry and exit are identical second the total value of free quotas to existing firms based on emissions before the system starts is also identical without any auctioning with updating initial claims for free allowances have a shorter lifetime compared to grandfathering but quota prices are higher as firms anticipate the effect of current emissions on future claims to free allowances the two effects exactly cancel each other out if there is some combination of auction and free allocation the total value of free quotas will always be highest under grandfathering if the auction rate is the same entry and exit incentives are still equal

sulfur allowance trading and the regional clean air incentives market a comparative design analysis of two major cap and trade permit programs this paper investigates in detail the design parameters of the two mostprominent us cap and trade permit program the us epa sulfur allowancetrading program and the south californian regional clean air incentivesmarket reclaim in contrast to expectations the two programs turn out to be rather different in several important design parameter choices common elements emerge primarily in the existence of an ambitious quantifiedenvironmental target mandatory use of stringent emission monitoring methodsand stiff penalties for non compliance coexisting command and controlregulations the creation of a competitive permit market structure andsome distributional concessions in the initial permit allocation generalizing from these common features we find that provisions to assurepolitical acceptance functional interdependencies and overlapping regulation are the most important influences on the design of applied cap and trade permit programs

the dynamic effects of u s food aid i introduction the effects of united states food aid on recipient country agriculture have been heatedly debated for years does food aid depress producer incentives thereby retarding output growth does it substitute for food that would otherwise be imported commercially from the donor thereby providing balance of payments relief does food aid have long run stimulative effects on recipient country commercial imports thereby developing markets for donors are there pecuniary commercial trade externalities caused by food aid wherein the donor captures either more or less than the marginal increase in recipient country commercial food imports that food aid induces although food aid may have important medium to long term effects there is a glaring absence of empirical research on these questions using dynamic modeling techniques we apply vector autoregression methods to a 1961 95 panel of data on food production food trade and program food aid shipments from the united states by far the world s largest bilateral food aid donor for the 18 countries that have most benefited from u s food aid over the past 40 plus years this analysis uncovers important intuitive multiyear patterns not previously identified in the vast literature on food aid ii the issues food aid was formalized in the united states in 1954 under public law 480 pl480 the agricultural trade development and assistance act later renamed food for peace 1 title ii emergency aid is distributed for humanitarian purposes through charities titles i and iii program food aid provide food on concessional terms that recipient governments then sell to earn revenue counterpart funds program nonemergency food aid represents the lion s share of food aid shipments historically about 80 of direct bilateral food aid compared to title ii program food aid is more fungible more commonly used for broader development purposes by recipients and for trade promotion purposes by donors and its effectiveness and desirability are more contested we study program food aid in this paper hereafter referring to it simply as food aid for the sake of brevity the multiple sometimes conflicting objectives of food aid have sparked heated debate over its efficacy in promoting either agricultural development in recipient economies or trade development for donors particularly intense debates have surrounded the questions of whether food aid 1 is additional to commercial trade volumes as the international food aid convention insists 2 establishes distribution channels and fosters consumer taste for donor country products thereby stimulating long term commercial trade or 3 depresses or stimulates recipient country food production there are no unambiguous analytical answers to these questions they demand empirical investigation while there are other conceptual debates in the literature and many over operational details we restrict our attention to these three fundamental issues the primary question to donor country agricultural producers is whether food aid creates additional commercial export opportunities under international aid agreements food aid recipient countries are obliged to maintain a normal volume of commercial food imports the usual marketing requirement or umr so as to ensure the additionality of food aid if the additionality principle is honored acker 1989 165 observes that food aid programs provide an opportunity to empty granaries and warehouses build up taste preferences for u s commodities and through the economic development consequences of our pl 480 programs build purchasing power for future commercial sales of united states agricultural commodities as researchers such as abbott and mccarthy 1982 and von braun and huddleston 1988 note however food aid commonly seems to substitute in part for commercial imports violating the additionality principle

a proximate mirror greenhouse gas rules and strategic behavior under the us clean air act the development of climate policy in the united states mirrors international developments with efforts to initiate a coordinated approach giving way to jurisdictions separately taking actions the centerpiece of us policy is regulation in the electricity sector that identifies a carbon emissions rate standard intensity standard for each state but leaves to states the design of policies including potentially the use of technology policies emissions rate averaging or cap and trade differences in policies among states within the same power market could promote predatory behavior resulting in a geographic shift in generation and investment in new resources this paper examines the coordination problem using a detailed partial equilibrium model of operations and investment we demonstrate that leading jurisdictions have available a rich set of design options including targetted output based allocation that would impose costs on neighbors and may protect against strategic predation

willingness to pay for other species well being abstract benefit cost analysis of environmental policies typically focuses on benefits to human health and well being for other species economists have attempted to measure human wtp for changes in the numbers of individuals for different types of wildlife and to preserve biodiversity when it comes to humans wtp for improvements in the quality of life for other species however the evidence is limited morbidity and quality of life considerations may be particularly important to the task of valuing non fatal harm to wildlife in the wake of an environmental disaster we argue that the other species morbidity reduction component of wtp should be calculated net of any outrage component associated with the cause of the harm this net wtp is likely to be correlated with the premium that people are willing to pay for chicken products from birds for which the quality of life has been enhanced by improved animal welfare measures this paper uses a conjoint choice stated preference survey to reveal the nature of systematic heterogeneity in preferences for humanely raised versus conventionally raised chicken we also use latent class analysis to distinguish between two classes of people those who are willing to pay a premium for humanely raised chicken and those who are not

a calibrated auction conjoint valuation method valuing pork and eggs produced under differing animal welfare conditions this paper develops a valuation method which generates consistent and systematic estimates of people s preferences for complex multi attribute goods by inextricably linking auction bids with conjoint ratings the advantage of the valuation approach is that it permits the estimation of people s values for many potential goods allows one to decompose people s values for a good into its sub components and permits the study of preference heterogeneity without distributional assumptions we apply the method to an important and increasingly controversial topic animal welfare the method is used to determine people s preferences for eggs and pork produced from different production systems data from experiments conducted in three diverse u s locations chicago il dallas tx and wilmington nc indicates that people are on average willing to pay 0 95 more for a dozen eggs raised in an aviary pasture system vs a cage system and are willing to pay 2 02 more for two pounds of pork chops raised in a pasture system as opposed to a crate system

international emissions trading with endogenous allowance choices abstract this paper compares endogenous choices of tradable and non tradable emission allowances by non cooperative countries i find that the cost savings of trading do not necessarily lead to less pollution in particular environmentally more concerned countries usually choose less allowances if these are tradable but this may be offset by the choice of more allowances on the side of environmentally less concerned countries moreover if the establishment of a trading system requires the unanimous approval of all countries there may be no agreement on trading even if it were to lead to less pollution overall conversely a trading system may find unanimous approval even if it induces more pollution

incentives and prices in an emissions trading scheme with updating abstract emissions trading schemes where allocations are based on updated baseline emissions give firms less incentive to reduce emissions for a given quota or allowance price nevertheless according to bohringer and lange on the design of optimal grandfathering schemes for emission allowances europ econ rev 49 2005 2041 2055 such allocation schemes are cost effective if the system is closed and allocation rules are identical across firms in this paper we show that the cost effective solution may be infeasible if marginal abatement costs grow too fast moreover if a price cap or banking borrowing is introduced the abatement profile is no longer the same as in the case with an auction or lump sum allocation in addition we show that with allocation based on updated emissions the quota price will always exceed marginal abatement costs possibly misguiding policy makers and investors about abatement costs numerical simulations indicate that the quota price most likely will be several times higher than marginal abatement costs unless a significant share of allowances is auctioned

mitigation incentives with climate finance and treaty options abstract future greenhouse gas ghg mitigation action of current non climate policy np countries is considered to take two alternative forms 1 climate finance payments received in return for future reductions in its ghg emissions below a defined baseline and 2 join a climate treaty whereby the required emissions reductions are formally binding it is assumed that baselines defining climate finance payments and required emissions reductions under a treaty depend positively on current emissions it is then shown that making such future options available reduces current ghg mitigation in np countries leading to higher emissions in the short run this effect is stronger when future climate finance payments are higher the required relative emissions reductions under a treaty are greater when commitments under a treaty are longer lasting and mitigation targets depend more on current emissions such short run increases in emissions can sometimes more than fully eliminate the effect of the subsequent policy when climate finance and treaties are both future alternatives more generous climate finance can make it harder and more expensive to induce the country to join a climate treaty

valuing an eu animal welfare label using experimental auctions the aim of this article is to determine consumers valuation for an eu animal welfare eu caw label for products providing higher animal welfare standards than the current legal requirements using revealed preference data from random nth price auction mechanism and two auction procedures our results generally suggest that consumers are willing to pay a premium for an eu animal welfare eu caw label for cured ham this finding is consistent in both the endowment and full bidding auction approaches we employed in our experiments conducted in spain the average premium that consumers are willing to pay for a cured ham with the eu caw label ranges between 19 and 23 of the average price of the regular cured ham that is currently available in supermarkets

emissions trading with offset markets and free quota allocations we study optimal climate policy for a policy bloc of countries facing a market where emissions offsets can be purchased from a non policy fringe of countries such as with the cdm policy bloc firms benefit from free quota allocations which are updated according to either firms past emissions or outputs we show that the resulting abatement and its allocation between policy bloc and fringe are both inefficient when all quotas are traded freely at a single price the policy bloc chooses to either not constrain the offset market leading to suboptimal policy bloc mitigation or ban offsets completely the former latter case occurs when free allocation of quotas is not very generous and the offset market is large small it is preferable for policy bloc countries governments to instead buy offsets directly from the fringe at a quota price below marginal damage cost of emissions while the policy bloc quota price will be above this cost with maximization of global welfare and a unified quota price this price is higher and offsets constrained in fewer cases but the solution still inefficient full efficiency then requires a higher quota price in the policy bloc than in the fringe

food safety issues and the bse scare some lessons from the french case abstract the bovine spongiform encephalopathy bse scare began after the uk minister of health admitted a possible link between the bse prion and the creutzfeldt jakob disease contaminating humans the paper outlines a survey conducted in the area of rennes to analyse consumer behaviour after the bse crisis a contingent scenario was proposed to determine the willingness to pay wtp for beef which should not transmit cjd using a mix of the referendum method and the bidding process the variables considered as main determinants of the wtp have been selected the study concludes with the interests and limits of the method used and the implications of the bse scare on food policy in fact the mad cow disease raises the problem of loss of public confidence and the means to restore it consumers are waiting for a greater transparency or traceability and according to the survey would accept to pay for it

a ten year rule to guide the allocation of eu emission allowances abstract member states in the european union eu are responsible for national allocation plans governing the initial distribution of emission allowances in the co2 emission trading system including rules governing allocations to installations that close and to new entrants the european commission has provided guidelines to discourage the use of allocation methodologies that provide incentives affecting firms compliance behavior for example by rewarding one type of compliance investment over another we find that the treatment of closures and new entrants by member states is inconsistent with the general guidelines provided by the eu we propose stronger eu guidance regarding closures and new entrants a more precise compensation criterion on which to justify free allocations and a ten year rule as a component of future eu policy that can guide a transition from current practice to an approach that places greater weight on efficiency

do fair trade and eco labels in coffee wake up the consumer conscience abstract in this study a face to face survey was conducted in order to reveal consumer preferences for ethical and environmentally sound labeling programs in coffee valuation questions regarding the fair trade shade grown and organic coffee labels were asked using a payment card format after consumers were previously informed about each of the labeling programs results suggest that consumers are very receptive toward both fair trade and shade grown coffee labels and consequently are willing to pay higher premiums for these labeling programs than for the organic coffee

the environment as a factor of production the authors develop a model of environmental resource use in production with an empirical analysis of how electric power companies consume and bank sulfur dioxide pollution permits the model considers emissions fuels and labor as variable inputs with quasi fixed inputs of permits and capital incorporating information from permit markets allows the authors to distinguish between user costs and asset shadow values their findings indicate that firms are holding stocks of pollution permits for reasons other than short term cost savings the results also reveal substantial substitution possibilities between emissions permits stocks and other factors of production the authors speculate that anticipated secondary markets for carbon offset inventories related to the flexibility mechanisms of the kyoto protocol will have similar effects for greenhouse gas emitting firms

farm animal welfare and food policy abstract legislation has been the main policy approach for protecting the welfare of farm animals the use of legislation raises issues such as whose preferences the legislation reflects and whether the preferences of some people in society should constrain the food consumption choices of others the paper outlines a survey in great britain which sought to measure people s willingness to pay to support legislation to ban the use of battery cages for egg production in the european union eu it discusses the implications of the survey findings for animal welfare and food policy it concludes that legislation which constrains food consumption choices may be justified where there are significant negative animal welfare externalities as a result of livestock product consumption however the combination of legislation and producer subsidies may provide an appropriate policy which improves animal welfare without directly constraining food consumption choice and could help to achieve other policy aims regarding agriculture in the eu

using history dependence to design a dynamic tradeable quota system under market imperfections a transferable quota system is analysed in a two period model with market power so far the management mechanisms presented in the literature to remedy market power have either not succeeded in securing efficiency in the distribution of quota within and across time periods or have resulted in only one of the two inefficiencies being eliminated in this paper a new mechanism is introduced where allocation of quota is made dependent upon historic quota acquisitions this opens for a trade off between distributional and time efficiency or under specific circumstances securing overall efficiency

allocation of co2 emissions permits a general equilibrium analysis of policy instruments what are the effects of different ways of allocating co2 emissions permits under a tradable permit scheme numerical simulations show that using the permit revenue to lower existing taxes implies by far the lowest welfare cost but also a large reduction in employment in energy intensive sectors and substantial stranded costs grandfathering the permits compensates owners for losses on stranded investments but comes at a welfare cost and does not mitigate the adjustment imposed on the economy finally distributing the permits according to market shares reduces the degree of sectoral adjustment but also comes at a high welfare cost

welfare effects of tied food aid abstract an important part of the overall u s aid program is public law 480 food aid the design of the program seeks to satisfy numerous and often conflicting objectives several constraints have been placed on the use by recipient countries of that aid to insure that the intentions of the program are achieved this paper examines the implications for recipient country welfare of both the traditional and the proposed restrictions on pl480 aid it also seeks to clarify the interpretation of empirical work on the effects of this aid it is shown that the net value of such commodity tied aid is simply the grant component of the subsidized sale and may easily be realized by substituting food aid imports for commercial imports restrictions which prevent aid recipients from doing so are costly to the recipient and could lead even to immuserization empirical evidence obtained by others is consistent with the notion that such restrictions are circumvented where possible by food aid recipients the results presented indicate that a schultzian disincentive effect is characteristic of a closed economy typical interventions on the part of recipient country governments do not effectively reclose the economy hence open economy models are more appropriate frameworks for evaluating the effects of pl480 aid

output based allocation of emissions permits for mitigating tax and trade interactions the allocation of tradable emissions permits has important efficiency as well as distributional effects when tax and trade distortions are taken into account we compare different rules for allocating carbon allowances within sectors lumpsum grandfathering output based allocation oba auctioning and among sectors historical emissions or value added shares the output subsidies implicit in oba mitigate tax interactions unlike grand fathering oba with sectoral distributions based on value added is similar to revenue recycling with auctioning oba based on historical emissions supports heavier polluters more effectively counter acting carbon leakage but at higher welfare costs less energy intensive sectors are also sensitive to allocation rules

citizens consumers and farm animal welfare a meta analysis of willingness to pay studies the sustainable intensification of animal production systems is increasing as a consequence of increased demand for foods originating from animals production diseases are particularly endemic in intensive production systems and can negatively impact upon farm animal welfare there is an increasing need to develop policies regarding animal production diseases sustainable intensification and animal welfare which incorporate consumer priorities as well as technical assessments of farm animal welfare consumers and or citizens may have concerns about intensive production systems and whether animal production disease represent a barrier to consumer acceptance of their increased use there is a considerable body of research focused on consumer willingness to pay wtp for improved animal welfare it is not clear how this relates specifically to a preference for reduced animal production disease incidence in animal production systems a systematic review and meta analysis were conducted to establish the publics wtp for farm animal welfare with a focus on production diseases which arise in intensive systems systematic review methodology combined with data synthesis was applied to integrate existing knowledge regarding consumer wtp for animal welfare and reduced incidence of animal production diseases multiple databases were searched to identify relevant studies a screening process using a set of pre determined inclusion criteria identified 54 studies with the strength of evidence and uncertainty for each study being assessed a random effects meta analysis was used to explore heterogeneity in relation to a number of factors with a cumulative meta analysis conducted to establish changes in wtp over time the results indicated a small positive wtp 0 63 standard deviations for farm animal welfare varying in relation to a number of factors including animal type and region socio demographic characteristics explained the most variation in the data an evidence gap was highlighted in relation to reduced wtp for specific production diseases associated with the intensification of production with only 4 of the 54 studies identified being related to this a combination of market and government based policy solutions appears to be the best solution for improving farm animal welfare standards in the future enabling the diverse public preferences to be taken into consideration