regressive sin taxes with an application to the optimal soda tax a common objection to sin taxes corrective taxes on goods that are thought to be overconsumed such as cigarettes alcohol and sugary drinks is that they often fall disproportionately on low income consumers this paper studies the interaction between corrective and redistributive motives in a general optimal taxation framework and delivers empirically implementable formulas for sufficient statistics for the optimal commodity tax the optimal sin tax is increasing in the price elasticity of demand increasing in the degree to which lower income consumers are more biased or more elastic to the tax decreasing in the extent to which consumption is concentrated among the poor and decreasing in income effects because income effects imply that commodity taxes create labor supply distortions contrary to common intuitions stronger preferences for redistribution can increase the optimal sin tax if lower income consumers are more responsive to taxes or are more biased as an application we estimate the optimal nationwide tax on sugar sweetened beverages using nielsen homescan data and a specially designed survey measuring nutrition knowledge and self control holding federal income tax rates constant our estimates imply an optimal federal sugar sweetened beverage tax of 1 to 2 1 cents per ounce although optimal city level taxes could be as much as 60 lower due to cross border shopping

brand pricing and advertising industrial organization theory posits that market structure influences a firm s opportunity to raise its product s price above its marginal cost most studies have explained the structure performance relationship in terms of the ability of firms to collude in an industry protected by barriers to entry an alternative theory is that the structure performance relationship results from leading firms relative efficiency a third explanation one that has not previously been explored is related to the positive effect of brand advertising on brand price in consumer markets the purpose of much advertising is to convince buyers that the brands they are purchasing provide the best value in some products consumers preferences for high priced brands have persisted in spite of credible evidence that competing brands are physically identical concentrated lemon juice evaporated milk and household bleach alternative brands are packaged under identical specifications by the same manufacturers cookies or buyers cannot distinguish their brand from lower priced brands in blind taste tests beer the results of structure performance studies of food manufacturing industries generally are similar to those found in other industries collins and preston 3 found that sales concentration was positively related to industry price cost margins across 32 food industries parker and connor 21 found that advertising intensity also was positively related to food industry price cost margins rogers 26 concluded that the impacts of advertising intensity and concentration on food industry price cost margins had increased between 1954 and 1977 the federal trade commission 10 imel and helmberger 14 and ravenscraft 25 similarly conclude that profit rates of food manufacturing firms reflect the structure of the markets they serve and their relative position in those markets

behavioral hazard in health insurance a fundamental implication of standard moral hazard models is overuse of low value medical care because copays are lower than costs in these models the demand curve alone can be used to make welfare statements a fact relied on by much empirical work there is ample evidence though that people misuse care for a different reason mistakes or behavioral hazard much high value care is underused even when patient costs are low and some useless care is bought even when patients face the full cost in the presence of behavioral hazard welfare calculations using only the demand curve can be off by orders of magnitude or even be the wrong sign we derive optimal copay formulas that incorporate both moral and behavioral hazard providing a theoretical foundation for value based insurance design and a way to interpret behavioral nudges once behavioral hazard is taken into account health insurance can do more than just provide financial protection it can also improve health care efficiency jel codes d03 i12 i13 i30 i38

will business cycles in the euro area converge a critical survey of empirical research this survey of business cycle synchronization in the european monetary union focuses on two issues have business cycles become more similar and which factors drive business cycle synchronization we conclude that business cycles in the euro area have gone through periods of both convergence and divergence still there is quite some evidence that during the 1990s business cycle synchronization in the euro area has increased higher trade intensity is found to lead to more synchronization but the point estimates vary widely the evidence for other factors affecting business cycle synchronization is very mixed

the low carbon technology characteristics of china s ferrous metal industry abstract the ferrous metal industry is the largest energy consuming industrial sector in china this paper examines the low carbon production characteristics of this industry during the period 1980 2013 we employ the duality theory of the weighted russell directional distance function to propose a general procedure for modeling production characteristics with carbon emissions being considered the undesirable output using the weighted russell directional distance function model we measure the carbon adjusted technical efficiency and environmental regulatory costs for this industry to investigate policy effects we test the porter hypothesis using the granger causality between regulatory cost and technical efficiency by using the dual model of weighted russell directional distance function we estimate the carbon shadow pricing and inter factor substitution possibilities results show that the carbon adjusted technical efficiency and environmental regulation costs of the chinese ferrous metal industry have significantly increased in recent decades however the latter does not significantly cause the improvement of former the indirect morishima elasticities of substitution reflect that the increase of fixed assets will effectively improve the carbon emissions performance of the chinese ferrous metal industry finally some policy implications are suggested

do pharmacists buy bayer informed shoppers and the brand premium we estimate the effect of information and expertise on consumers willingness to pay for national brands in physically homogeneous product categories in a detailed case study of headache remedies we find that more informed or expert consumers are less likely to pay extra to buy national brands with pharmacists choosing them over store brands only 9 percent of the time compared to 26 percent of the time for the average consumer in a similar case study of pantry staples such as salt and sugar we show that chefs devote 12 percentage points less of their purchases to national brands than demographically similar nonchefs we extend our analysis to cover 50 retail health categories and 241 food and drink categories the results suggest that misinformation and related consumer mistakes explain a sizable share of the brand premium for health products and a much smaller share for most food and drink products we tie our estimates together using a stylized model of demand and pricing

a search cost model of obfuscation this article develops models in which obfuscation is individually rational for oligopolistic firms firms sell a homogeneous good to rational consumers who incur search costs to learn prices search costs are endogenized by allowing obfuscation firms have an unobservable action that increases the time needed to learn their price one model involves search costs convex in shopping time we show that slight convexity can dramatically alter the equilibrium price distribution a second model examines an informational linkage between current and future search costs consumers are uncertain about a component of search costs here a signal jamming mechanism can lead to equilibrium obfuscation

who participates in household scanning panels we compare two widely used household scanning panels maintained by the nielsen company and information resources inc to a random sample of the u s population results indicate that the demographic characteristics of the random sample more closely match the census bureau data than the household scanning panels we also show that after controlling for demographic differences participants in the household scanning panels are slightly more price sensitive than participants in the random sample the two household scanning panels yield similar results in relation to one another which suggests that the household scanning panels may suffer from sample selection and participation biases

price competition under limited comparability this paper studies market competition when firms can influence consumers ability to compare market alternatives through their choice of price formats we introduce random graphs as a tool for modelling limited comparability of formats our main results concern the interaction between firms equilibrium price and format decisions and its implications for industry profits and consumer switching rates we show that narrow regulatory interventions that aim to facilitate comparisons may have adverse consequences for consumer welfare finally we argue that our limited comparability approach provides a new perspective into the phenomenon of product differentiation

the hodrick prescott filter the slutzky effect and the distortionary effect of filters abstract i construct a metric based on optimal filtering for measuring the distortionary effect of business cycle filters the distortionary effect of a filter depends both on the power transfer function of the filter and on the spectrum of the filtered time series the metric is used for two purposes first to determine the optimal value of the smoothing parameter in the hodrick prescott filter hp filter secondly to measure the size of distortions of ten different filters the slutzky effect is a special case of a more general pattern of distortions and it is shown that the alleged slutzky effect of the hp filter is due to an insufficient distinction between the effect of filtering with an ideal high pass filter and the distortionary effect of the hp filter

financial contagion and international portfolio flows financial contagion is an issue of interest to policymakers and portfolio managers in the presence of contagion the benefits of geographical diversification may be overstated contagion is defined independently of changes in macroeconomic fundamentals it corresponds to a situation in which shocks in one country spread to another country in a significantly more pronounced manner than during quiet times in the study reported here i attempted to measure contagion from daily cross border portfolio flows using data from state street bank and trust company i constructed three indexes for 1996 through 2000 i found little statistical evidence of contagion but the weighted index that measured the contagiousness of flows reached its four year low in august 1998 suggesting that the russian crisis was characterized by both contagion and large aggregate outflows i also found that contagion appears to be regional and that the developed countries seem to be sheltered from contagion

uninformed votes information effects in presidential elections theory recent scholarship has emphasized the potential importance of cues information shortcuts and statistical aggregation processes in allowing relatively uninformed citizens to act individually or collectively as if they were fully informed hypotheses uninformed voters successfully use cues and information shortcuts to behave as if they were fully informed failing that individual deviations from fully informed voting cancel out in a mass electorate producing the same aggregate election outcome as if voters were fully informed methods hypothetical fully informed vote choices are imputed to individual voters using the observed relationship between political information and vote choices for voters with similar social and demographic characteristics estimated by probit analysis of data from national election study surveys conducted after the six most recent united states presidential elections results both hypotheses are clearly disconfirmed at the individual level the average deviation of actual vote probabilities from hypothetical fully informed vote probabilities was about ten percentage points in the electorate as a whole these deviations were significantly diluted by aggregation but by no means eliminated incumbent presidents did almost five percentage points better and democratic candidates did almost two percentage points better than they would have if voters had in fact been fully informed

the morphology of price dispersion this paper is a study of the shape and structure of the distribution of prices at which an identical good is sold in a given market and time period we find that the typical price distribution is symmetric and leptokurtic with a standard deviation between 19 and 36 only 10 of the variance of prices is due to variation in the expensiveness of the stores at which a good is sold while the remaining 90 is due in approximately equal parts to differences in the average price of a good across equally expensive stores and to differences in the price of a good across transactions at the same store we show that the distribution of prices that households pay for the same bundle of goods is approximately normal with a standard deviation between 9 and 14 half of this dispersion is due to differences in the expensiveness of the stores where households shop while the other half is mostly due to differences in households choices of which goods to purchase at which stores we find that households with fewer employed members pay lower prices and do so by visiting a larger number of stores rather than by shopping more frequently

life cycle prices and production we use scanner data and time diaries to document how households substitute time for money through shopping and home production we document substantial heterogeneity in prices paid for identical goods for the same area and time with older households shopping the most and paying the lowest prices doubling shopping frequency lowers a good s price by 7 to 10 percent we estimate the shopper s price of time and use this series to estimate an elasticity of substitution between time and goods in home production of roughly 1 8 the observed life cycle time allocation implies a consumption series that differs markedly from expenditures

regional energy efficiency carbon emission performance and technology gaps in china a meta frontier non radial directional distance function analysis abstract at present china is the largest primary energy consumer and carbon emitter in the world meantime china is a large transitional economy with significant regional gaps against such backgrounds the calculated results of energy and carbon performance indicators may be biased without considering heterogeneity across regions to this end after incorporating region heterogeneity this paper provides detailed information regarding energy efficiency carbon emission performance and the potential of carbon emission reductions from regional perspectives which may be important and useful for policy makers our main findings are as follows firstly there is significant group heterogeneity across regions in china in terms of energy efficiency and carbon emission performance secondly there are no considerable differences between total factor and single factor performance indices since there is limited substitutability between energy inputs and other production inputs finally significant carbon emission reductions can be made by catching up for regions with low energy efficiency and carbon emission performance looking ahead the chinese government should adopt measures to promote improvements in terms of energy efficiency and carbon emission performance in the short term

the bidder s curse reply in our paper the bidder s curse malmendier and lee 2011 we introduce a novel research design to identify overbidding on ebay we compare the final price in an auction to the fixed price at which the same item was simultaneously available on ebay during the sample period overbidding was surprisingly prevalent affecting around 40 50 percent of auctions across different datasets the overbidding percentages ranged from 0 to 72 percent for different item categories the paper shows that such widespread overbidding is generated by a small number of bidders auctions emerge as a tool to fish for fools whose bids generate high final prices cf malmendier and szeidl 2012 our research design has been used or discussed in a number of papers 1 including schneider 2016 schneider applies the comparison to another dataset of dvd auctions he finds a very similar range of overbidding percentages between 0 percent and 69 percent without shipping cost and 0 percent to 83 percent with shipping cost depending on the movie and 23 percent on average the emphasis of the paper however is different schneider points to users inability to inspect all relevant ebay listings of an item e g to click page down or next page but also to use all relevant search terms he proposes that these failings indicate that traditional

income and wealth effects on private label demand evidence from the great recession we measure the causal effects of income and wealth on the demand for private label products prior research suggests that these effects are large and in particular that private label demand rises during recessions our empirical analysis is based on a comprehensive household level transactions database matched with price information from store level scanner data and wealth data based on local house value indices the great recession provides a key source of the variation in our data showing a large and geographically diverse impact on household incomes over time we estimate income and wealth effects using within variation of income at the household level and wealth at the zip code level our estimates can be interpreted as income and wealth effects consistent with a consumer demand model based on utility maximization we establish a precisely measured negative effect of income on private label shares the effect of wealth is negative but not precisely measured however the estimated effect sizes

comovement in gdp trends and cycles among trading partners abstract it has long been recognized that business cycle comovement is greater between countries that trade more intensively with one another however nations face shocks to both the cyclical and trend components of their gdp series contrary to the result for cyclical fluctuations we find comovement of shocks to the trend component of real gdp is weaker among countries that trade more intensively with one another we simulate changes in ten year output growth correlations corresponding to the estimated effects of trade and show that the impact of trade on trend comovement is quantitatively more important than its effect on cyclical comovement

a simple theory of advertising as a good or bad our analysis treats advertisements and the goods advertised as complements in stable metautility functions and generates new results for advertising by building on and extending the general analysis of complements by assimilating the theory of advertising into the theory of complements we avoid the special approaches to advertising found in many studies that place obstacles in the way of understanding the effects of advertising we also use this approach to evaluate advertising from a welfare perspective whether there is excessive or too little advertising depends on several variables the effects on consumer utility the degree of competition in the market for advertised goods the induced changes in prices and outputs of advertised goods and whether advertising is sold to consumers

detrending stylized facts and the business cycle the stylized facts of macroeconomic time series can be presented by fitting structural time series models within this framework we analyse the consequences of the widely used detrending technique popularised by hodrick and prescott 1980 it is shown that mechanical detrending based on the hodrick prescott filter can lead investigators to report spurious cyclical behaviour and this point is illustrated with empirical examples structural time series models also allow investigators to deal explicitly with seasonal and irregular movements that may distort estimated cyclical components finally the structural framework provides a basis for exposing the limitations of arima methodology and models based on a deterministic trend with a single break

external factors in emerging market recoveries an empirical investigation abstract we estimate conditional duration models to analyse recovery processes in emerging market economies our reduced form specification is parsimonious as we focus on exogenous factors such as the effect of growth in the us eu and japan on the prospects for recovery in emerging market economies experiencing recessions the model confirms the importance of external factors in recovery processes however the short run effect of japanese growth on recovery prospects is unconventional weak economic conditions in japan turn out to facilitate recoveries

shrouded attributes consumer myopia and information suppression in competitive markets bayesian consumers infer that hidden add on prices e g the cost of ink for a printer are likely to be high prices if consumers are bayesian firms will not shroud information in equilibrium however shrouding may occur in an economy with some myopic or unaware consumers such shrouding creates an inefficiency which firms may have an incentive to eliminate by educating their competitors customers however if add ons have close substitutes a curse of debiasing arises and firms will not be able to profitably debias consumers by unshrouding add ons in equilibrium two kinds of exploitation coexist optimizing firms exploit myopic consumers through marketing schemes that shroud high priced add ons in turn sophisticated consumers exploit these marketing schemes it is not possible to profitably drive away the business of sophisticates it is also not possible to profitably lure either myopes or sophisticates to nonexploitative firms we show that informational shrouding flourishes even in highly competitive markets even in markets with costless advertising and even when the shrouding generates allocational inefficiencies

health insurance for humans information frictions plan choice and consumer welfare traditional models of insurance choice are predicated on fully informed and rational consumers protecting themselves from exposure to financial risk in practice choosing an insurance plan is a complicated decision often made without full information in this paper we combine new administrative data on health plan choices and claims with unique survey data on consumer information to identify risk preferences information frictions and hassle costs our additional friction measures are important predictors of choices and meaningfully impact risk preference estimates we study the implications of counterfactual insurance allocations to illustrate the importance of distinguishing between these micro foundations for welfare analysis

asset correlations in single factor credit risk models an empirical investigation abstractthe internal ratings based irb approach based on a single risk factor model was designed by the basel committee on banking supervision bcbs to determine banks regulatory credit risk capital key inputs of the model asset correlations are prescribed by the regulator relevant banks must use them for capital determination to ascertain whether these correlations are too onerous or too lenient empirical asset correlations embedded in loss data spanning different loss milieu were backed out of the regulatory model static and rolling correlations over a period of time were compared with the prescribed correlations for developed and developing economies and found to be significantly more conservative

beyond revealed preference choice theoretic foundations for behavioral welfare economics we propose a broad generalization of standard choice theoretic welfare economics that encompasses a wide variety of nonstandard behavioral models our approach exploits the coherent aspects of choice that those positive models typically attempt to capture it replaces the standard revealed preference relation with an unambiguous choice relation roughly x is strictly unambiguously chosen over y written xp y iff y is never chosen when x is available under weak assumptions p is acyclic and therefore suitable for welfare analysis it is also the most discerning welfare criterion that never overrules choice the resulting framework generates natural counterparts for the standard tools of applied welfare economics and is easily applied in the context of specific behavioral theories with novel implications though not universally discerning it lends itself to principled refinements

money output and inflation in the longer term major industrial countries 1880 2001 i introduction the empirical role of money growth in the macroeconomy has been studied by many researchers using different data and methods the most prominent studies focusing on the quantity theory of money are those of friedman and schwartz 1963 1982 using data averaged over the phases of the business cycle in order to capture longer run movements with u s and u k data back to 1867 the study by mccandless and weber 2001 is a representative example for a different approach for 110 countries in the post wwii period longer run growth rates are approximated by growth of a variable over a 30 year period average growth rates 1 the problem with phase averaging is that it does not deal with possible nonstationarity of the data 2 the problem with growth averages over long periods while informative to a degree is that they have limitations too it is impossible to assess the timing of movements in these variables 3 in the frequency domain the long run is associated with frequency zero which in our terminology is the long run trend previous studies in the frequency domain on the long run neutrality of money at zero frequency include the studies of lucas 1980 and geweke 1986 the theory of spectral analysis provides a rigorous framework for extracting specific frequency bands from the data instead of considering only frequency zero stock and watson 1998 applied the band pass filter of baxter and king 1999 to extract cycles frequency bands for u s data and focused on the business cycle and on mostly the post wwii period christiano and fitzgerald 2003 proposed an improved band pass filter and provided an application to the longer run relation of money and inflation for bands of 8 20 years and 20 40 years in the united states from 1900 to 1997 4 the usefulness of monetary aggregates for conducting monetary policy has been seriously called into question because of the instability of money demand a prominent empirical study is that of estrella and mishkin 1997 recent mainstream new keynesian models have no explicit role for money woodford 2008 a contrasting view is that the longer term role of money is still of relevance for monetary policy the european central bank explicitly emphasizes a supporting role that monetary aggregates should play in order to provide an anchor for inflation expectations hafer haslag and jones 2007 issing 2006 king 2002 nelson 2003 christiano motto and rostagno 2007 provided a theoretical new keynesian model where inflation expectations lose their anchor unless money is monitored and reacted to also beck and wieland 2008 presented a new keynesian model where cross checking with money growth movements improves inflation control similarly assenmacher wesche and gerlach 2006 2007 found a significant role for a low frequency low pass filtered component of money in the empirical new keynesian phillips curve equation 5 in the spirit of friedman 1961 we use long time spans so that our results are unlikely to be because of a specific policy rule in place in a given period we have 122 years of annual data from 1880 to 2001 before the introduction of the euro in 2002 we have real gross domestic product gdp money and consumer price indices cpis with no gaps for 11 industrialized countries 6 the countries included in our study differ in such terms as their institutions fiscal and monetary policies and economic growth rates nonetheless at least in peace time they were similar in generally having comparatively free markets in which prices and interest rates were determined our aim is to apply analytic methods that are free from economic and statistical models as much as possible in order to explore empirical regularities or stylized facts in the data also the focus of our research is the longer run we employ band pass filters to pick out cycles from each time series that last 8 40 years that is the longer term component

ask your doctor direct to consumer advertising of pharmaceuticals we measure the impact of direct to consumer television advertising dtca by drug manufacturers our identification strategy exploits shocks to local advertising markets generated by the political advertising cycle and a regulatory intervention affecting a single product we find evidence of significant business stealing effects among branded advertised drugs in addition we show positive spillovers from drug advertisements to non advertised competitors in the same class we decompose the effect and show it is primarily due to new customers finally we provide evidence that dtca is cost effective from a societal standpoint in our setting

cellular service demand biased beliefs learning and bill shock by april 2013 the fcc s recent bill shock agreement with cellular carriers requires consumers be notied when exceeding usage allowances will the agreement help or hurt consumers to answer this question we estimate a model of consumer plan choice usage and learning using a panel of cellular bills our model predicts that the agreement will lower average consumer welfare by 2 per year because rms will respond by raising monthly fees our approach is based on novel evidence that consumers are inattentive to past usage meaning that bill shock alerts are informative and advances structural modeling of demand in situations where multipart taris induce marginal price uncertainty additionally our model estimates show that an

inflation at the household level abstract we use scanner data to estimate inflation rates at the household level households inflation rates have an annual interquartile range of 6 2 9 0 percentage points most of the heterogeneity comes not from variation in broadly defined consumption bundles but from variation in prices paid for the same types of goods lower income households experience higher inflation but most cross sectional variation is uncorrelated with observables households deviations from aggregate inflation exhibit only slightly negative serial correlation almost all variability in a household s inflation rate comes from variability in household level prices relative to average prices not from variability in aggregate inflation

competition and product quality in the supermarket industry this article analyzes the effect of competition on a supermarket firm s incentive to provide product quality in the supermarket industry product availability is an important measure of quality using u s consumer price index microdata to track inventory shortfalls i find that stores facing more intense competition have fewer shortfalls competition from walmart the most significant shock to industry market structure in half a century decreased shortfalls among large chains by about a third the risk that customers will switch stores appears to provide competitors with a strong incentive to invest in product quality

electricity forward curves with thin granularity theory and empirical evidence in the hourly epexspot market we propose a constructive definition of electricity forward price curve with cross sectional timescales featuring hourly frequency on the curve is jointly consistent with both risk neutral market information represented by baseload and peakload futures quotes and historical market information as mirrored by periodical patterns exhibited by the time series of day ahead prices from a methodological standpoint we combine nonparametric filtering with monotone convex interpolation such that the resulting forward curve is pathwise smooth and monotonic cross sectionally stable and time local from an empirical standpoint we exhibit these features in the context of epex spot and eex derivative markets we perform a backtesting analysis to assess the relative quality of our forward curve estimate compared to the benchmark market model of benth koekebakker and ollmar 2007

product differentiation search costs and competition in the mutual fund industry a case study of s p 500 index funds we investigate the role that non portfolio fund differentiation and information search frictions play in creating two salient features of the mutual fund industry the large number of funds and the sizeable dispersion in fund fees in a case study we find that despite the financial homogeneity of s p 500 index funds this sector exhibits the fund proliferation and fee dispersion observed in the broader industry we show how extra portfolio mechanisms explain these features these mechanisms also suggest an explanation for the puzzling late 1990s shift in sector assets to more expensive and often newly entered funds an influx of highinformation cost novice investors

total factor carbon emission performance of fossil fuel power plants in china a metafrontier non radial malmquist index analysis article i nfo this paper proposes the metafrontier non radial malmquist co2 emission performance index mnmcpi for measuring dynamic changes in total factor co2 emission performance over time the mnmcpi method allows for the incorporation of group heterogeneity and non radial slack into the previously introduced malmquist co2 emission performance index mcpi we derive the mnmcpi by solving several non radial data envelop ment analysis dea models we decompose the mnmcpi into an efficiency change ec index a best practice gap change bpc index and a technology gap change tgc index and based on the proposed indices we examine the dynamic changes in co2 emission performance and its decomposition of fossil fuel power plants in china for the 2005 2010 period the empirical results show a 0 38 increase in total factor co2 emission performance as a whole and a u shaped mnmcpi curve for the sample period because companies owned by the central government lack innovation and technological leadership the results suggest a missing link in the role of the central government in promoting co2 emission performance

business cycles in developing countries are they different abstract this paper demonstrates that developing countries differ considerably from their developed counterparts when focus is on the nature and characteristics of short run macroeconomic fluctuations cycles are generally shorter and the stylized facts of business cycles across countries are more diverse than those of the rather uniform industrialized countries supply side models are generally superior in explaining changes in output but a one size fits all approach in formulating policy is inappropriate our results also illustrate the critical importance of understanding business regularities as a stepping stone in the process of designing appropriate stabilization policy and macroeconomic management in developing countries

estimating the environmental efficiency and marginal co2 abatement cost of coal fired power plants in china abstract we estimate the environmental efficiency reduction potential and marginal abatement cost of carbon dioxide co2 emissions from coal fired power plants in china using a novel plant level dataset derived from the first and second waves of the national economic survey which were implemented in 2004 and 2008 respectively the results indicate that there are large opportunities for co2 emissions reduction in china s coal fired power plants given that all power plants operate fully efficiently china s co2 emissions in 2004 and 2008 could have been reduced by 52 and 70 respectively accompanied by an expansion in electricity output in other words the opportunities for double dividend exist in 2004 the average marginal abatement cost of co2 emissions for china s power plants was approximately 955 yuan ton whereas in 2008 the cost increased to 1142 yuan ton the empirical analyses show that subsidies from the government can reduce environmental inefficiency but the subsidies significantly increase the shadow price of the power plants older and larger power plants have a lower environmental efficiency and marginal co2 abatement cost the ratio of coal consumption negatively affects the environmental efficiencies of power plants