time orientation and asset prices we analyze a general equilibrium asset pricing model where a small subset of the consumers investors have a short run urge to save that is their attitude toward consumption in the long run is a standard one f they do place zero weight on consumption far enough out in the future f but their short run effective rates of discount may be negative our model which is an elaboration on the framework proposed by faruk gul and wolfgang pesendorfer does not feature time inconsistencies thus we view consumers as fully rational but subject to specific internal frictions in the form of temptation and self control problems the model nests the mehra prescott model and we use it as a way of interpreting the wealth and asset pricing data some aspects of these data we argue can possibly be better understood using our model than the standard one r 2002 published by elsevier science b v

government policy with time inconsistent voters behavioral economics presents a paternalistic rationale for benevolent government intervention this paper presents a model of public debt where voters have self control problems and attempt to commit using illiquid assets in equilibrium government accumulates debt to respond to individuals desire to undo their commitments which leads individuals to rebalance their portfolio in turn feeding into a demand for further debt accumulation as a consequence i large and distortionary government debt accumulation occurs and ii banning illiquid assets could improve individuals welfare these results offer a new rationale for balanced budget rules in constitutions to restrain governments responses to voters self control problems

temptation and social security in a dynastic framework abstract we investigate welfare and aggregate implications of a pay as you go payg social security system in a dynastic framework in which individuals have self control problems the presence of self control problems induces individuals to save less because of their urge for temptation towards current consumption individuals efforts to balance between the short term urge for temptation and the long term commitment for consumption smoothing result in self control costs in this environment payg social security works as a self control cost reducing device in contrast the presence of altruism induces individuals to save more this in turn mitigates the adverse effects of self control problems and payg social security on savings but magnifies the self control costs we find that in our environment the adverse welfare effects of a payg system are further mitigated relative to the environments that incorporate altruism and self control issues separately however the level of mitigation is quite modest

european union commitment towards res market penetration from the first legislative acts to the publication of the recent guidelines on state aid 2014 2020 during the last three decades the european union eu commitment towards the renewable energy sources res market penetration has been very complex involving several aspects pertaining to the economic and political action of member states this paper seeks to overview the historical development of the legislative eu framework including a description of the main financial programmes established and managed by the eu directorates general moreover the work will proceed with the picture of some investment funds ad hoc created for res undertakings and managed by the european investment bank eib in collaboration with the eu or other foreign bank institutes the delicate matter of state aid is discussed paying particular attention to the transition from 1999 to the recent eu guidelines 2014 2020 as these wider scopes could lead to an effective and well functioning european energy single market focusing the attention on three case studies we have produced final remarks on the correct functioning of the eu political framework giving attention to important improvements needed at infrastructural level the eu awareness of the power grid limits that are currently recorded in europe has lead to further reforms of the legislation as shown by the new eu guidelines that will probably support member states in dealing with the infrastructure challenge

foreign exchange market intervention and expectations the yen dollar exchange rate abstract using press reports and official statistics on central bank intervention in conjunction with options market data we find that central bank intervention had no statistically significant systematic impact on the mean or higher moments of the exchange rate during 1993 2000 we also find that japanese authorities appeared to intervene mainly in response to deviations of the exchange rate from some implicit target levels and to a rise in market uncertainty u s monetary authorities intervened only in cooperation with the japanese authorities

do central bank foreign exchange interventions affect market expectations the aim of this article is to study the impact of the brazilian central bank swap interventions on the fx market from 2006 to 2013 in this period these nontraditional interventions were the main

the hyperbolic consumption model calibration simulation and empirical evaluation ur preferences for the long run tend to conflict with our short run behavior when planning for the long run we intend to meet our deadlines exercise regularly and eat healthfully but in the short run we have little interest in revising manuscripts jogging on the stairmaster and skipping the chocolate souffleala mode delay of gratification is a nice long term goal but instant gratification is disconcertingly tempting this gap between long run intentions and short run actions is apparent across a wide range of behaviors including saving choices a 1997 survey found that 76 percent of respondents believe they should be saving more for retirement looking only at respondents who believed they were at an age where you should be seriously saving already the survey found that 55 percent reported being behind in their savings and only 6 percent reported being ahead farkas and johnson 1997 the report on the survey concluded t he gaps between people s atti tudes intentions and behavior are troubling and threaten increased insecurity and dissatisfaction for people when they retire americans are simply not doing what logic and their own reasoning suggests they should be doing a 1993 luntz webber merrill lynch survey found similar answers when baby boomers were asked what percentage of your annual household income do you think you should save for retirement and what percentage of your annual

dynamic nonlinear income taxation with quasi hyperbolic discounting and no commitment this paper examines a dynamic model of nonlinear income taxation in which the government cannot commit to its future tax policy and individuals are quasi hyperbolic discounters who cannot commit to future consumption plans the government has both paternalistic and redistributive objectives and therefore uses its taxation powers to maximize a utilitarian social welfare function that reflects individuals true long run preferences under first best taxation quasi hyperbolic discounting exerts no effect on the level of social welfare attainable under second best taxation quasi hyperbolic discounting increases resp decreases the level of social welfare attainable when separating resp pooling taxation is optimal in stark contrast to previous studies this result implies that some individuals can actually be better off in the long run as a result of their short run impatience

reading pibor futures options smiles the 1997 snap election abstract in this paper we compare various methods that extract a risk neutral density rnd out of pibor interest rate futures options and we investigate how traders react to a political event our benchmark model derives from a brace d gatarek m musiela mathematical finance 7 1997 127 155 we also consider a mixture of log normals as in w r melik c p thomas journal of financial and quantitative analysis 32 1997 91 116 an hermite expansion as in p abken d b madan s ramamurtie estimation of risk neutral and statistical densities by hermite polynomial approximation with an application to eurodollar futures options federal reserve bank of atlanta 1996 and a method based on maximum entropy according to p buchen m kelly journal of financial and quantitative analysis 31 1996 143 159 we take care of the early exercise feature and we show how to approximate rnds for a fixed time to maturity the various methods generate similar rnds a daily panel of options running from february 1997 to july 1997 reveals that operators expected the snap election a few days before the official announcement was made and that a substantial amount of political uncertainty subsisted even a month after the elections uncertainty evolved with polls forecasts of the future government

when do central bank interventions influence intra daily and longer term exchange rate movements this paper examines dollar interventions by the g3 since 1989 and the reasons that trader reactions to these interventions might differ over time and across central banks market microstructure theory provides a framework for understanding the process by which sterilized central bank interventions are observed and interpreted by traders and how this process in turn might influence exchange rates using intra daily and daily exchange rate and intervention data the paper analyzes the influence of interventions on exchange rate volatility finding evidence of both within day and daily impact effects but little evidence that interventions influence longer term volatility

the international monetary system an analysis of alternative regimes abstract this is an exercise in the positive economics of alternative monetary regimes the behavior of output and prices is compared using a stochastic specification which allows asymptotic variances to be obtained without difficulty free floating of exchange rates together with national money supply targets is analyzed first with and without the presence of fads in the exchange rate two alternatives for monetary coordination are then considered first is mckinnon s proposal to fix nominal exchange rates and stabilize aggregate monetary growth or average inflation second is williamson s system of target zones for stable real exchange rates complemented by nominal income targets for fiscal policy

physical market determinants of the price of crude oil and the market premium abstract we analyze the determinants of the real price of crude oil by means of an equilibrium correction model over the last two decades where we focus on the aspects of the physical market that impact on the clearing price we find that two cointegrating relations affect the changes in prices one refers to opec s behavior attempting to control prices using its market power and quotas the other to the coverage rate of oecd expected future demand using inventory behaviors we derive a forecasting equation for the change in oil prices which we use to assess the speculative elements of the price increases of the period 2000 05 we show that worries alien to the physical markets were the causes of the increase in oil prices and we quantify their overall impact

estimating temptation and commitment over the life cycle this paper estimates the importance of temptation gul and pesendorfer 2001 for consumption smoothing and asset accumulation in a structural life cycle model we use two complementary estimation strategies rst we estimate the euler equation of this model and second we match liquid and illiquid wealth accumulation using the method of simulated moments we nd that the utility cost of temptation is one quarter of the utility bene t of consumption further we show that allowing for temptation is crucial for correctly estimating the elasticity of intertemporal substitution estimates of the eis are substantially higher than without temptation finally our method of simulated moments estimation is able to match well the life cycle accumulation pro les for both liquid and illiquid wealth only if temptation is part of the preference speci cation our ndings on the importance of temptation are robust to the di erent estimation strategies revised july 2020

using option prices to estimate realignment probabilities in the european monetary system the case of sterling mark abstract this paper describes a procedure for estimating the market s perceived probability distribution of future exchange rates from the prices of risk reversals strangles and other currency options and uses the procedure to estimate the risk neutral ex ante probability of a realignment of the pound sterling the procedure for estimating the realignment probabilities relies on the jump diffusion model of exchange rate behavior and the resulting option pricing formula by fitting this model to market option price data i retrieve the unobserved parameters of the jump diffusion process i then use these parameter estimates to estimate the ex ante probability distribution of exchange rates and thus the realignment probabilities

high frequency analysis of foreign exchange interventions what do we learn abstract the high frequency analysis of foreign exchange dynamics is helpful in order to better identify the impact of central bank interventions evidence robustly shows that interventions do indeed move the exchange rate level in the desired direction interventions increase volatility in the short run as they are regarded as information but they can reduce volatility overall ways of transmission may reach beyond the signalling channel and also include the portfolio balance and a damping channel finally interventions are more successful if they obey certain conditions such as being coordinated among central banks and going with the market and fundamentals

reading the smile the message conveyed by methods which infer risk neutral densities abstract in this study we compare the quality and information content of risk neutral densities obtained by various methods we consider a non parametric method based on a mixture of log normal densities the semi parametric ones based on an hermite approximation or based on an edgeworth expansion the parametric approach of malz which assumes a jump diffusion for the underlying process and heston s approach assuming a stochastic volatility model we apply those models on ff dm exchange rate options for two dates models differ when important news hits the market here anticipated elections the non parametric model provides a good fit to options prices but is unable to provide as much information about market participants expectations than the jump diffusion model

u s intervention assessing the probability of success this paper estimates the unconditional and conditional probabilities that u s interventions successfully smooth short term mark dollar and yen dollar exchange rates the sample period extends from february 1987 to february 1990 assuming a binomial distribution the number of observed successes usually is greater than one would expect to see randomly results from a logit model suggest that coordinated intervention has a higher probability of success than unilateral intervention the probability of success also increases with the dollar amount of an intervention other conditioning variables are not significant the paper presents a reaction function with adjustments for the incidentally truncated nature of intervention data predicted values serve as instruments for intervention in the logit models

eliciting temptation and self control through menu choices a lab experiment unlike present biased individuals agents who suffer self control costs as in gul and pesendorfer 2001 may choose to restrict their choice set even when they expect to resist temptation to identify these self control types i design an experiment in which the temptation was to read a story during a tedious task the identification strategy relies on a two step procedure first i measure commitment demand by eliciting subjects preferences over menus that did or did not allow access to the story i then implement preferences using a random mechanism allowing to observe subjects who faced the choice yet preferred commitment a quarter to a third of subjects can be classified as self control types according to their menu preferences when confronted with the choice virtually all of them behaved as they anticipated and resisted temptation these findings suggest that policies restricting the availability of tempting options could have larger welfare benefits than predicted by standard models of present bias

fiscal rules and discretion in a world economy governments are present biased toward spending fiscal rules are deficit limits that trade off commitment to not overspend and flexibility to react to shocks we compare coordinated rules chosen jointly by a group of countries to uncoordinated rules if governments present bias is small coordinated rules are tighter than uncoordinated rules individual countries do not internalize the redistributive effect of interest rates however if the bias is large coordinated rules are slacker countries do not internalize the disciplining effect of interest rates surplus limits enhance welfare and increased savings by some countries or outside economies can hurt the rest

when will fossil fuel reserves be diminished crude oil coal and gas are the main resources for world energy supply the size of fossil fuel reserves and the dilemma that when non renewable energy will be diminished is a fundamental and doubtful question that needs to be answered this paper presents a new formula for calculating when fossil fuel reserves are likely to be depleted and develops an econometrics model to demonstrate the relationship between fossil fuel reserves and some main variables the new formula is modified from the klass model and thus assumes a continuous compound rate and computes fossil fuel reserve depletion times for oil coal and gas of approximately 35 107 and 37 years respectively this means that coal reserves are available up to 2112 and will be the only fossil fuel remaining after 2042 in the econometrics model the main exogenous variables affecting oil coal and gas reserve trends are their consumption and respective prices between 1980 and 2006 the models for oil and gas reserves unexpectedly show a positive and significant relationship with consumption while presenting a negative and significant relationship with price the econometrics model for coal reserves however expectedly illustrates a negative and significant relationship with consumption and a positive and significant relationship with price consequently huge reserves of coal and low level coal prices in comparison to oil and gas make coal one of the main energy substitutions for oil and gas in the future under the assumption of coal as a clean energy source

intergenerational disagreement and optimal taxation of parental transfers we study optimal taxation of bequests and inter vivos transfers in a model where altruistic parents and their offspring disagree on intertemporal trade offs we show that the laissez faire equilibrium is pareto inefficient and whenever offspring are impatient from their parents perspective optimal policy involves a positive tax on parental transfers cautioned by the technical complications present in this class of models our normative prescriptions do not rely on the assumption of differentiability of the agents policy functions

a new method for identifying the effects of foreign exchange interventions central banks react even to intraday changes in the exchange rate however in most cases intervention data is available only at a daily frequency this temporal aggregation makes it difficult to identify the effects of interventions on the exchange rate we apply the bayesian mcmc approach to this endogeneity problem we use data augmentation to obtain intraday intervention amounts and estimate the efficacy of interventions using the augmented data applying this new method to japanese data we find that an intervention of one trillion yen moves the yen dollar rate by 1 7 percent which is more than twice as much as the magnitude reported in previous studies applying ols to daily observations this shows the quantitative importance of the endogeneity problem due to temporal aggregation

intervention strategies and exchange rate volatility a noise trading perspective abstract this paper estimates and explains the impacts of sterilized us intervention on exchange rate volatility i find that intervention reduced both yen dollar and dm dollar exchange rate volatilities during 1985 1986 but increased them during 1987 1989 these results are explained in a noise trading framework where the effectiveness of sterilized intervention may depend critically on the design and implementation of intervention strategies jel f31 1997 elsevier science ltd

redistributive taxation in a simple perfect foresight model abstract we investigate the redistributive potential of capital taxation in an intertemporal maximizing model of capital formation first even unanticipated redistributive capital taxation is severely limited in its effectiveness since it depresses wages second under any convergent redistributive tax policy which maximizes a paretian social objective the capital income tax will converge to zero independent of the factor supply elasticities these results are independent of workers holdings of capital

assessing bankruptcy reform in a model with temptation and equilibrium default abstract a life cycle model with equilibrium default in which agents with and without temptation coexist is constructed to evaluate the 2005 bankruptcy law reform the calibrated model indicates that the 2005 reform reduces bankruptcies as seen in the data and improves welfare as lower default premia allows better consumption smoothing a counterfactual reform of changing income garnishment rate is also investigated interesting contrasting welfare effects between two types of agents emerge agents with temptation prefer a lower garnishment rate as tighter borrowing constraint prevents them from over borrowing while those without prefer better consumption smoothing enabled by a higher garnishment rate

solar pv where the sun doesn t shine estimating the economic impacts of support schemes for residential pv with detailed net demand profiling abstract countries with low irradiation and solar pv adoption rates are increasingly considering policy support for solar pv although consumer electricity demand and solar generation profiles are often mismatched this paper presents a methodology for policymakers in such conditions to examine more precisely the financial performance of residential solar pv from the consumer perspective as part of an ex ante policy assessment we model a range of prospective policy scenarios and compare policy mechanisms that compensate homeowners for generation those that reduce their upfront costs and those that assist with financing using ireland as a case study the results confirm the intuitive notion that more generous financial remuneration schemes provide quicker payback however we observe that in low irradiance regions there is little difference between upfront grants and feed in tariffs to accelerate payback timeframes we also show the importance of retail tariff structure in consumer payback for solar pv systems with one part tariffs generating shorter paybacks than two part tariff structures although the latter is more likely to secure revenue for electricity infrastructure investment drawing from this analysis the paper proposes some options for the design of policy supports and tariff structures to deliver a sustainable residential renewable electricity system in low irradiance regions

temptation and taxation we study optimal taxation when consumers have temptation and self control problems embedding the class of preferences developed by gul and pesendorfer into a standard macroeconomic setting we first prove in a two period model that the optimal policy is to subsidize savings when consumers are tempted by excessive impatience the savings subsidy improves welfare because it makes succumbing to temptation less attractive we then study an economy with a long but finite horizon which nests as a special case the phelps pollak laibson multiple selves model thereby providing guidance on how to evaluate welfare in this model we prove that when period utility is logarithmic the optimal savings subsidies increase over time for any finite horizon moreover as the horizon grows large the optimal policy prescribes a constant subsidy in contrast to the well known chamley judd result

temptation and self control some evidence and applications this paper studies the empirical relevance of temptation and self control using household level data from the consumer expenditure survey we construct an infinite horizon consumption savings model that allows but does not require temptation and self control in preferences in the presence of temptation a wealth consumption ratio in addition to consumption growth becomes a determinant of the asset pricing kernel and the importance of this additional pricing factor depends on the strength of temptation to identify the presence of temptation we exploit an implication of the theory that a more tempted individual should be more likely to hold commitment assets such as individual retirement account ira or 401 k accounts our estimation provides empirical support for temptation preferences based on our estimates we explore some quantitative implications of this class of preferences for capital accumulation in a neoclassical growth model and the welfare cost of the business cycle

a friction model of daily bundesbank and federal reserve intervention abstract this paper takes a novel approach to derive a central bank intervention reaction function a garch model for exchange rates is amended to allow interventions to have an effect on both the mean and the variance of exchange rate returns an intervention reaction function is obtained by combining the model with a loss function for the central bank estimation results for the implied friction model reproduce the familiar leaning against the wind policy by the bundesbank and the federal reserve furthermore the central banks appear to have reacted to increases in the conditional variance of daily dm returns

is there evidence of fear of appreciation in china s foreign exchange market intervention abstractusing the data after the exchange rate regime reform in july 2005 this paper systematically studied the issue whether china has conducted fear of appreciation asymmetric intervention th

voting under temptation abstract within the confines of linear tax and complete market we show that the efficiency force for a negative capital tax may not be strong enough to reverse the politico economic force for a positive redistributive taxation under temptation and self control preferences

optimal life cycle capital taxation under self control problems we study optimal taxation of savings in an economy where agents face self control problems and we allow the severity of self control to change over the life cycle we focus on quasi hyperbolic discounting with constant elasticity of inter temporal substitution utility functions and linear markov equilibria we derive explicit formulas for optimal taxes that implement the efficient commitment allocation we show analytically that if agents ability to self control increases concavely with age then savings should be subsidised and the subsidy should decrease with age we also study the quantitative effects of age dependent self control problems and find that the optimal subsidies in our environment are much larger than those implied by models with constant self control finally we compare our optimal subsidies with those implied by the 401 k plan although the subsidy levels in the two cases are of comparable magnitudes the 401 k plan implies an increasing pattern of subsidies while the optimal subsidies decrease over the life cycle

re evaluating the role of energy efficiency standards a behavioral economics approach abstract the economic models that prescribe pigovian taxation as the first best means of reducing energy related externalities are typically based on the neoclassical model of rational consumer choice yet consumer behavior in markets for energy using durables is generally thought to be far from efficient giving rise to the concept of the energy efficiency gap this paper presents a welfare analysis of energy policies that is based on a behavioral model of temptation and self control introduced by gul and pesendorfer 23 24 we find that in the presence of temptation i pigovian taxes alone do not yield a first best outcome ii when viewed as substitutes energy efficiency standards can dominate pigovian taxes and iii a policy combining standards with a pigovian tax can yield higher social welfare than a pigovian tax alone implying that the two instruments should be viewed as complements rather than substitutes

analysis of renewable energies in european union abstract the paper s main research objective is to analyse the renewable energy sector in the european union member states the first step of the research was to generate clusters of countries based on the share of renewables in total energy produced and the countries energy dependence in order to generate the clusters we applied the k means clustering method based on the data obtained from eurostat by using the statistical package for the social sciences three clusters of countries have been generated in the next step the eu states were ranked based on the following criteria share of renewable energy sources share of renewable electricity share of renewable heating and cooling and share of renewable energy in transport then the main characteristics of the renewable energy policy in each member state have been highlighted

intraday effects of foreign exchange intervention by the bank of japan abstract we examine the effects of intervention by the bank of japan using intraday data from oct 1 1992 to sept 30 1993 news related to the bank of japan s intervention in the jpy market was retrieved from reuters headlines we find that jpy volatility varies significantly differently across periods from 1 h before to 1 h after reuters intervention reports results from arch models show that intervention by the bank of japan has a positive and significant impact on jpy volatility particularly at high frequencies 5 and 10 min intervals we also find that our intervention proxy has the largest effect upon high frequency volatility 30 to 45 min prior to reuters reports

procrastination and obedience in this lecture i shall focus on situations involving repeated decisions with time inconsistent behavior although each choice may be close to maximizing and therefore result in only small losses the cumulative effect of a series of repeated errors may be quite large thus in my examples decision makers are quite close to the intelligent well informed individuals usually assumed in economic analysis but cumulatively they make seriously wrong decisions that do not occur in standard textbook economics this lecture discusses and illustrates several pathological modes of individual and group behavior procrastination in decision making undue obedience to authority membership of seemingly normal individuals in deviant cult groups and escalation of commitment to courses of action that are clearly unwise in each case individuals choose a series of current actions without fully appreciating how those actions will affect future perceptions and behavior the standard assumption of rational forwardlooking utility maximizing is violated the nonindependence of errors in decision making in the series of decisions can be explained with the concept from cognitive psychology of undue salience or vividness for example present benefits and costs may have undue salience relative to future costs

is foreign exchange intervention effective some microanalytical evidence from the czech republic abstract i estimate a two equation system on the czech koruna euro exchange rate and order flow at hourly frequency with transactions data from the reuters spot matching market in the second half of 2002 during which the czech national bank intervened to stem the appreciation of the koruna i find a significant impact of order flow on the exchange rate equal to 7 6 basis points per 10 million of which 80 persists throughout the day the news of intervention increases the price impact of order flow by 3 9 basis points per 10 million the order flow equation yields inconclusive results

the crash of ʼ87 was it expected the evidence from options markets transactions prices of s p 500 futures options over 1985 1987 are examined for evidence of expectations prior to october 1987 of an impending stock market crash first it is shown that out of the money puts became unusually expensive during the year preceding the crash second a model is derived for pricing american options on jump diffusion processes with systematic jump risk the jump diffusion parameters implicit in options prices indicate that a crash was expected and that implicit distributions were negatively skewed during october 1986 to august 1987 both approaches indicate no strong crash fears during the 2 months immediately preceding the crash attempts to explain what caused the stock market crashes around the world in october 1987 have suffered from the paucity of major economic developments occurring around that time that could have triggered the crashes shifting expectations regarding monetary policy foreign investors fears of a dollar decline increasing riskiness of assets none of these appeared major enough if present at all to explain the magnitude of the crashes and although portfolio insurance strategies could conceivably magnify the effects of a jump in fundamentals the initiating jump in fundamentals appears to be lacking

the future of the feed in tariff fit scheme in europe the case of photovoltaics abstract the key objective of this study is the examination of the regulatory and policy framework of the feed in tariff fit scheme specifically its effect on both the electricity pricing as well as the local and european renewable energy sources res market and accordingly the definition of its feasibility as a scheme for the further development and promotion of renewable energy technologies rets this work discusses the fit scheme implementation for photovoltaics pvs in four case study countries denmark germany cyprus and spain a model describing the conditions under which a fit scheme is led to collapse is also introduced and a parametric analysis towards revealing the sensitivity of the different parameters affecting it is delivered the study concludes with significant policy implications that should be considered for future implementation of the scheme for the prevention of the collapse of the scheme the tariff s value ought to be determined by each country s government based on a set of influencing factors including the operational capital and investment costs of each ret the standard cost of renewable energy re generation and the avoidance cost which would be regularly reviewed depending on the excess of the annual capacity

do asset demand functions optimize over the mean and variance of real returns a six currency test abstract international asset demands are functions of expected returns optimal portfolio theory tells us that the coefficients in this relationship depend on the variance covariance matrix of real returns but previous estimates of the optimal portfolio 1 assume expected returns constant and 2 are not set up to test the hypothesis of mean variance optimization we use maximum likelihood estimation to impose a constraint between the coefficients and the error variance covariance matrix for a portfolio of six currencies we are able statistically to reject the constraint evidently investors are either not sophisticated enough to maximize a function of the mean and variance of end of period wealth or else are too sophisticated to do so

why do central banks intervene abstract intervention by central banks in terms of buying and selling foreign currency has been a major activity in recent years this paper investigates the motivations for such policy and the evidence for its effectiveness we use high quality daily data on the dollar amounts of intervention by the central banks of the us and germany we also use information on agreed g7 target levels for the dm and yen nominal exchange rates daily nominal dollar exchange rate returns are well described as a martingale garch process and we find little evidence that the different types of intervention have had much effect on the conditional mean of exchange rate returns there is some evidence that intervention is associated with slight increases in the volatility of exchange rate returns while little evidence is found for the effectiveness of intervention the motivations are more clear in particular from the application of probit analysis we find that the probability of intervention is determined by the magnitude of the deviation of the nominal exchange rate from the agreed target level and to a lesser extent by the current volatility of exchange rates

foreign exchange market interventions and the exchange rate in the long run this article examines whether foreign exchange market interventions conducted by the bank of japan are important for the dollar yen exchange rate in the long run we rely on a re examination of the empirical performance of a monetary exchange rate model this is basically not a new topic however we focus on two new questions first does the consideration of periods of massive interventions in the foreign exchange market uncover a potential long run relationship between the exchange rate and its fundamentals second do forex interventions support the adjustment towards a long run equilibrium value our results suggest that taking periods of interventions into account within a monetary model does improve the goodness of fit of an identified long run relationship to a significant degree furthermore forex interventions increase the speed of adjustment towards long run equilibrium in some periods particularly in periods of coordinated forex interventions our results indicate that only coordinated inter

recovering an asset s implied pdf from option prices an application to crude oil during the gulf crisis we develop a general method for estimating the implied martingale equivalent probability density function pdf for futures prices from american options prices the early exercise feature of american options precludes expressing the price of the option in terms of the pdf there exist tight bounds for the price of american options in terms of the pdf we demonstrate how these bounds together with observed option prices can be used to estimate the parameters of the pdf we estimate the distribution for crude oil during the persian gulf crisis and find the distribution differs significantly from that recovered using standard techniques

impact of macro economic surprises on carry trade activity abstract can official news and policy announcements affect foreign exchange speculation a widespread speculative strategy in foreign exchange markets is carry trade this paper explores the links between macro economic news and foreign exchange options to identify macro economic fundamentals most relevant to the pricing of downside risk measured by risk reversals options contracts to carry trade activity focusing primarily on the japanese yen carry trade we identify a significant impact of macro economic surprises on dollar yen risk reversals the effect is sizeable with news related to bilateral trade balance of particular concern moreover there is a close link between risk reversals and speculative futures positions in japanese yen this allows us to quantify a substantial effect of macro economic news on carry trade activity with the cost of hedging as the transmission mechanism

testing the portfolio balance model a multi lateral approach abstract this paper estimates outside bond demand equations from the portfolio balance model of exchange rate determination for five currencies the approach used in this paper differs from other structural studies of the portfolio balance model in two fundamental ways first while previous studies limit the portfolio choice to domestic assets relative to a composite foreign asset the model analyzed in this paper decomposes the foreign asset by currency second exploiting the cross equation correlation that arises from this decomposition provides more efficient estimates of the asset market parameters

crowd out education and employer contributions to workplace pensions evidence from canadian tax records this study assesses whether workplace pensions help individuals overcome knowledge barriers to saving for retirement using administrative data from canada and exploiting unique features of the pension system i find compelling evidence that each 1 contributed to workplace pensions partially crowds out other retirement saving by approximately 0 50 among interior savers in a regression kink design centering on unionized workers for methodological reasons further analysis indicates active versus passive decisions are influenced by education exploiting compulsory schooling reforms for identification i conclude by showing pension and education reform are both viable mechanisms for boosting saving from a life cycle perspective jel codes e21 h30 i21 j32

solar energy markets economics and policies abstract solar energy has experienced phenomenal growth in recent years due to both technological improvements resulting in cost reductions and government policies supportive of renewable energy development and utilization this study analyzes the technical economic and policy aspects of solar energy development and deployment while the cost of solar energy has declined rapidly in the recent past it still remains much higher than the cost of conventional energy technologies like other renewable energy technologies solar energy benefits from fiscal and regulatory incentives including tax credits and exemptions feed in tariff preferential interest rates renewable portfolio standards and voluntary green power programs in many countries the emerging carbon credit markets are expected to provide additional incentives to solar energy deployment however the scale of incentives provided by the existing carbon market instruments such as the clean development mechanism of the kyoto protocol is limited despite the huge technical potential the development and large scale deployment of solar energy technologies world wide still has to overcome a number of technical financial regulatory and institutional barriers the continuation of policy supports might be necessary for several decades to maintain and enhance the growth of solar energy in both developed and developing countries

the revealed preference theory of changing tastes we analyse preferences over finite decision problems in order to model decision makers with changing tastes we provide conditions on these preferences that identify the strotz model of consistent planning building on an example given by peleg and yaari 1973 we show that for problems with infinitely many choices strotz s representation of preferences may not be well defined for that case we propose a well defined approximation which is empirically indistinguishable from the strotz preference that is being approximated

self command in practice in policy and in a theory of rational choice an increasingly familiar occurrence for obstetricians is being asked by patients to withhold anesthesia during delivery the physician often proposes that a facemask be put beside the patient who may inhale nitrous oxide as she needs it but some determined patients ask that no such opportunity be provided if gas is available they will use it and they want not to be able to the request is interesting for decision theory and raises questions of ethics policy and physician responsibility even if the woman is merely making a mistake if she simply does not know how painful labor will be and how glad she will be even in retrospect if the pain is relieved but some women who make this request have had earlier deliveries during which they demanded anesthesia and received it they are acquainted with the pain they anticipate asking for relief and they want it withheld when they do they expect to regret afterwards any recourse to anesthesia this particular instance of attempted selfdenial has features that are special but many that are common the woman is so far as we know in good health physically and mentally she anticipates a transient period when her usual values and preferences will be suspended or inaccessible she has reasons for wanting to frustrate her own wishes at the critical time she needs cooperation she may ratify her choice afterward by expressing herself grateful that no anesthesia was offered even when requested there are ethical dilemmas and legal issues and there is conflict if say the husband disagrees with the physician in the delivery room about what his wife really wants

order flow and central bank intervention an empirical analysis of recent bank of japan actions in the foreign exchange market abstract this paper examines the behaviour of end user order flows in the foreign exchange market around periods of intense and large scale intervention activity by the bank of japan first we find very limited evidence that corporate customers are more than usually likely to be net sellers of yen on days when the bank of japan is intervening to sell yen however there is somewhat stronger evidence that financial customers are more likely to be net buyers of yen on the same days second we find very clear evidence that intervention matters in a microstructure analysis the strong contemporaneous correlation between order flows and exchange rate changes essentially disappears on days in which the bank of japan intervenes

equilibrium welfare and government policy with quasi geometric discounting abstract we consider a representative agent equilibrium model where the consumer has quasi geometric discounting and cannot commit to future actions we restrict attention to a parametric class for preferences and technology and solve for time consistent competitive equilibria globally and explicitly we then characterize the welfare properties of competitive equilibria and compare them to that of a planning problem the planner is a consumer representative who without commitment but in a time consistent way maximizes his or her present value utility subject to resource constraints the competitive equilibrium results in strictly higher welfare than the planning problem whenever the discounting is not geometric journal of economic literature classification numbers e21 e61 e91

the role for long run target values of the exchange rate in the bank of japan s policy reaction function this paper analyses whether the bank of japan boj had fundamental concepts in mind when carrying out interventions in the foreign exchange market we start by considering different long run fundamental target values based on a monetary exchange rate model and compare them with more ad hoc targets based on these findings we explain the intervention probability for the boj after 1991 based on an ordered probit model by accounting for subperiods and asymmetric effects it turns out that estimated fundamentally based values for the exchange rate provide additional information for the decision to intervene in particular after 1995 however short run ad hoc targets seem to be very important in particular from 1991 until 1995 while medium run ad hoc targets gain importance at the end of the 1990s overall we find a leaning against the wind strategy in the event of overvaluation relies on ad hoc targets while intervention in cases of undervaluation seems to be guided more strongly by deviations from fundamental values

temptation and forward guidance abstract motivated by the extensive experimental and empirical evidence on preference reversal in consumption choices we introduce temptation with self control preferences into a new keynesian model to study the effects of forward guidance in monetary policy and the related forward guidance puzzle in our set up the representative agent faces a trade off between the temptation for immediate satisfaction liquidate wealth with his long run best smooth consumption which he manages by exerting cognitive effort or self control for higher risk aversion in temptation than in commitment utility there is discounting in the linearized euler equation the latter makes the response of current real activity to the announcement of a future policy change declining in the forward guidance horizon which then helps solving the puzzle our framework delivers testable aggregate and policy implications that distinguish it from alternative microfoundations for discounting in the euler equation previously used to solve the puzzle

consumption savings decisions with quasi geometric discounting we study the consumption savings problem of an infinitely lived rational consumer who has time inconsistent preferences in the form of quasi geometric discounting the consumer operates a weakly concave production function and must simply divide current resources into current consumption and savings there is no uncertainty a solution to the consumer s problem is a subgame perfect equilibrium of a dynamic game between the consumer s successive selves we show that this game has a continuum of equilibria in stationary markov strategies not only is the stationary point of the consumer s asset holdings indeterminate but each stationary point has a continuum of dynamic paths converging to it the savings policy rules underlying these dynamic paths are step functions

central bank forex internvention assessed in continous time abstract this paper looks at some of the principal characteristics of foreign exchange intervention by central banks the approach is novel in that virtually continous time data have been exploited using reuters screen information jel f31

fiscal rules and discretion under persistent shocks this paper studies the optimal level of discretion in policymaking we consider a fiscal policy model where the government has time inconsistent preferences with a present bias toward public spending the government chooses a fiscal rule to trade off its desire to commit to not overspend against its desire to have flexibility to react to privately observed shocks to the value of spending we analyze the optimal fiscal rule when the shocks are persistent unlike under independent and identically distributed shocks we show that the ex ante optimal rule is not sequentially optimal as it provides dynamic incentives the ex ante optimal rule exhibits history dependence with high shocks leading to an erosion of future fiscal discipline compared to low shocks which lead to the reinstatement of discipline the implied policy distortions oscillate over time given a sequence of high shocks and can force the government to accumulate maximal debt and become immiserated in the long run

a new approach to the effect of intervention frequency on the foreign exchange market evidence from japan this article estimates and analyses the effect of intervention frequency on the yen dollar market using daily intervention data we examine using a nonlinear methodology with the frequency of intervention from april 1991 to december 2005 as a focal explanatory variable in this article we also introduce a flexible target zone model that is capable of characterizing the dynamic behaviour of an exchange rate implied by the original target zone model of krugman and its modifications the empirical results show the importance of considering the threshold effect when analysing the effect of intervention due to the presence of asymmetry in the foreign exchange market moreover we show that a high frequency intervention stabilizes the exchange rate by reducing exchange rate volatility especially when the yen appreciates

the market microstructure of central bank intervention abstract how quickly do central bank intervention operations impact the foreign exchange market and do intra daily market conditions influence the effectiveness of central bank interventions this paper uses high frequency intra daily data to examine the relationship between the efficacy of intervention operations and the state of the market at the moment that the operation is made public the results indicate that some traders typically know that the fed is intervening at least 1 h prior to the public release of the information in newswire reports also the evidence suggests that the timing of intervention operations matters interventions that occur during heavy trading volume that are closely timed to scheduled macro announcements and that are coordinated with another central bank are the most likely to have large effects

central bank intervention and exchange rate volatility abstract this paper explores the effects of foreign exchange intervention by central banks on the behavior of exchange rates the g 3 central banks have undertaken an unprecedented number of both coordinated and unilateral intervention operations in the last 10 years existing empirical evidence on the effectiveness of intervention is mixed studies using data from the 1970s suggest that intervention operations that do not affect the monetary base have at most a short lived influence on exchange rates but more recent studies indicate that the intervention operations that followed the plaza agreement influenced both the level and variance of exchange rates this paper examines the effects of us german and japanese monetary and intervention policies on dollar mark and dollar yen exchange rate volatility over the 1977 1994 period the results indicate that intervention operations generally increase exchange rate volatility this is particularly true of secret interventions which are those undertaken by central banks without notification of the public overt interventions in the mid 1980s appear to have reduced exchange rate volatility but in other periods and for the 1977 1994 period as a whole central bank intervention is associated with greater exchange rate volatility

pv sector in the european union countries clusters and efficiency abstract european union eu due to several challenges that exist nowadays has changed its energy policy in order to fulfill international commitments concerning greenhouse gas emission and to assure safety in supply and stable prices eu has been a leader in renewable energy in many eu countries solar energy is a possible and very viable option together with wind energy photovoltaic energy is the new support core of a low carbon eu economy in what concerns electricity production in this work clusters of countries were generated based on the energy produced by pv systems and the share of energy from pv systems in the total electricity produced by renewable sources this work also analyzed the production of energy from the photovoltaic sector in eu and compared it with the existing potential for this type of energy roughly half of the eu countries are producing energy within the limits of what is expected considering the irradiation on optimally inclined plane however some of them could improve the ratio between energy production and installed power considering the leader countries in energy production from photovoltaic czech republic and spain are the countries that exceed what it is expected

self control and the theory of consumption to study the behavior of agents who are susceptible to temptation in infinite horizon consumption problems under uncertainty we define and characterize dynamic self control dsc preferences dsc preferences are recursive and separable in economies with dsc agents equilibria exist but may be inefficient in such equilibria steady state consumption is independent of initial endowments and increases in self control increasing the preference for commitment while keeping self control constant increases the equity premium removing nonbinding constraints changes equilibrium allocations and prices debt contracts can be sustained even if the only feasible punishment for default is the termination of the contract

does foreign exchange intervention matter the portfolio effect until recently there was an unusual degree of consensus among economists that intervention by central banks in the foreign exchange market did not offer an effective or lasting instrument for affecting the exchange rate at least not independently of monetary policy this consensus was largely shared among policymakers and participants in the financial markets as well the 1982 g 7 economic summit at versailles commissioned a study of intervention known as the jurgenson report which found that the effects were small and transitory at most we think that the time is ripe for new statistical testing of the question many policymakers and foreign exchange traders believe that the intervention operations that have taken place since the plaza agreement of september 1985 have had an effect especially when operations are coordinated moreover the theoretical case against the effectiveness of intervention is not as clear as a reading of the economics literature might suggest the academic literature is predicated on the distinction between intervention operations that are sterilized and those that are allowed to affect the money supply we study the intervention operations that actually took place between 1982 and 1988 regardless of whether they were sterilized however we do begin in section i with a review of the issues involved 2 there are two possible channels through which intervention whether sterilized or not can influence the foreign exchange rate the portfolio and the expectations channels intervention can even if sterilized influence exchange rates through the portfolio channel provided foreign and domestic bonds are considered imperfect substitutes in investors portfolios intervention operations that for example increase the current relative supply of mark to dollar assets which private investors are obliged to accept into their portfolios will force a decrease in the relative price of mark assets 3 intervention can also influence exchange rates regardless of whether foreign and domestic bonds are imperfect substitutes through the expectations channel the public information that central banks are intervening in support of a currency or are planning to intervene in the future may under certain conditions cause speculators to expect an increase in the price of that currency in the future speculators react to this information by buying the currency today bringing about the change in the exchange rate today in sections ii and iii we describe the econometric problems that arise in the standard portfolio balance estimation equation we derive an alternative portfolio balance dominguez kennedy school of government harvard university 79 j f kennedy street cambridge ma 02138 frankel department of economics university of california 787 evans hall berkeley ca 94720 we thank three anonymous referees for valuable comments and suggestions julia marsh and julia lowell for research assistance and franz scholl at the bundesbank jean pierre roth at the swiss national bank and officials at the u s treasury and the board of governors of the federal reserve system for making the daily intervention data available 1many of the econometric results finding little or no effect were reported in kenneth s rogoff 1984 and dale w henderson and stephanie sampson 1983 2for authoritative statements see henderson 1984 or maurice obstfeld 1990 3the exchange rate reaction to an increase in the relative supply of outside foreign assets may be reduced if there is an increase in their expected rate of return that induces a corresponding increase in demand

on the effects of sterilized intervention an analysis of weekly data abstract as the recent empirical studies surveyed here illustrate it is very difficult to demonstrate that the exchange rate risk premium depends through a portfolio balance channel on the currency composition of outside assets the existence of a portfolio balance effect is a necessary condition for sterilized intervention to be a genuinely independent tool of monetary policy this paper studies u s canadian data and attempts to improve on earlier studies by using higher frequency weekly data and by implementing an appropriate instrumental variables technique 2s2sls however we still fail to detect evidence of a portfolio balance effect

ramsey meets laibson in the neoclassical growth model the neoclassical growth model is modified to include a variable rate of time preference with no commitment ability and log utility the equilibrium features a constant effective rate of time preference and is observationally equivalent to the standard model the extended framework yields testable linkages between the extent of commitment ability and the rates of saving and growth the model also has welfare implications including the optimal design of institutions that facilitate household commitments steady state results are obtained for general concave utility functions and some properties of the transitional dynamics are characterized for isoelastic utility

nonlinear pricing with self control preferences a basic assumption of economics is that consumers choose what they want however many consumers find it difficult to stop overeating overspending smoking procrastinating etc even though they want to in reality consumers have temptation and it is psychologically costly to exercise self control to clarify the implications of the existence of temptation and self control costs this paper studies a firm s optimal selling strategy exploiting the behavioral features of consumers we characterize optimal nonlinear pricing schemes for a monopoly when self control is costly for consumers since consumers have a preference for commitment the firm faces a trade off between offering a small menu that makes the consumers self control easier and offering a large menu that achieves better price discrimination we show that the optimal menu resembles the one in the standard nonlinear pricing problem with a price ceiling where the upper bound on prices is determined endogenously by a participation constraint the ceiling motivates the firm to offer a relatively flat and compact price schedule serving more consumers with low demand the characterization also shows that the firm may earn less if consumers have temptation

evaluating foreign exchange market intervention self selection counterfactuals and average treatment effects abstract estimating the effect of official foreign exchange market intervention is complicated by the fact that intervention at any point entails a self selection choice made by the authorities and that no counterfactual is observed to address these issues we estimate the counterfactual exchange rate movement in the absence of intervention by introducing the method of propensity score matching to estimate the average treatment effect ate of intervention to derive the propensity scores we estimate central bank intervention reaction functions we estimate the ate for daily official intervention in japan over the january 1999 march 2004 period this sample encompasses a remarkable variation in intervention frequencies as well as unprecedented frequent intervention towards the latter part of the period we find that only sporadic and relatively infrequent intervention is effective

optimal taxation of capital income in general equilibrium with infinite lives this paper analyzes the optimal tax on capital income in general equilibrium models of the second best agents have infinite lives and utility functions which are extensions from the koopmans form the population is heterogeneous the important property of the models is the equality between the social and the private discount rates in the long run i find that the optimal tax rate is zero in the long run for a special case of additively separable utility functions i then determine the tax rates along the dynamic path and conditions that are sufficient for the local stability of the steady state

loss aversion in politics we study how loss aversion affects the political equilibrium in a simple majority voting model first we show a status quo bias which leads to path dependence second loss aversion implies a moderating effect on the most extreme voters third in a dynamic setting the effect of loss aversion diminishes with the length of the planning horizon of voters however in the presence of a projection bias majorities are partially unable to understand how fast they will adapt to a new policy this makes changes less likely and induces time inconsistency policy changes are timid at the beginning while in later periods they are made progressively more radical fourth in a stochastic environment loss aversion yields a significant distaste for risk but also a smaller attachment to the status quo the application of these results to a model of redistribution leads to empirically plausible implications

optimal tax rules and addictive consumption abstract this paper studies implementation of the social optimum in a model of addictive consumption we consider corrective taxes that address inefficiencies due to negative externalities imperfect competition and self control problems our setup allows us to evaluate how such taxes are affected by i market power and ii a requirement for implementation to be time consistent together these features can imply significantly lower taxes we provide a general characterization of the optimal tax rule and illustrate it with two examples

the main support mechanisms to finance renewable energy development considering that the major part of greenhouse gases is carbon dioxide there is a global concern aimed at reducing carbon emissions additionally major consumer countries are looking for alternati

advanced solar r d combining economic analysis with expert elicitations to inform climate policy the relationship between r d investments and technical change is inherently uncertain in this paper we combine economics and decision analysis to incorporate the uncertainty of technical change into climate change policy analysis we present the results of an expert elicitation on the prospects for technical change in advanced solar photovoltaics we then use the results of the expert elicitations as inputs to the minicam integrated assessment model to derive probabilistic information about the impacts of r d investments on the costs of emissions abatement

economic analysis of the contribution of photovoltaics to the decarbonization of the power sector abstract an analytical method has been developed for the calculation of the future 2013 2050 reduction of co2 emissions by the deployment of photovoltaic pv systems according to three scenarios from the international energy agency 2ds roadmap and new policies next we have also evaluated the financial extra costs incurred in the implementation of the pv systems which would replace the current traditional power generation systems taking as reference four geographical areas european union united states china and the world s average the established method also allows the comparison of the influence on the extra costs of the actual electricity mix as well as the current electricity prices corresponding to the above regional areas in these calculations we have taken into account several frequently ignored factors like solar cell degradation emissions attributed to the pv systems life cycle and the repowering due to the substitution of the systems after their life time is reached finally the results of this work can be of interest in energy planning policies related to the contribution of pv technologies for the decarbonization of the power generation system

voting as a lottery supermajorities have their advantage as well as their disadvantage they provide an hedge against being in the minority but they make being in the majority less likely we characterize this trade oand compute the most preferred majority threshold the relevant parameters are voting power risk aversion and pessimism people who feel powerful prefer low thresholds high thresholds are preferred by risk averters or by those who are pessimistic about being in the majority further we study constitutional agreements on the voting rule members of the constituent assembly are heterogeneous in the parameters above we show that weak and minority members succeed in pushing forward on high and protective rules

unraveling the photovoltaic technology learning curve by incorporation of input price changes and scale effects in a large number of energy models the use of learning curves for estimating technological improvements has become popular this is based on the assumption that technological development can be monitored by following cost development as a function of market size however recent data show that in some stages of photovoltaic technology pv production the market price of pv modules stabilizes even though the cumulative capacity increases this implies that no technological improvement takes place in these periods the cost predicted by the learning curve in the pv study is lower than the market one we propose that this bias results from ignoring the effects of input prices and scale effects and that incorporating the input prices and scale effects into the learning curve theory is an important issue in making cost predictions more reliable in this paper a methodology is described to incorporate the scale and input prices effect as the additional variables into the one factor learning curve which leads to the definition of the multi factor learning curve this multi factor learning curve is not only derived from economic theories but also supported by an empirical study the results clearly show that input prices and scale effects are to be included and that although market prices are stabilizing learning is still taking place

political economy of mechanisms we study the optimal mirrlees taxation problem in a dynamic economy in contrast to the standard approach where the taxation mechanism is operated by a benevolent planner with full commitment power we focus on economies in which policy decisions are made by self interested politicians who cannot commit to policies the society controls politicians using elections we show that the provision of incentives to politicians can be partly separated from redistribution across agents and that political economy constraints can be modeled as introducing additional aggregate distortions in the dynamic mirrlees problem we provide conditions under which the political economy distortions persist or disappear in the long run if the politicians are as patient as the agents the best sustainable mechanism leads to an asymptotic allocation where the aggregate distortions arising from political economy disappear in contrast when politicians are less patient than the citizens positive aggregate labor and capital taxes remain even asymptotically we conclude by providing a brief comparison of centralized

temptation driven behavior and taxation a quantitative analysis in a life cycle model i introduction a central research question in the dynamic fiscal policy literature during the last 30 years or so is whether under fairly general modeling choices the government should impose a positive tax on capital income in the long run the original answer to this question is negative and is due to the seminal papers by chamley 1986 and judd 1985 who established that in the context of a standard neoclassical growth model with infinitely lived individuals an optimal income tax policy entails taxing capital at confiscatory rates in the short run and setting capital income taxes equal to zero in the long run only labor income should be taxed in the long run since then several modeling choices that cast doubt on the validity of this result were identified in the literature imrohoroglu 1998 showed that the optimal capital income tax rate is strictly positive in an overlapping generations olg setting where individuals face idiosyncratic earnings risk borrowing constraints and life span uncertainty conesa kitao and krueger 2009 extended imrohoroglu 1998 by adding a labor leisure choice they demonstrated that the optimal capital income tax rate is equal to 36 and concluded that this high rate is mainly driven by the life cycle structure of the model in contrast krusell kuruscu and smith 2010 analytically showed that within a class of ramsey tax schemes the optimal capital income tax rate should be negative that is savings should be subsidized when agents have self control problems moreover in the special case where consumers succumb completely to temptation ramsey taxes deliver first best welfare outcomes and in contrast to the chamley judd result the optimum calls for a subsidy to savings however an integrated assessment of the combined effects of the relevant trade offs both along the dimension of differences in preferences and along the dimension of the scope of capital income taxation versus labor income taxation is missing from all previous studies in both social security and capital taxation literature and this paper aims to bridge the gap in the literature and contribute in this aspect to the best of our knowledge this paper is the first study that introduces temptation driven preferences in a quantitative model aiming to tackle the question on the optimal capital income tax before proceeding to specifically articulate this paper s contribution to the literature we consider critical to address a question that lies at the very core of our line of research namely why fiscal policy models with time inconsistent or self control preferences are relevant in the first place initially the literature pioneered by strotz 1956 and phelps and poliak 1968 corroborated evidence coming from both introspection and experiments that agents exhibit preference reversals as time passes different strands within this literature have suggested that these preference reversals could be induced by either time inconsistent preferences see laibson 1997 or self control preferences gul and pesendorfer 2004 time inconsistent preferences typically assume that agents have sequences of different selves each valuing consumption streams in a unique way in contrast gul and pesendorfer 2004 provide a dynamically consistent model suitable for addressing preference reversals that does not necessitate splitting up the consumer in multiple selves that is self control preferences these preferences describe an individual that in every period is tempted to consume his entire endowment when he consumes less than his endowment he incurs a disutility cost that stems from exercising self control that is self control cost optimal behavior trades off the temptation to consume vis a vis the long run self interest of the individual 1 alongside these theoretical underpinnings there is sound empirical and experimental evidence that agents suffer from self control problems