discount rates equity weights and the social cost of carbon abstract equity weighting has been proposed as a way of allowing welfare equivalents to be included in the social cost of carbon since a dollar to a poor person is worth more than a dollar to a rich one here we use the page2002 integrated assessment model to show that the social cost of carbon is higher without equity weights an elasticity of marginal utility with respect to income of 0 than with them this might seem counter intuitive but it comes about because of the logical link between equity weights and discount rates as the elasticity goes from 0 to 0 5 to 1 0 the social rate of time preference rises and the drop in present values that results far outweighs the small increase in impacts that equity weights bring

unequal vulnerability to climate change and the transmission of adverse effects through international trade in this paper we consider the unequal distribution of climate change damages in the world and we examine how the underlying costs can spread from a vulnerable to a non vulnerable country through international trade to focus on such indirect effects we treat this topic in a north south trade overlapping generations model in which the south is vulnerable to the damages entailed by global pollution while the north is not we show that the impact of climate change in the south can be a source of welfare loss for northern consumers in both the short and the long run in the long run an increase in the south s vulnerability can reduce the welfare in the north economy even in the case in which it improves its terms of trade in the short run the south s vulnerability can also represent a source of intergenerational inequity in the north therefore we emphasize the strong economic incentives for non vulnerable and a fortiori less vulnerable economies to reduce the climate change damages on more vulnerable countries

frontiers of climate change economics the economics of climate change is an active field of research the contributions to a special issue are put in context of the literature and it is suggested that second best issues such as carbon leakage and the green paradox need to be complemented with a political economy analysis of why certain instruments are politically infeasible and with intra and intergenerational analyses of the impact of climate policy a case is also made for more empirical work on the gradual and catastrophic damages of global warming

global warming and hyperbolic discounting the use of a constant discount rate to study long lived environmental problems such as global warming has two disadvantages the prescribed policy is sensitive to the discount rate and with moderate discount rates large future damages have almost no effect on current decisions time consistent quasi hyperbolic discounting alleviates both of these modeling problems and is a plausible description of how people think about the future we analyze the time consistent markov perfect equilibrium in a general model with a stock pollutant the solution to the linear quadratic specialization illustrates the role of hyperbolic discounting in a model of global warming

pricing carbon and adjusting capital to fend off climate catastrophes the optimal reaction to a potential productivity shock as a consequence of climate tipping is to substantially tax carbon in order to curb the risk of tipping but to adjust capital as well in order to smooth consumption when tipping occurs we also allow for conventional marginal climate damages and decompose the optimal carbon tax in two catastrophe components and the conventional component we distinguish constant and increasing marginal hazards moreover the productivity catastrophe is compared with recoverable catastrophes and with a shock to the climate sensitivity finally we allow for investments in adaptation capital as an alternative to counter the potential adverse effects of climate tipping quantitatively the results are investigated with a calibrated model for the world economy

limit pricing and the in effectiveness of the carbon tax we present a theory of limit pricing monopoly in non renewable resource production facing a very inelastic demand an oil monopoly seeks to induce the highest price that does not destroy its demand unlike the conventional hotellian analysis the monopoly tolerates some ordinary substitutes to its oil but deters high potential ones with limit pricing policy induced extraction changes do not obey the usual logic for example oil taxes have no effect on current oil production extraction increases when high potential substitutes are promoted but can be effectively reduced by supporting ordinary substitutes the carbon tax not only applies to oil it also penalizes its ordinary carbon substitutes whose market shares are taken over by the monopoly thus the carbon tax ambiguously affects current and long term oil production and carbon emissions

tipping points and business as usual in a global commons abstract this paper analyzes a dynamic strategic model of resource extraction from a global commons countries derive benefits from both direct extraction and aggregate conservation of an open access resource each period a country s output depends both on its resource usage and on the global stock of the resource stored within the ecosystem leading examples are ocean fisheries habitat preservation forestry and land carbon biomass the production coefficients on these inputs vary across countries and evolve stochastically over time a business as usual bau equilibrium characterizes each country s resource usage in the absence of an effective international agreement under non concave resource dynamics depletion of the resource in a bau equilibrium may reach a tipping point below which the stock spirals downward toward a steady state of marginal sustainability under the assumptions of the model the tipping points emerge endogenously if the number of extractors exceeds some fixed finite bound the commons always tips regardless of the initial stock we find that countries will accelerate their rates of extraction the closer they are to reaching the low end steady state by contrast in the socially efficient plan the commons never tips if the initial stock is large

taxing fossil fuels under speculative storage long term environmental consequences of taxing fossil fuel usage have been extensively studied in the literature however these taxes may also impose several short run macroeconomic policy challenges the nature of which remains underexplored this paper investigates the mechanisms through which environmental taxes on fossil fuel usage can affect the main macroeconomic variables in the short run we concentrate on a particular mechanism speculative storage formulating and using a dynamic stochastic general equilibrium dsge model calibrated for the united states with an explicit storage facility and nominal rigidities we show that in designing environmental tax policies it is crucial to account for the fact that fossil fuel prices are subject to speculation the existence of forward looking speculators in the model improves the effectiveness of tax policies in reducing fossil fuel usage improved policy effectiveness however is costly it drives inflation and interest rates up while impeding output based on this tradeoff we seek an answer to the question how monetary policy should interact with environmental tax policies in our dsge model of fossil fuel storage we show that in an environment with no speculative storers monetary policy should respond to output along with cpi inflation in order to minimize the welfare losses brought by taxes however when the storage facility is activated responding to output in the monetary policy rule becomes less desirable

directed technical change with capital embodied technologies implications for climate policy abstract we develop a theoretical model of directed technical change in which clean zero emissions and dirty emissions intensive technologies are embodied in long lived capital stocks switching from dirty to clean innovation leads to ongoing reductions in the relative costs of producing clean investment goods making them ever cheaper to purchase and so encouraging clean investment at the same time falling replacement costs imply falling asset values consequently continuing innovation in capital embodied clean technologies also generates obsolescence costs which are borne by users of clean capital the negative effect of obsolescence costs on demand for clean investment and consequently on the speed of transition to clean growth has been neglected in the literature on directed technical change we show theoretically and using numerical simulations that optimal policies differ in our model of embodied technological change relative to an otherwise comparable model of disembodied technological change with embodied technologies i optimal emissions taxes start higher and rise faster ii much higher clean research and development subsidies are required to effect the switch to clean innovation and iii climate damages under optimal policies are greater we suggest that more attention should be paid to the role of obsolescence costs in modelling transitional effects of climate policies

robustness of a simple rule for the social cost of carbon abstract the optimal social cost of carbon is in general equilibrium proportional to gdp if utility is logarithmic production is cobb douglas depreciation is 100 every period climate damages as fraction of production decline exponentially with the stock of atmospheric carbon and fossil fuel extraction does not require capital the time profile and size of the optimal carbon tax corresponding to this simple rule are not robust to more convex climate damages smaller elasticities of factor substitution and non unitary coefficients of relative intergenerational inequality aversion the optimal timing of energy transitions and the amount of fossil fuel reserves to be locked up in the earth are also not accurately predicted by this framework still in terms of welfare and global warming the simple rule for the optimal social cost of carbon manages to get quite close to the first best

energy balance climate models and general equilibrium optimal mitigation policies in a general equilibrium model of the world economy we develop a two dimensional energy balance climate model featuring heat diffusion and anthropogenic forcing driven by global fossil fuel use across the sphere of the earth this introduces an endogenous location dependent temperature function driving spatial characteristics in terms of location dependent damages resulting from local temperature anomalies into the standard climate economy framework we solve the social planner s problem and characterize the competitive equilibrium for two polar cases differentiated by the degree of market integration we define optimal taxes on fossil fuel use and how they may implement the planning solution our results suggest that if the implementation of international transfers across latitudes is not possible then optimal taxes are in general spatially non homogeneous and may be lower at poorer latitudes the degree of spatial differentiation of optimal taxes depends on heat transportation by employing the properties of the spatial model we show by numerical simulations how the impact of thermal transport across latitudes on welfare can be studied

the social economic and environmental implications of biomass ethanol production in china a multi regional input output based hybrid lca model abstract as an alternative to conventional liquid fuels bioethanol holds the promise of transitioning to a clean and low carbon energy future china s bioethanol industry is at its nascent stage in this study we developed a hybrid life cycle assessment model that integrates the multi regional input output mrio approach and specific production data to evaluate the social economic and environmental i e the triple bottom line tbl impacts of the bioethanol sector in china s economic systems the mrio model was constructed using the 2012 mrio table and the data for the typical technologies of bioethanol production were leveraged to be specific we evaluated employment creation economic stimulus and energy use of bioethanol production in 28 scenarios in henan province the results show that compared to petroleum refining bioethanol production is more effective for economic stimulus and energy saving but less effective at job creation the impact of bioethanol production varies by technologies for every 1 million yuan of bioethanol production in china economic system first generation technology offers a projected 1 92 million yuan in economic growth and job creation of 2 06 full time equivalent while the second generation technology offers a lower energy consumption 1 19 tj in most scenarios the upstream sectors account for more than half of the tbl impacts of biofuel production this study helps to quantify the tbl impacts associated with the gasoline to bioethanol transition in china envisions the green opportunities for impact mitigation and sheds light on the potential direction for robust planning and policy making to advance the bioethanol industry s development

climatic tipping points and optimal fossil fuel use the economics of climate change is characterized by many uncertainties regarding for instance climate dynamics economic damages and potentially irreversible climate catastrophes using an optimal growth model of a fossil fuel driven economy subject to climate externalities and potentially irreversible climatic regime shifts this paper contributes to the understanding of how the risk of such events impacts on optimal fossil fuel use carbon taxes and fossil fuel prices over time we show that in excess to an increase in the expected present value of marginal damages and an increase in the probability of triggering the event there also exists a third opposing effect this effect comes from the fall in value of remaining fossil fuel reserve which results from the potential regime shift which may or may not occur sometime in the future and implies that optimal fossil fuel policy shifts towards using more resources early on this effect is related to the idea of the green paradox we prove the existence of this effect and show under which circumstances it can become quantitatively important numerically the green paradox effect seems to be somewhat smaller than but comparable in size to the increase in expected marginal damages in general our findings highlight the importance of considering the supply side impacts on climate policy in response to catastrophic climate events

intertemporal distribution sufficiency and the social cost of carbon abstract we explore how the intertemporal distribution of well being affects the social cost of carbon in contrast to the literature that studies parameters of a particular social welfare function such as the discount rate we shift the focus and directly assume a parametric form for the intertemporal distribution of well being this has the advantage of avoiding explicit discounting choices which has initiated much debate specifically we consider a set of intertemporal distributions that reach a steady state at a pre specified level of sufficient well being or equivalently after a pre specified end of growth horizon we numerically illustrate our results in dice and find that the social cost of carbon increases over proportionally with the sufficiency level of well being while the social cost of carbon in 2015 is us 7 if the sufficiency level is four fold the present level it is us 30 if the sufficiency level is 15 fold and us 100 if the sufficiency level is 26 fold the present level this shows in a transparent way how conceptions of intergenerational distributive justice drive the social cost of carbon

the supply of non renewable resources there exists no formal treatment of non renewable resource nrr supply systematically deriving quantity as function of price we establish instantaneous restricted fixed reserves and unrestricted nrr supply functions the supply of a nrr at any date and location not only depends on the local contemporary price of the resource but also on prices at all other dates and locations besides the usual law of supply which characterizes the own price effect cross price effects have their own law they can be decomposed into a substitution effect and a stock compensation effect we show that the substitution effect always dominates a price increase at some point in space and time causes nrr supply to decrease at all other points this new but orthodox supply setting extends to nrrs the partial equilibrium analysis of demand and supply policies thereby it provides a generalization of many results about policy induced changes on nrr markets the properties of restricted and unrestricted supply functions are characterized for hotelling homogeneous as well as ricardian non homogeneous reserves for a single deposit as well as for several deposits that endogenously come into production or cease to be active

carbon pricing carbon sequestration and social discounting abstract this paper studies the optimal taxation of carbon emissions in a dynastic economy when the welfare function places direct pareto weights on unborn generations the social discount rate is lower than the discount rate of the current generation i show that this welfare criterion has important consequences for the structure of the optimal regulatory system in particular i show that i the optimal carbon tax does not in general equal the social cost of carbon ii a subsidy on oil reserves is sometimes optimal and iii carbon trading programs should limit the award of carbon offset allowances

modeling the demand for narrow money in the united kingdom and the united states abstract despite the importance of well specified empirical money demand functions for inference forecasting and policy problems in modeling have arisen concerning the economic theories of money demand the data institutional frameworks financial innovation and econometric implementation by developing constant data coherent m 1 demand equations for the u k and the u s we investigate these issues and explain such puzzles as missing money the great velocity decline and the recent explosion in m 1 the endogeneity of money the lucas critique and the non invertibility of our m 1 models are also discussed

economic growth effects of alternative climate change impact channels in economic modeling despite increasing empirical evidence of strong links between climate and economic growth there is no established model to describe the dynamics of how different types of climate shocks affect growth patterns here we present the first comprehensive comparative analysis of the long term dynamics of one time temporary climate shocks on production factors and factor productivity respectively in a ramsey type growth model damages acting directly on production factors allow us to study dynamic effects on factor allocation savings and economic growth we find that the persistence of impacts on economic activity is smallest for climate shocks directly impacting output and successively increases for direct damages on capital loss of labor and productivity shocks related to different responses in savings rates and factor specific growth recurring shocks lead to large welfare effects and long term growth effects directly linked to the persistence of individual shocks endogenous savings and shock anticipation both have adaptive effects but do not eliminate differences between impact channels or significantly lower the dissipation time accounting for endogenous growth mechanisms increases the effects we also find strong effects on income shares important for distributional implications this work fosters conceptual understanding of impact dynamics in growth models opening options for links to empirics

carbon footprint scenarios for renewable electricity in australia abstract despite considerable mitigation efforts global emissions from the electricity sector continued to grow in recent years in australia the electricity sector is the largest co 2 emitting industry contributing 35 of the country s total greenhouse gas emissions the australian government targets an 80 reduction of greenhouse gas emissions by 2050 relative to 2010 with a large variety and quantity of renewable energy resources it is technically feasible and seems indispensable that australia s electricity sector be largely decarbonised by 2050 in order to achieve this target in this paper scenario based hybrid life cycle assessment is applied to calculate the economy wide carbon footprints of seven electricity generation technologies in scenarios with differing renewable electricity penetration this work is the first to apply a full life cycle approach to scenario analysis of electricity generation in australia the findings are at the higher end of previously reported carbon footprint intensity ranges and above median values however even when taking into account indirect emissions along the technologies life cycles the results indicate that the employment of different renewable energy technologies can potentially save a considerable fraction of australia s greenhouse gas emissions this makes renewables an essential option for climate change mitigation

environmental taxation employment and public spending in developing countries this paper investigates the consequences of environmental tax reforms for unemployment and welfare in the case of developing countries with a large informal sector rural urban migration and three different assumptions about public spending 1 as part of a revenue neutral policy 2 fixed and 3 varying endogenously under the indexation of unemployment benefits and informal sector income that give rise to a double dividend a lower level of public spending is associated with a smaller negative impact on the after tax income of households and a higher increase in employment these policies however still lead to a reduction in social welfare even more so in the case of endogenous public spending although it is associated with a higher increase in employment and a smaller reduction in private sector incomes the model implies that complementary policy in terms of lower public spending is unlikely to be socially acceptable and does not support the case for a green tax reforms in developing countries

substitution between clean and dirty energy inputs a macroeconomic perspective in macroeconomic models the elasticity of substitution between clean and dirty energy inputs within the energy aggregate is a central parameter in assessing the necessary conditions for long run green growth using new sectoral data in a panel of 26 countries we formulate specifications of nested constant elasticity of substitution production functions that allow estimating this parameter for the first time we present evidence that it significantly exceeds unity a favorable condition for promoting green growth

interfuel substitution a meta analysis interfuel substitutability has been of longstanding interest to the energy economics and policy community however no quantitative meta analysis has yet been carried out of this literature this paper fills this gap by analyzing a broad sample of studies of interfuel substitution in the industrial sector manufacturing industry or subindustries or macro economy of a variety of developed and developing economies publication bias is controlled for by including the primary study sample size in the meta regression results for the shadow elasticities of substitution between coal oil gas and electricity for forty six primary studies show that at the level of the industrial sector there are easy substitution possibilities between all the fuel pairs with the exception of gas electricity and coal electricity substitution possibilities seem more constrained at the macro level and less constrained in sub industries estimates also vary across countries publication bias does not seem to be present but model and data specification issues very significantly affect the estimates derived by each individual study estimates from cross section regressions are generally largest fixed effects panel estimates intermediate in magnitude and time series estimates are mostly much smaller econometric research suggests that the fixed effects estimates are likely the best among the existing studies though biased downwards

the demand for m1 in the united states a comment on baba hendry and starr a recent paper by y baba d hendry and r starr 1992 presents an error correction model of the demand for m1 in the united states which shows a dramatic improvement in both fit and stability over earlier models this note estimates an alternative model with the same data set and draws two conclusions that the improvements are due more to the use of complex dynamics than to the introduction of variables representing financial innovation and that some of the economic properties are not robust with respect to minor changes in specification copyright 1993 by royal economic society

the impact of global warming on agriculture a ricardian analysis reply we measure the economic impact of climate on land prices using cross sectional data on climate farmland prices and other economic and geophysical data for almost 3 000 counties in the united states we find that higher temperatures in all seasons except autumn reduce average farm values while more precipitation outside of autumn increases farm values applying the model to a global warming scenario shows a significantly lower estimated impact of global warming on u s agriculture than the traditional production function approach and in one case suggests that even without co sub 2 fertilization global warming may have economic benefits for agriculture 16 refs 5 figs 5 tabs

the search for a stable money demand function a survey of the post 1973 literature phe question of whether the demnand function for money is stable is one of the most important recurring issues in the theory and application of macroeconomic policy what is being sought in a stable demand function is a set of necessary conditions for money to exert a predictable influence on the economy so that the central bank s control of the money supply can be a useful instrument of economic policy as such the notion of a stable demand function appears to involve three key elements e g john t boorman 1976 p 317 and david e w laidler 1977 pp 34 35 first the demand for money relation should be highly predictable in a statistical sense as measured by the usual goodness of fit statistics precision of estimated coefficients and presumably its ability to forecast accurately out of sample second a stable demand function for money has relatively few arguments a relationship that requires knowledge about a large number of variables in order to pin it down is in effect not predictable finally the variables that appear as arguments in the function should represent significant links to spending and economic activity in the real sector in sum a stable demand function for money means that the quantity of money is predictably related to a small set of key variables linking money to the real sector of the economy the importance of a stable money demand function for monetary policy can be illustrated with the standard is lm model in which interest rates and gnp are the endogenous variables in this context a stable demand function for money translates into a well defined relationship between money interest rates and gnp

the demand for m1 in the united states a reply to james m boughton using general to simple methods j m boughton 1993 develops an econometric model that fits almost as well as y baba d f hendry and r m starr bhs 1992 but differs in economic implications and dynamic adjustments he claims the new model is constant is not encompassed by bhs but does not encompass bhs he concludes that the new variables in bhs do not matter for fit or constancy the authors replicate boughton s findings but their simplification encompassing test confirms the importance of the novel variables in bhs and shows that bhs encompasses his model an explanation is offered for its constancy when previous studies suffered predictive failure

fossil fuel producers under threat oil and gas producers face three threats prolonged low oil and gas prices tightening of climate policy and a tough budget on cumulative carbon emissions and technological innovation producing cheap substitutes for oil and gas these threats pose real risks of putting oil and gas producers out of business they lead to the problem of stranded assets and a significant downward valuation of oil and gas producers this calls for divesting from and shorting coal oil and gas the economies of oil and gas rich countries are typically in a deplorable state since they did not use their past windfalls to build up buffers and invest in a diversified economy more rapacious depletion of their oil and gas reserves will not help after the crash in oil and gas prices these countries are facing serious problems and it is difficult to see how they will cope with the outlined threats

reinterpreting the dhsy 1978 consumption function with hindsight the justification for davidson hendry srba and yeo s dhsy s selection of their favoured equation is shown to be based upon contradicting assumptions about inflation the empirically supported model is argued not to have a theoretically justified error correction interpretation the exclusion of the intercept biases the error correction term such that it becomes significant and negative but undermines the theoretical plausibility of the long run target more generally the statistical need to include an intercept in any regression to avoid parameter bias is demonstrated the rise in inflation in the 1970s is not considered to be a credible explanation of the fall in the average propensity to consume apc from the 1950s and is shown to have questionable empirical support when a below unit income elasticity is allowed for the recent articles which have found support for dhsy s favoured formulation augmented by time varying parameters using the most contemporary uk data should be viewed with caution new interpretations for the dhsy model s persistent success are called for if it is not to be considered that dubious regressions have been resurrected

steering the climate system using inertia to lower the cost of policy common views hold that the efficient way to limit warming to a chosen level is to price carbon emissions at a rate that increases exponentially we show that this hotelling tax on carbon emissions is actually inefficient the least cost policy path takes advantage of the climate system s inertia to delay reducing emissions and allow greater cumulative emissions the efficient carbon tax follows an inverse u shaped path and grows more slowly than the hotelling tax economic models that assume exponentially increasing carbon taxes are overestimating the cost of limiting warming overestimating the efficient near term carbon tax and overvaluing technologies that mature sooner

the welfare implications of climate change policy abstract the response to three different climate change policies is measured within a general equilibrium model of world output technological change greenhouse gas emissions and climate driven changes in productivity the proposed policies including an approximation to the kyoto protocol are shown to differ greatly in how they mitigate climate change support economic growth and allocate rents across generations benefits of alternative policies relative to the status quo do not necessarily accrue to the generations that bear the costs the results also show that the chosen rent distribution rule has a profound effect on policy evaluation in particular policies which allocate rents on a per capita basis are shown to be systematically welfare preferred to situations where emissions rights are grandfathered to emitting firms this implies that both the optimal level of emissions and the welfare cost of reaching a given target of emissions or atmospheric concentration would be lower under a per capita allocation of emissions permits or carbon tax revenues

temperature shocks and welfare costs abstract this paper examines the welfare implications of rising temperatures using a standard var we empirically show that a temperature shock has a sizable negative and statistically significant impact on tfp output and labor productivity we rationalize these findings within a production economy featuring long run temperature risk in the model macro aggregates drop in response to a temperature shock consistent with the novel evidence in the data such adverse effects are long lasting over a 50 year horizon a one standard deviation temperature shock lowers both cumulative output and labor productivity growth by 1 4 percentage points based on the model we also show that temperature risk is associated with non negligible welfare costs which amount to 18 4 of the agent s lifetime utility and grow exponentially with the size of the impact of temperature on tfp finally we show that faster adaptation to temperature shocks results in lower welfare costs these welfare benefits become substantially higher in the presence of permanent improvements in the speed of adaptation

abrupt positive feedback and the social cost of carbon optimal climate policy should act in a precautionary fashion to deal with tipping points that occur at some future random moment the optimal carbon tax should include an additional component on top of the conventional present discounted value of marginal global warming damages this component increases with the sensitivity of the hazard to temperature or the stock of atmospheric carbon if the hazard of a catastrophe is constant no correction is needed of the usual pigouvian tax the results are applied to a tipping point resulting from an abrupt and irreversible release of greenhouse gases from the ocean floors and surface of the earth which set in motion a positive feedback loop convex enough hazard functions cause overshooting of the carbon tax but a linear hazard function gives rise to undershooting a more convex hazard function and a high discount rate speed up adjustment

emissions trading systems with cap adjustments abstract emissions trading systems etss with fixed caps lack provisions to address systematic imbalances in the supply and demand of permits due to changes in the state of the regulated economy we propose a mechanism which adjusts the allocation of permits based on the current bank of permits the mechanism spans the spectrum between a pure quantity instrument and a pure price instrument we solve the firms emissions control problem and obtain an explicit dependency between the key policy stringency parameter the adjustment rate and the firms abatement and trading strategies we present an analytical tool for selecting the optimal adjustment rate under both risk neutrality and risk aversion which provides an analytical basis for the regulator s choice of a responsive ets policy

pricing uncertainty induced by climate change geophysicists examine and document the repercussions for the earth s climate induced by alternative emission scenarios and model specifications using simplified approximations they produce tractable characterizations of the associated uncertainty meanwhile economists write highly stylized damage functions to speculate about how climate change alters macroeconomic and growth opportunities how can we assess both climate and emissions impacts as well as uncertainty in the broadest sense in social decision making we provide a framework for answering this question by embracing recent decision theory and tools from asset pricing and we apply this structure with its interacting components to a revealing quantitative illustration

too much coal too little oil abstract our main message is that it is optimal to use less coal and more oil once one takes account of coal being a backstop which emits much more co2 than oil the way of achieving this is to have a steeply rising carbon tax during the initial oil only phase a less steeply rising carbon tax during the intermediate phase where oil and coal are used alongside each other and the following coal only phase and a flat carbon tax during the final renewables only phase the laissez faire outcome uses coal forever or starts with oil until it is no longer cost effective to do so and then switches to coal we also analyze the effects on the optimal transition times and carbon tax of a carbon free albeit expensive backstop solar or wind energy subsidizing renewables to just below the cost of coal does not affect the oil only phase the gain in green welfare dominates the welfare cost of the subsidy if the subsidy gap is small and the global warming challenge is acute without a carbon tax a prohibitive coal tax leads to less oil left in situ and substantially delays introduction of renewables but curbs global warming substantially as coal is never used finally we characterize under general conditions what the optimal sequencing oil and coal looks like

opec unconventional oil and climate change on the importance of the order of extraction we show that opec s market power contributes to climate change by enabling producers of relatively expensive and dirty oil to start producing before opec reserves are depleted we examine the importance of this extraction sequence effect by calibrating and simulating a cartel fringe model of the global oil market while welfare net of climate damage under the cartel fringe equilibrium can be significantly lower than under a first best outcome almost the entire welfare loss is due to the sequence effect of opec s market power in our benchmark calibration the cost of the sequence effect amounts to 15 trillion us which corresponds to 97 percent of the welfare loss moreover we find that an increase in non opec oil reserves decreases global welfare in a counterfactual world without non opec oil global welfare would be 13 trillion us higher 10 trillion us of which is due to lower climate damages

power markets in transition decarbonization energy efficiency and short term demand response abstract energy efficiency and short term demand response are key issues in the decarbonization of power markets however their interaction and combined impact on market prices as well as on the supply side is yet to be understood we develop a framework to implement short term demand response and investments in energy efficiency in detailed partial equilibrium power market models we quantify our results using the eu regen model for the european power market under an 80 emission reduction target energy efficiency contributes only 11 of carbon emission reductions intermittent renewable energies such as wind and solar power account for the major share of 53 in comparison to a scenario without short term demand response and energy efficiency investments 70 gw gas power is decommissioned immediately and 180 gw less gas capacity is needed in 2050 which underlines the need for immediate action by policy makers to avoid locking the eu power market into an inefficient path

uninsured idiosyncratic production risk with borrowing constraints the author analyzes a general equilibrium model of a heterogeneous agents economy in which the agents are subject to borrowing constraints and uninsurable idiosyncratic production risk

simulating the impact of new industries on the economy the case of biorefining in australia abstract we investigate the economic and employment consequences of introducing a new sugarcane based biofuel industry into australia we model the new biofuel industry on the production recipe of the existing large scale gasoalcohol and alcohol sectors in the brazilian economy to this end we utilise a hybrid io lca input output life cycle assessment approach which involves inserting data on new processes and or sectors into an existing io table in particular we develop and test an analytical and a numerical approach for re balancing an io table augmented with rows and columns representing large new biofuel industries we quantify changes in economic output and employment in the australian economy we conclude that a future biofuel industry will be employment positive for australia

consistent climate policies what are the optimal climate policies when time preferences deviate from the standard exponential discounting and decision makers cannot commit to future policies we show that with time declining discounting the delay and persistence of climate impacts provide a commitment device to policy makers we quantify the commitment value in a climate economy model by solving time consistent markov equilibrium capital and emission taxes explicitly the returns on capital and climate investments are no longer equal leading to a large increase in the emission tax compared to a benchmark with equalized returns the commitment value increases the tax by a factor of 20 in our quantitative assessment

income and wealth heterogeneity in the macroeconomy how do movements in the distribution of income and wealth affect the macroeconomy we analyze this question using a calibrated version of the stochastic growth model with partially uninsurable idiosyncratic risk and movements in aggregate productivity our main finding is that in the stationary stochastic equilibrium the behavior of the macroeconomic aggregates can be almost perfectly described using only the mean of the wealth distribution this result is robust to substantial changes in both parameter values and model specification our benchmark model whose only difference from the representative agent framework is the existence of uninsurable idiosyncratic risk displays far less cross sectional dispersion and skewness in wealth than u s data however an extension that relies on a small amount of heterogeneity in thrift does succeed in replicating the key features of the wealth data furthermore this extension features aggregate time series that depart significantly from permanent income behavior

transitional impacts of environmental policy in an endogenous growth model to explore the link between a tighter environmental policy and economic growth the authors employ an endogenous growth model with endogenous technological progress in abatement technologies the environment which is modelled as a renewable resource acts both as a public consumption good and as a public input into production the entire transition towards a new balanced growth path after a tightening of environmental policy is computed analytically the authors find sharp contrasts between short run and long run effects whereas the level and the growth rate of output may decline in the short run income growth may improve in the long run copyright 1996 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

carbon prices for the next hundred years this paper examines the socially optimal pricing of carbon emissions over time when climate change impacts are unknown potentially high consequence events the carbon price tends to increase with income but learning about impacts or their absence decouples the carbon price from income growth the price should grow faster than the economy if the past warming is not substantial enough for learning the true long run social cost it grows slower than the economy as soon as the warming generates information about events that could have arrived but have not done so a quantitative assessment shows that the price grows roughly at the rate of the economy for the next 100 years

optimal taxes on fossil fuel in general equilibrium we analyze a dynamic stochastic general equilibrium dsge model with an externality through climate change from using fossil energy our central result is a simple formula for the marginal externality damage of emissions or equivalently for the optimal carbon tax this formula which holds under quite plausible assumptions reveals that the damage is proportional to current gdp with the proportion depending only on three factors i discounting ii the expected damage elasticity how many percent of the output flow is lost from an extra unit of carbon in the atmosphere and iii the structure of carbon depreciation in the atmosphere thus the stochastic values of future output consumption and the atmospheric co2 concentration as well as the paths of technology whether endogenous or exogenous and population and so on all disappear from the formula we find that the optimal tax should be a bit higher than the median or most well known estimates in the literature we also formulate a parsimonious yet comprehensive and easily solved model allowing us to compute the optimal and market paths for the use of different sources of energy and the corresponding climate change we find coal rather than oil to be the main threat to economic welfare largely due to its abundance we also find that the costs of inaction are particularly sensitive to the assumptions regarding the substitutability of different energy sources and technological progress

to build or not to build capital stocks and climate policy abstract we investigate i the impact of emission reduction policy on investment in polluting infrastructure such as coal fired power stations and ii optimal subsidies for clean alternatives with learning spillovers we build a general theoretical model and embed it in a fully calibrated integrated assessment model because emission reduction policy reduces investments in polluting assets short term emission reductions are enhanced our irreversibility effect thus stranded assets in this fuel using sector have distinctive properties we also provide a simple formula for how the optimal subsidy to deployment of a clean sector depends on its rate of learning by doing and on its socially optimal growth so if the sector should grow faster for other reasons its optimal subsidy is increased showing that its optimal growth rate is faster still our acceleration effect our calibrations show that to limit global climate change to 2 c warming investments in coal fired power stations must end very soon considering second best settings we show that carbon taxes achieve stringent policy targets more efficiently but subsidies to the clean sector deliver higher welfare and are more efficient when policy targets are more mild

microfoundations and the demand for money the reader should note that i write this piece in a style that aims to be accessible to that much neglected representative agent the woman on the eurostar train hence unlike the man on the clapham omnibus i assume my intrepid traveller has reasonable knowledge of monetary economics and econometrics but not of the details of the demand for money space constraints force me to indulge in a certain amount of poetic licence but i hope this results in poetic justice there have been many wars fought on this particular battlefield some with almost religious zeal on the theoretical side of the debate we sometimes have the equivalent of religious fundamentalists be they muslims jews christians etc who would dismiss almost any evidence unless it were associated with a strong microtheoretic basis as laid down in the koran talmud or bible the empirical side encompasses agnostics atheists as well as born again econometricians pure theorists inhabit the sunlit uplands while applied economists and policymakers flounder in the muddy plain below occasionally gaining solace from their copy of zen and the art of motorcycle maintenance in general in economics we do not have the luxury of controlled experiments as is the case in the natural sciences what distinguishes good microfoundations from bad and how to weight priors and statistical evidence is subject to much dispute leamer i983 hendry et al i990 as in religion sometimes there is the occasional miracle proclaimed after a suitable interval a new saint may be declared and disciples flock to the new shrine later doubts may arise as to whether a miracle really did occur human behaviour is difficult to explain let alone predict so the search for the equivalent of the holy grail ark of the covenant etc is bound to be arduous in scholarly journals we generally read of the success of the demand for money like diplomats who are sent abroad to lie for the good of their country publication may require applied economists to be somewhat economical with the actualite lovell i983 leamer i983 in this article i want to be as honest as possible about our success and failures in this area the prior information an armchair economist would consider when thinking about the demand for money over the past 40 years in western industrialised countries which have experienced moderate inflation might

business cycles and emission trading with banking abstract we propose an emission cap adjustment policy for an emission trading system ets that allows banking of allowances for later use and faces business cycle uncertainty the forward looking banking decisions cause a commitment problem with respect to regulator s next period allowance supply decision we tackle the commitment problem by focusing on the markov equilibrium of the policy the equilibrium policy has a surprisingly simple structure combining features from both price and quantity instruments the regulator s ability to choose a new cap for each period does not render banking obsolete but on the contrary makes banking an integral part of the equilibrium policy using data from the eu ets to calibrate the model we solve the markov equilibrium policy for the case of carbon emissions regulation and compare markov policies with and without the possibility to bank allowances a counterfactual analysis of the eu ets during the period of 2009 2013 shows that the optimal markov policy would have led to a steadier allowance price level and a stricter emission regulation than what was actually observed in the eu ets

faraway so close coupled climate and economic dynamics in an agent based integrated assessment model abstract in this work we develop an agent based model that offers an alternative to standard computable general equilibrium integrated assessment models iams the dystopian schumpeter meeting keynes dsk model is composed of heterogeneous firms belonging to capital good consumption good and energy sectors production and energy generation lead to greenhouse gas emissions which affect temperature dynamics climate damages are modelled at the individual level as stochastic shocks hitting workers labour productivity energy efficiency capital stock and inventories of firms in that aggregate damages emerge from the aggregation of losses suffered by heterogeneous interacting and boundedly rational agents the model is run focusing on a business as usual carbon intensive scenario consistent with a representative concentration pathway 8 5 we find that the dsk model is able to account for a wide ensemble of micro and macro empirical regularities concerning both economic and climate dynamics simulation experiments show a substantial lack of isomorphism between the effects of micro and macro level shocks as it is typical in complex system models in particular different types of shocks have heterogeneous impact on output growth unemployment rate and the likelihood of economic crises pointing to the importance of the different economic channel affected by the shock overall we report much larger climate damages than those projected by standard iams under comparable scenarios suggesting possible shifts in the growth dynamics from a self sustained pattern to stagnation and high volatility and the need of urgent policy interventions

biomass direct fired power generation system in china an integrated energy ghg emissions and economic evaluation for salix abstract to gain a better understanding of the options of biomass power generation in china this study presented an integrated energy environmental and economic evaluation for salix in china and a typical salix direct fired power generation system sdpgs in inner mongolia was selected for case study a tiered hybrid life cycle assessment lca model was developed to calculate the planting to wire ptw energy consumption greenhouse gas ghg emissions and economic cost and profit of the sdpgs including feedstock cultivation power plant construction and operation and on grid price with without government subsidies the results show that the ptw energy consumption and ghg emissions of salix are 0 8 mj kwh and 114 g co2 eq kwh respectively indicating an energy payback time epbt of 3 2 years the sdpgs is not economically feasible without government subsidies the ptw costs are dominated by feedstock cultivation the energy saving and ghg mitigation benefits are still robust even when the power plant runs at only 60 design capacity for future development of biomass power in china scientific planning is necessary to guarantee a sufficient feedstock supply in addition technology progress mature industrial chains and reasonable price setting policy are required to enable potential energy and environmental advantages of biomass power moving forward

optimal dynamic carbon taxes in a climate economy model with distortionary fiscal policy how should carbon be taxed as a part of fiscal policy the literature on optimal carbon pricing often abstracts from other taxes however when governments raise revenues with distortionary taxes carbon levies have fiscal impacts while they raise revenues directly they may shrink the bases of other taxes e g by decreasing employment this article theoretically characterizes and then quantifies optimal carbon taxes in a dynamic general equilibrium climate economy model with distortionary fiscal policy first this article establishes a novel theoretical relationship between the optimal taxation of carbon and of capital income this link arises because carbon emissions destroy natural capital they accumulate in the atmosphere and decrease future output consequently this article shows how the standard logic against capital income taxes extends to distortions on environmental capital investments second this article characterizes optimal climate policy in sub optimal fiscal settings where income taxes are constrained to remain at their observed levels third this article presents a detailed calibration that builds on the seminal dice approach but adds features essential for a setting with distortionary taxes such as a differentiation between climate change production impacts e g on agriculture and direct utility impacts e g on biodiversity existence value the central quantitative finding is that optimal carbon tax schedules are 8 24 lower when there are distortionary taxes compared to the setting with lump sum taxes considered in the literature

models as usual for unusual risks on the value of catastrophic climate change we study the role of alternative intertemporal preference representations in a model of economic growth stock pollutant and endogenous risk of catastrophic collapse we contrast the traditional discounted utility model which assumes risk neutrality with respect to intertemporal utility with a multiplicative choice model that displays risk aversion in that dimension first we show that both representations of preferences can rationalize the same business as usual economy for a given interest rate and no pollution externality second once we introduce a collapse risk whose hazard rate is a function of the pollution stock multiplicative preferences recommend a much more stringent policy response an illustration in the context of climate change indicates that switching to the multiplicative preference representation has a similar effect in terms of policy recommendations as scaling up the schedule of the hazard rate by a factor of 100

simple rules for climate policy and integrated assessment a simple integrated assessment framework that gives rules for the optimal carbon price transition to the carbon free era and stranded carbon assets is presented which highlights the ethical economic geophysical and political drivers of optimal climate policy for the ethics we discuss the role of intergenerational inequality aversion and the discount rate where we show the importance of lower discount rates for appraisal of longer run benefit and of policy makers using lower discount rates than private agents the economics depends on the costs and rates of technical progress in production of fossil fuel its substitute renewable energies and sequestration the geophysics depends on the permanent and transient components of atmospheric carbon and the relatively fast temperature response and we allow for positive feedbacks the politics stems from international free rider problems in absence of a global climate deal we show how results change if different assumptions are made about each of the drivers of climate policy our main objective is to offer an easy back on the envelope analysis which can be used for teaching and communication with policy makers

the effect of environmental policies on risk reductions in energy generation abstract we demonstrate that environmental policies can decrease the risks in energy generation for private investors when several renewable technologies are simultaneously triggered this is because diverse renewable technologies can hedge the intermittent generation of other forms of renewable power our study is distinct from previous literature which has not examined environmental policies through a risk reduction analysis or has only considered a few technologies such as wind and solar when analyzing risk reduction benefits this paper is important as environmental policies can be justified not only due to environmental benefits but also economically from a risk reduction perspective by using basic diversification gains

temperature and growth a panel analysis of the united states this paper documents that seasonal temperatures have significant and systematic effects on the u s economy both at the aggregate level and across a wide crosssection of economic sectors this effect is particularly strong for the summer an increase of 1 f in the average summer temperature is associated with a reduction in the annual growth rate of state level output of 0 15 to 0 25 percentage points when these estimates are combined with projected increases in seasonal temperatures it is found that a reduction of u s economic growth by up to one third could occur over the next century

choosing a monetary value of greenhouse gases in assessment tools a comprehensive review there is a societal need for using monetary estimates of social impacts of co2 and other greenhouse gases in different assessment tools such as cost benefit analysis and life cycle assessment a number of estimates are available in the literature since these differ by several orders of magnitude there is ambiguity and confusion about which to use this review aims to give some guidance on this issue the variation in carbon value estimates depends on several uncertain aspects which will remain uncertain including climate sensitivity assumptions about future emissions and decision makers ethical standpoints hence there is no single correct monetary value for co2 it will depend on the ethical standpoint of the user due to this estimates of social costs of co2 emissions cannot be used for calculating an optimal emission level although they can inform such assessments it is suggested that marginal abatement cost values are used for emissions capped by binding targets in short term assessments and that social cost of carbon values should be used for all other emissions benchmark principles for choosing a monetary carbon value are suggested along with associated estimates depending on the choices made with regard to ethical standpoints and assumptions about future emissions and climate sensitivity estimates can be significantly higher than the ones typically used in assessment tools today the estimates need continuous updating and there is need for better understanding and communication around the limitations and uncertainties involved

optimum growth and carbon policies with lags in the climate system we study the optimal carbon tax in an economy in which climate change stemming from polluting non renewable resource affects the economy s growth potential our main contribution is to introduce and explore the natural time lag of the climate system between emissions and damages to capital accumulation in an endogenous growth setting this allows us to investigate how optimal climate policy and its interplay with climate dynamics affect long run growth and the transition of the economy towards it without pollution decay a higher speed of emissions diffusion steepens the growth profile of the economy with pollution decay this leads to lower short run but higher long run economic growth during transition poor understanding of the emissions diffusion process leads to suboptimal carbon taxes resource extraction and growth

fossil fuels stock externalities and backstop technology the hotelling exhaustible resource model is extended to include stock pollution and nonpolluting backstop technology it is shown that an optimal energy consumption strategy typically includes a regime in which the two energy sources are consumed simultaneously along this regime fossil fuel consumption decreases and backstop consumption increases together fossil fuel and backstop consumption may form eleven optimal regime combinations a decrease in the backstop price decreases the initial level of optimal emission tax

second best renewable subsidies to de carbonize the economy commitment and the green paradox climate change must deal with two market failures global warming and learning by doing in renewable energy production the first best policy consists of an aggressive renewables subsidy in the near term and a gradually rising and falling carbon tax given that global carbon taxes remain elusive policy makers might have to rely on a second best subsidy only with credible commitment the second best subsidy is higher than the social benefit of learning to cut the transition time and peak warming close to first best levels at the cost of higher fossil fuel use in the short run weak green paradox without commitment the second best subsidy is set to the social benefit of learning it generates smaller weak green paradox effects but the transition to the carbon free takes longer and cumulative carbon emissions are higher under first best and second best with pre commitment peak warming is 2 1 2 3 circ c under second best without commitment 3 5 circ c and without any policy 5 1 circ c above pre industrial levels not being able to commit yields a welfare loss of 95 of initial gdp compared to first best being able to commit brings this figure down to 7

does a recession call for less stringent environmental policy a partial equilibrium second best analysis this paper analyses second best optimal environmental policy responses to real and financial shocks in a two period partial equilibrium model with heterogeneous firms an environmental externality and credit constraints we show that to alleviate credit constraints and encourage investment the second best optimal emission tax falls short of marginal emission damages the optimal response to shocks depends on how the shock affects the size of the environmental and credit market failures and the effectiveness of the tax in alleviating these market failures under mildly restrictive assumptions on functional forms the optimal response to a persistent negative productivity shock or a tightening of credit is to reduce the emission tax our results are informative for how climate change policy should optimally change with the business cycle

carbon dioxide emissions and international trade at the turn of the millennium we present a new dataset of geographical production final embodied production and consumption based carbon dioxide emission inventories covering 78 regions and 55 sectors from 1997 to 2011 we extend previous work both in terms of time span and in bridging from geographical to embodied production and ultimately to consumption we analyse the recent evolution of emissions the development of carbon efficiency of the global economy and the role of international trade as the distribution of responsibility for emissions across countries is key to the adoption and implementation of international environmental agreements and regulations the final production and consumption based inventories developed here provide a valuable extension to more traditional geographical production based criteria

bayesian learning growth and pollution abstract environmental problems such as climate change have great uncertainties current expectations are that uncertainties about climate change will be resolved quickly we examine this hypothesis theoretically and computationally we consider bayesian learning about the relationship between greenhouse gas levels and global mean temperature changes a key uncertainty learning is non trivial because of a stochastic shock to the realized temperature we find theoretically the expected learning time which is related to the variance of the shock and the emissions policy implying a tradeoff between the benefits of controlling emissions and information we imbed the learning model into an optimal growth model with a climate sector and solve the resulting dynamic program we find computationally that learning takes on average over 90 yr far longer than currently believed

econometrics and business cycle empirics business cycle empirics have long been a central arena for the debate about the roles of economic theory and econometrics in modelling economic time series data some famous historical examples are moore i9i4 keynes i939 and koopmans i947 sources for potential disagreements include that the entire economic system is involved and unobservable stochastic forces seem more than usually prominent in determining the outcome not only do these constitute two aspects about which it is hard to theorise they are equally difficult to model empirically there are both positive arguments for and negative arguments against according a dominant role to either theory or evidence not least because it is unclear what constitutes admissible instances of either in the absence of the other we first review what precludes a purely theoretical approach what prevents a purely empirical approach and hence why an interactive approach is imperative even so both the relative importance of the two ingredients and their substantive contents are likely to remain at issue first concerning the economy considerable empirical evidence suggests that it is a dynamic non linear high dimensional and evolving entity so studying it is difficult society and social systems alter over time laws change and technological innovations occur so establishing any invariants of an economic system is not easy such difficulties adversely afflict both theory and empirical modelling secondly concerning the observations time series data in economics are heterogeneous non stationary time dependent and interdependent so it is difficult to acquire knowledge from the available empirical information again such factors also make it hard to theorise about the properties of the underlying system a more direct critique of the empirical enterprise is that samples are short and highly aggregated economic magnitudes are inaccurately measured are subject to considerable revision and important variables are not measured or are unobservable so inferences are both imprecise and tentative combined with the simultaneity non constancy and high dimensionality of economic data a purely empirical approach seems to many to be precluded other criticisms of econometric approaches include worries about data mining pretest biases a lack of genuine identifiability and collinearity sometimes combined with a belief that theory can compensate an overemphasis on a

energy transition under irreversibility a two sector approach in this paper we analyze the optimal energy transition of a two sector economy energy and final goods with exhaustible oil reserves a renewable source of energy and a pollution threat the latter corresponds to a pollution threshold above which a part of the capital is lost following flooding for instance we show that the optimal energy transition path may correspond to a corner regime in which the economy starts using both resources then crosses the pollution threshold and therefore loses a part of its capital at the end the sole adoption of the renewable energy is optimal only in the long run this result is in line with the asymptotic energy transition arguments stating that the transition to clean energy may happen only in the long run we also show that economy reduces the use of energy resource as long as the productivity of capital and energy services is high therefore public policies should promote investments in energy innovation that targets productive sector home appliances and buildings and helps to save both money and energy we extend the present model to allow for additional investment in energy saving technologies our main results show that this additional investment favours the energy transition in the sense that it increases the time within which the economy may experience the catastrophe and the welfare of the society for policy implications economic instruments such as taxes on dirty energy subsidies on clean energy or incentives for energy saving technologies need to be implemented in order to promote the energy transition this is particularly important for developing countries that mostly rely on polluting energy resources and are the most vulnerable to climate change but those economic instruments should be carefully designed in line with the asymptotic energy transition result

idiosyncratic production risk growth and the business cycle we introduce a neoclassical growth economy with idiosyncratic production risk and incomplete markets each agent is an entrepreneur operating her own technology with her own capital stock the general equilibrium is characterized by a closed form recursion in the cara normal case incomplete markets introduce a risk premium on private equity which reduces the demand for investment as compared to complete markets the steady state can thus have both a lower capital stock due to investment risk and a lower interest rate due to precautionary savings furthermore the anticipation of high real interest rates in the future feeds back into high risk premia and low investment in the present thus slowing down convergence to the steady state our results highlight the importance of private risk premia for capital accumulation and business cycles

on modeling and interpreting the economics of catastrophic climate change with climate change as prototype example this paper analyzes the implications of structural uncertainty for the economics of low probability high impact catastrophes even when updated by bayesian learning uncertain structural parameters induce a critical tail fattening of posterior predictive distributions such fattened tails have strong im plications for situations like climate change where a catastrophe is theoretically possible because prior knowledge cannot place sufficiently narrow bounds on overall damages this paper shows that the economic consequences of fat tailed structural uncertainty along with unsureness about high temperature damages can readily outweigh the effects of discounting in climate change policy analysis