reduction potentials of energy demand and ghg emissions in china s road transport sector abstract rapid growth of road vehicles private vehicles in particular has resulted in continuing growth in china s oil demand and imports which has been widely accepted as a major factor effecting future oil availability and prices and a major contributor to china s ghg emission increase this paper is intended to analyze the future trends of energy demand and ghg emissions in china s road transport sector and to assess the effectiveness of possible reduction measures a detailed model has been developed to derive a reliable historical trend of energy demand and ghg emissions in china s road transport sector between 2000 and 2005 and to project future trends two scenarios have been designed to describe the future strategies relating to the development of china s road transport sector the business as usual scenario is used as a baseline reference scenario in which the government is assumed to do nothing to influence the long term trends of road transport energy demand the best case scenario is considered to be the most optimized case where a series of available reduction measures such as private vehicle control fuel economy regulation promoting diesel and gas vehicles fuel tax and biofuel promotion are assumed to be implemented energy demand and ghg emissions in china s road transport sector up to 2030 are estimated in these two scenarios the total reduction potentials in the best case scenario and the relative reduction potentials of each measure have been estimated

estimation on oil demand and oil saving potential of china s road transport sector national social science foundation of china 12zd059 ministry of education 10gbj013 national natural science foundation of china 71203186 fundamental research funds for the central universities 2010221051 national science foundation for disting

overlapping expectations and hart s conditions for equilibrium in a securities model hart j econ theory 9 1974 293 311 gave conditions for equilibrium to exist in a securities model where each agent undertakes asset transactions to maximize expected utility of wealth these conditions rule out agents wanting to undertake unbounded balanced transactions to reach a pareto superior allocation given their expectations with mild extra assumptions to make agents unwilling to risk incurring unbounded losses on their portfolios hart s conditions become equivalent to an assumption of overlapping expectations which is comparable to a much weaker form of green s common expectations econometrica 41 1973 1103 1124

fuel taxes an important instrument for climate policy abstract this article shows that fuel taxes serve a very important role for the environment and that we risk a backlash of increased emissions if they are abolished fuel taxes have restrained growth in fuel demand and associated carbon emissions although fuel demand is large and growing our analysis shows that it would have been much higher in the absence of domestic fuel taxes people often assert that fuel demand is inelastic but there is strong research evidence showing the opposite the price elasticity is in fact quite high but only in the long run in the short run it may be quite inelastic which has important implications for policy makers had europe not followed a policy of high fuel taxation but had low us taxes then fuel demand would have been twice as large hypothetical transport demand in the whole oecd area is calculated for various tax scenarios and the results show that fuel taxes are the single most powerful climate policy instrument implemented to date yet this fact is not usually given due attention in the debate

uniqueness of equilibrium in the classical capital asset pricing model general equilibrium in the classical two period mean variance capital asset pricing model is not unique corresponding to one single set of expectations utility functions and an initial wealth distribution there may be several equilibria and an asset may have different prices expected rates of return and betas in different equilibria however any equilib rium portfolio is sustained by a unique price system and if investors have decreasing risk aversion then any equilibrium allocation ofthe risky assets is sustained by a unique price system tion of the market portfolio of risky assets the other is the simple linear pricing relation expressed in terms of betas and rates of return by sharpe 1964 and in terms of prices by lintner 1965 these properties of equilibrium imply severe restrictions on the possible equilibrium portfolios and equilibrium asset prices and they have led to a presumption that the equilibrium in this model is unique see e g sharpe 1970 relying on mossin s 1966 interpretation ofthe model this paper shows that general equilibrium in the classical capm is not necessar ily unique there may be several equilibria even with the same expected total returns covariances utility functions and initial distribution ofthe assets an asset may have different prices expected rates of return and betas in different equilibria however if just one investor s equilibrium holdings of both the risk less and the risky assets are given then the price system is unique if investors have decreasing risk aversion then the price system is unique given the equilib rium allocation of the risky assets on the other hand if investors do not have decreasing risk aversion then an allocation of risky assets may be sustained by several different price systems

world transport energy demand modelling methodology and elasticities abstract this paper presents the international energy agency s iea approach of modelling transport energy demand fuel demand which is not a demand per se is derived whenever possible from the economic activity in the transport sector and not estimated directly ie using one equation or simultaneous equation system in general the transport models employ a two step approach in the first step transport activity the sector s relevant energy service is estimated econometrically in the second step the transport activity projections are then combined with estimates of efficiency improvements car turnover rates and diesel gasoline penetration assumptions in order to arrive at projections of fuel demand the principal advantages of this approach are that the relevant energy services are modelled and that for model simulation efficiency improvements can be dealt with explicitly the effectiveness of economic instruments is a function of the reaction of consumers and businesses to income and price changes an in depth understanding of income and price elasticities of transport demand and transport energy demand is important in order to be able to assess the effectiveness of policies considered the paper also shows the underlying long term income and price elasticities for oecd and non oecd regions

do lower yielding farmers benefit from bt corn evidence from instrumental variable quantile regressions abstract there have been serious questions about whether lower yielding farmers in developing countries who are typically poor smallholders benefit from genetically modified crops like bacillus thuringensis bt corn this article examines this issue by estimating the heterogeneous impacts of bt corn adoption at different points of the yield distribution using farm level survey data from the philippines a recently developed estimation technique called instrumental variable quantile regression ivqr is used to assess the heterogeneous yield effects of bt corn adoption and at the same time address potential selection bias that usually plague impact assessment of agricultural technologies we find that the positive yield impact of bt corn in the philippines tend to be more strongly felt by farmers at the lower end of the yield distribution this result suggests that bt corn could be a pro poor technology since most of the lower yielding farmers in the philippines are poor smallholders with low incomes

surplus distribution from the introduction of a biotechnology innovation we examine the distribution of welfare from the introduction of bt cotton in the united states in 1996 the welfare framework explicitly recognizes that research protected by intellectual property rights generates monopoly profits and makes it possible to partition these rents among consumers farmers and the innovating input firms we calculate a total increase in world surplus of 240 3 million for 1996 of this total the largest share 59 went to u s farmers the gene developer monsanto received the next largest share 21 followed by u s consumers 9 the rest of the world 6 and the germplasm supplier delta and pine land company 5

car buyers and fuel economy abstract this research is designed to help researchers and policy makers ground their work in the reality of how us consumers are thinking and behaving with respect to automotive fuel economy our data are from semi structured interviews with 57 households across nine lifestyle sectors we found no household that analyzed their fuel costs in a systematic way in their automobile or gasoline purchases almost none of these households track gasoline costs over time or consider them explicitly in household budgets these households may know the cost of their last tank of gasoline and the unit price of gasoline on that day but this accurate information is rapidly forgotten and replaced by typical information one effect of this lack of knowledge and information is that when consumers buy a vehicle they do not have the basic building blocks of knowledge assumed by the model of economically rational decision making and they make large errors estimating gasoline costs and savings over time moreover we find that consumer value for fuel economy is not only about private cost savings fuel economy can be a symbolic value as well for example among drivers who view resource conservation or thrift as important values to communicate consumers also assign non monetary meaning to fuel prices for example seeing rising prices as evidence of conspiracy this research suggests that consumer responses to fuel economy technology and changes in fuel prices are more complex than economic assumptions suggest the us department of energy and the energy foundation supported this research the authors are solely responsible for the content and conclusions presented

equilibrium with investors using a diversity of deviation measures abstract it has been argued that investors who optimize their portfolios with attention paid only to mean and standard deviation will all end up choosing some multiple of a certain master fund portfolio justification for the capital asset pricing model of classical portfolio theory which relates individual assets to such a master fund has come from this direction in particular attempts have been made to provide solid mathematical support by showing that the imputed behavior of investors is a consequence of price equilibrium in a market in which assets are traded subject to budget constraints and optimization is carried out with respect to utility functions that depend only on mean and standard deviation in recent years reliance on standard deviation has come under increasing criticism because of inconsistencies in its effect on portfolio preferences one response has been to introduce generalized measures of deviation which lead to alternative master funds the market implications of such extensions of theory have hitherto been unclear but in this paper the existence of equilibrium is established in circumstances where nonstandard deviations are admitted equilibrium is guaranteed even when different investors use different measures of deviation and thereby end up with portfolios scaled from different master funds whether they employ the same measure or not they may impose caps on deviation which likewise may be different

arbitrage and the existence of competitive equilibrium a general equilibrium model of markets for commodities and assets is considered the author develops the notion of a price system that admits no arbitrage opportunity and demonstrates the fundamenta l role of this concept for the theory of the existence of a competiti ve equilibrium a price system admits no arbitrage opportunity for a consumer if every bundle of desired commodities has a positive market value the author proves that the existence of a price system that a dmits no arbitrage opportunity for all consumers is sufficient for th e existence of an equilibrium copyright 1987 by the econometric society

a critical review of iea s oil demand forecast for china abstract china has a rapidly growing economy with a rapidly increasing demand for oil the international energy agency iea investigated possible future oil demand scenarios for china in the 2006 world energy outlook the debate on whether oil supplies will be constrained in the near future because of limited new discoveries raises the concern that the oil industry may not be able to produce sufficient oil to meet this demand this paper examines the historical relationship between economic growth and oil consumption in a number of countries logistic curve characteristics are observed in the relationship between per capita economic activity and oil consumption this research has determined that the minimum statistical lower bound annual oil consumption for developed countries is 11 barrels per capita despite the increase reported in total energy efficiency no developed country has been able to reduce oil consumption below this lower limit indeed the iea projections to 2030 for the oecd countries show no reduction in oil demand on a per capita basis if this lower limit is applied to china it is clear that the iea projections for china are under estimating the growth in demand for oil this research has determined that this under estimation could be as high as 10 million barrels per day by 2025 if proponents of peak oil such as laherrere campbell and deffeyes are correct about the predicted peak in oil production before 2020 then the implications of this reassessment of china s oil demand will have profound implications for mankind

comparative statics under uncertainty the case of mean variance preferences we analyze the comparative statics of optimal decisions under uncertainty when preferences are represented by twomoment mean variance utility functions we relate our findings to concepts for risk attitudes that are familiar from the expected utility approach in the two parameter approach a number of plausible comparative static effects already emerges under the assumption of decreasing absolute risk aversion to determine comparative static effects of changes in background risks stronger concepts are needed risk vulnerability temperance and standardness imply appropriately transferred to the mean variance framework the plausible effect that risk taking will be reduced if background risks increase 2002 elsevier b v all rights reserved

determinants of china s energy imports an empirical analysis sustained economic growth in china has triggered a surge of energy imports especially oil imports this paper investigates the determinants of china s energy import demand by using cointegraiton and vecm techniques the findings suggest that in the long run growth of industrial production and expansion of transport sectors affect china s oil imports while domestic energy output has a substitution effect thus as the chinese economy industrializes and the automotive sector expands china s oil imports are likely to increase though china s domestic oil production has a substitution effect on imports its growth is limited due to scarce domestic reserve and high exploration costs it is anticipated that china will be more dependent on overseas oil supply regardless of the world oil price

stochastic equilibria with incomplete financial markets abstract we demonstrate the existence of equilibria with incomplete financial markets for stochastic economies whose information structure is given by an event tree restricting attention to purely financial securities those paying in units of account e g dollars financial markets may be incomplete some consumption streams may be impossible to obtain by any trading strategy securities may be individually precluded from trade at arbitrary states and dates sufficient conditions for the existence of stochastic equilibria are continuous convex strictly monotonic preferences and strictly positive aggregate endowments these conditions are weakened a corollary states that any regime of security prices precluding arbitrage can be embedded in an equilibrium

market demand functions in the capital asset pricing model abstract we demonstrate that in a capm economy homogeneity walras law and the tobin separation property characterize market demand on finite sets of prices consequently for any number n there exist capm economies which have at least n equilibria and hence have n different beta pricing formulas endowment perturbations in these economies cannot decrease the number of equilibria below n journal of economic literature classification numbers c62 d51 d52 g12

equilibrium in economies with incomplete financial markets abstract this paper analyses an exchange economy in the absence of arrow debreu complete markets it is assumed that trading takes place in the sequence of spot markets and futures markets for securities payable in units of account unlimited short selling in securities is allowed a general equilibrium in such an economy is a set of current and future prices contingent on uncertain events and a set of individual plans such that all markets are cleared the existence of such an equilibrium is proved under usual assumptions this is in contrast to the case of futures markets for contingent futures commodities where an equilibrium may not exist the optimality of equilibrium allocations is also discussed

bt cotton in india field trial results and economic projections abstract the performance of bt cotton in india is analyzed on the basis of field trial data from 2001 the amounts of pesticides applied during the trials were reduced to one third of what was used in conventional cotton while under severe pest pressure yield gains were 80 productivity effects are modeled econometrically with a damage control specification the first approval for the commercial cultivation of bt hybrids was given in 2002 by 2005 the technology is expected to cover one quarter of total indian cotton area medium term projections show sizeable welfare gains for the overall economy with farmers being the main beneficiaries

mean variance vulnerability this paper transfers the concept of gollier and pratt s gollier c j w pratt 1996 risk vulnerability and the tempering effect of background risk econometrica64 1109 1123 risk vulnerability into mean variance preferences risk vulnerability is shown to be equivalent to the slope of the mean variance indifference curve being decreasing in mean and increasing in variance next we introduce the notion of mean variance vulnerability to link the concepts of decreasing absolute risk aversion risk vulnerability properness and standardness all of the abovementioned concepts are characterized in terms of mean variance indifference curve properties and in terms of absolute risk measures

production risk pesticide use and gm crop technology in south africa technology involving genetic modification of crops has the potential to make a contribution to rural poverty reduction in many developing countries thus far pesticide producing bacillus thuringensis bt varieties of cotton have been the main gm crops under cultivation in developing nations several studies have evaluated the farm level performance of bt varieties in comparison to conventional ones by estimating production technology and have mostly found bt technology to be very successful in raising output and or reducing pesticide input however the production risk properties of this technology have not been studied although they are likely to be important to risk averse smallholders this study investigates the output risk aspects of bt technology by estimating two flexible risk production function models allowing technology to independently affect the mean and higher moments of output the first is the popular just pope model and the second is a more general damage control flexible risk mode

oil palm adoption household welfare and nutrition among smallholder farmers in indonesia summary oil palm is one of the most rapidly expanding crops throughout the humid tropics in indonesia the expansion is largely driven by smallholder farmers while recent research has studied effects for the environment and climate change socioeconomic impacts in the small farm sector have hardly been analyzed here we address this research gap by analyzing effects of oil palm adoption on farm household living standards and nutrition in sumatra using survey data and econometric models we estimate average impacts impact pathways and impact heterogeneity results show that oil palm adoption improves household living standards and nutrition mean impacts on food and non food expenditures as well as on calorie consumption and dietary quality are all positive and significant a sizeable part of the total effects is attributable to oil palm adopters expanding their farm size rather than realizing higher profits per hectare oil palm has lower labor requirements than alternative crops especially rubber so that adopting farmers are able to manage larger land areas labor saved through switching from rubber to oil palm is also used to increase off farm incomes impact heterogeneity is analyzed with quantile regressions we find positive effects of oil palm adoption across the entire expenditure distribution however the absolute gains in total expenditures and non food expenditures are larger for the better off suggesting that oil palm may contribute to rising inequality

positive prices in capm some equilibrium prices in capm may be negative because of nonmonotonicity of preferences we identify several sets of sufficient conditions for prices to be positive the central conditions impose bounds on the investors risk aversion these bounds do not need to hold globally but only in a relevant range of portfolios or combinations of mean and standard deviation the relevant range is specified on the basis of exogenous parameters and variables and it must contain any endogenously determined equilibrium the bounds on risk aversion ensure that the preferences for assets are sufficiently well behaved within the relevant range the two period mean variance capital asset pricing model capm has the peculiar property that preferences may not be monotone the expected return to an investor s portfolio increases as he holds more and more shares of the assets but so does the variance of return it may be that at some point the additional expected return gained from adding more shares to the portfolio is not sufficient to compensate for the increase in variance if so then the induced preferences for assets are not monotone nonmonotonicity of preferences in the mean variance model is analyzed in nielsen 1987 because portfolio preferences are not necessarily monotone equilibrium asset prices may be negative or zero in fact it is possible that the value of the market portfolio of risky assets is negative this is demonstrated in nielsen 1985 1990a and in two examples in the present paper when the capm is used as a model of the prices of stocks which in reality have limited liability it is of course disturbing that it may predict negative prices it can be seen as a symptom of the fact that mean variance preferences are not always a good approximation to reality this paper analyzes various conditions on the exogenous parameters which ensure that the preferences are sufficiently realistic to yield positive prices the exogenous parameters in question are the expectations variances and covariances of total returns the initial allocations of the assets endowments and the investors utility functions for mean and variance of return the analysis applies to the classical version of the capm with a riskless asset as developed by sharpe 1964 lintner 1965 and mossin 1966 as well as the capm with risky assets only which was introduced by black 1972 and has been much used in empirical work under the name the zero beta or two factor capm

the rebound effect some empirical evidence from india abstract the present paper looks at the effect of technical efficiency gains on energy use in three sectors in india at varying levels of aggregation high positive rebound implies that efficient technology unless supplemented by appropriate pricing policy will not be successful in containing demand however the main purpose of the paper is to focus on the unique mechanism of rebound that may occur in developing countries with unmet demand

necessary conditions for the capm abstract the general restrictions on all economic primitives i e a endowments b preferences and c asset return distributions that yield the capm under the expected utility paradigm are provided these results are then used to derive the class of restrictions on preferences and the distribution of asset returns alone that provides the capm we also show that the conditions that provide the capm and derived preferences over mean and variance are equivalent consequently this paper also resolves the question of when mean variance maximization is consistent with expected utility maximization journal of economic literatureclassification numbers g12 g11 d50

the effects of 401 k participation on the wealth distribution an instrumental quantile regression analysis we use instrumental quantile regression approach to examine the effects of 401 k plans on wealth using data from the survey of income and program participation using 401 k eligibility as an inst

existence of equilibrium in capm abstract in the mean variance capital asset pricing model capm non monotonicity of preferences may lead to satiation and short selling as well as satiation may lead to non existence of equilibrium this paper identifies several sets of sufficient conditions for equilibrium to exist the nature of the central conditions is to impose bounds on the investors degree of risk aversion as measured by the marginal rate of substitution between mean and standard deviation of return these bounds do not need to hold globally but only in a relevant range of portfolios or combinations of mean and standard deviation