black market exchange rate and the productivity bias hypothesis abstract previous studies that tested the productivity bias hypothesis employed the official nominal exchange rate in constructing the real rate hence in testing the productivity bias hypothesis in this paper we show that if official real exchange rate does not support the productivity bias hypothesis the real black market rate does this conjecture is tested by using data from chile colombia and costa rica

instability in short run adjustments to purchasing power parity results for selected latin american countries according to the theory of purchasing power parity ppp there is a tendency toward equalization of different countries price levels in common currency terms however even assuming that a long run ppp relationship exists its relevance for policy makers in less developed countries ldcs will depend not only on the average speed of adjustment toward this relationship but also on the variability of such short run adjustments we present evidence of extreme volatility in adjustments toward ppp for four latin american countries based on time varying parameter estimates of error correction models

de gustibus non est taxandum heterogeneity in preferences and optimal redistribution abstract the prominent but unproven intuition that preference heterogeneity reduces redistribution in a standard optimal tax model is shown to hold under the plausible condition that the distribution of preferences for consumption relative to leisure rises in terms of first order stochastic dominance with income given familiar functional form assumptions on utility and the distributions of ability and preferences a simple statistic for the effect of preference heterogeneity on marginal tax rates is derived numerical simulations and suggestive empirical evidence demonstrate the link between this potentially measurable statistic and the quantitative implications of preference heterogeneity for policy

optimality of workfare with heterogeneous preferences with the standard non linear income taxation framework with heterogeneity of preferences in this paper the optimality of workfare as a screening tool is examined it is assumed that workfare does not serve as a human capital investment participation is mandatory and administrative costs are negligible imposing alternative cardinalizations on individuals utilities allows for the possibility that the government optimally redistributes income to or from high disutility of labour individuals under either case it is never optimal to impose workfare on these individuals it is also shown that non productive workfare can be an e cient policy tool in contrast to the results found in besley and coate 1995 brett 1998 and beaudry and blackorby 1997 jel classification h21 h23 optimalite du workfare en presence de preferences heterogenes l auteur examine l timalite du workfare en tant qu instrument de tamisage a l aide du cadre conceptuel traditionnel d imposition non lineaire des revenus en presence de preferences heterogenes on postule que le workfare n est pas un processus d investissement en capital humain que la participatioun est obligatoire et que les couts d administration sont negligeables quand on postule aussi des utilites cardinales differentes pour les individus il devient possible pour le gouvernement de redistribuer optimalement les revenus en faveur ou au detriment des individus pour qui le travail a une tres grande desutilite dans l un et l autre cas on montre que le workfare n est jamais une politique optimale on montre aussi que le workfare dans des activites non productives peut etre un instrument de politique publique e cient contrairement a ce qu a rment besley et coate 1995 brett 1998 et beaudry et blackorby 1997

excess volatility of real exchange rates in the ems some evidence from structural vars this paper argues that the effectiveness of the exchange rate mechanism erm of the european monetary system ems should be gauged by its impact on the monetary component of real exchange rate variability nominal and real shocks are separated using a bivariate structural var applied to real exchange rate data of the six original member countries participating in the erm and a control group consisting of britain and the united states the findings suggest that monetary shocks have been an important source of real exchange rate variability and that the erm has been successful in reducing the incidence of monetary shocks across its member countries prior to the ems currency crises of 1992 93 while being less successful thereafter

a reexamination of balassa s productivity bias hypothesis rency by ri s the price level in country i by pi and the price level in the united states by pu s the ppp theory postulates that ri u s pi pu s many studies have tried to verify whether exchange rates follow the path outlined by the ppp equation the empirical results at best are inconclusive for example j a frenkel tested the ppp by drawing data from the 1970s and showed that the ppp failed on the other hand n davutyan and j pippenger criticized frenkel s work and reversed his conclusion 2 both studies used ordinary least squares and two stage least squares methods even recent studies that have used a relatively modern econometric technique cointegration analysis have mostly rejected the ppp 3 several reasons have been given in the literature for the failure of the ppp or deviation of the ppp based exchange rates from equilibrium exchange rates including lack of free trade existence of transaction costs existence of nontradables simultaneity problems different weights used in constructing different national price indexes money and asset prices and real factors or real variables among the real variables the productivity differential between two countries has received most of the attention in the literature if we denote the market determined equilibrium exchange rate by re and the ppp based rate by pi pu s following the literature we

income maintenance and labor force participation the paper studies the optimal tax subsidy schedules in an economy where the only decision of the agents is to work or not with an application to the case of france given an income guarantee provided by the welfare state the tax schedule that maximizes government revenue provides a benchmark the laffer bound above which it is inefficient to tax in fact under mild conditions a feasible allocation is second best optimal if and only if the associated taxes are lower than the laffer bound the only restriction that efficiency puts on the shape of the tax scheme is this upper laffer bound the laffer tax scheme itself can be computed from the joint distribution of the agents productivities and work opportunity costs depending on the economy it can take widely different forms and exhibit for instance negative marginal tax rates after estimating the joint distribution of productivities and work opportunity costs on french data i compute the laffer bound for two subpopulations single women and married women with two children or more quite surprisingly the actual incentives to work appear to be very close to the bound

monopoly provision of product quality and warranties an exploration in the theory of multi dimensional screening we address the monopoly problem of designing and pricing a product line of goods distinguished by different quality and warranty levels consumers vary in their evaluations of these attributes so that the problem is one of screening it is sufficiently complex that the local approach commonly used does not work instead we use new techniques for dealing with incentive constraints between nonadjacent consumer types these techniques allow us to characterize optimal allocations that may not be monotonic in particular although the more eager types of buyer do pay higher prices and yield the monopoly higher profit they may receive lower quality or lower warranty coverage we find preference restrictions that restore monotonicity concave risk tolerance implies that warranty coverage increases in type and constant absolute risk aversion implies that quality increases in type

agency and the design of welfare systems abstract transfers to the needy are administered by social workers whose job it is to tag welfare applicants to determine eligibility for disability benefits the accuracy of tagging depends on the effort of the social workers which is private information to prevent shirking and induce optimal effort costly monitoring is required using the framework of optimal non linear taxation we characterize the form of the optimal tax transfer system when the government operates a costly welfare system financed by income taxation higher income persons self select into the income tax system the needy apply for welfare if tagged they receive a disability benefit if untagged they receive general welfare benefits we characterize circumstances under which welfare recipients should or should not be induced to work the structure of the optimal tax transfer system and the optimal payment and monitoring of social workers

optimal redistribution when different workers are indistinguishable using the standard non linear income and commodity taxation framework this paper examines the optimal policy to be adopted when the same labor disutility can receive two opposite interpretations taste for leisure and activity limitation in the absence of complete information about individual characteristics an income tax does not allow to distinguish lazy from handicapped individuals one may however rely on a combination of commodity and income taxes to redistribute from the former to the latter when they differ in their preferences for commodities

optimal incentives for labor force participation abstract optimal taxation is analyzed under a rawlsian criterion in an economy where the only decision of the agents is to participate or not to the labor force the model allows for heterogeneity both in the agent s productivities and aversions to work at a first best optimal schedule the marginal agent who decides to work pockets all of her productivity while being just compensated for her work aversion when the planner does not observe work aversion financial compensation for work is lower than productivity theory puts little restrictions on the shape of the optimal tax schedules the usual first order conditions involving the elasticities of participation only apply for sufficiently regular economies we qualitatively show how the optimal incentive schemes depend on the underlying structure of the preferences 100 marginal tax rates or subsidies to work are related to specific features of the economies

viewpoint innovations in the theory and practice of redistribution policy we present a survey of key results from second best optimal redistribution theory and their implications for tax transfer policy the core results include the corlett hague theorem the deaton conditions the production efficiency theorem the atkinson stiglitz theorem and the mirrlees saez characterization of the optimal non linear income tax system these have been augmented in recent years by optimal participation tax rates the implications of involuntary unemployment the use of unconventional instruments such as minimum wages in kind transfer and workfare and the optimal taxation of capital income and bequests l auteur presente un survol des principaux resultats theoriques de la redistribution optimale de second ordre et de leurs implications pour les politiques d imposition et de transferts les resultats fondamentaux incluent le theoreme de corlett hague les conditions de deaton les theoremes d efficacite en production le theoreme d atkinson stiglitz ainsi que la caracterisation du systeme optimal d imposition non lineaire du revenu a la mirrlees saez ces derniers resultats ont ete enrichis au cours des dernieres annees par certains autres portant sur les taux d imposition decoulant des allocations conditionnelles les implications du chomage involontaire l usage d instruments non conventionnels tels que le salaire minimum les transferts en nature le workfare ainsi que l imposition optimale des revenus du capital et des legs ces resultats sont exposes et leurs implications pour les politiques d imposition et de transferts sont discutees

why real interest rates cost of capital and price earnings ratios vary across countries abstract this paper examines how productivity changes affect real rates of return and price earnings ratios in a small open economy the model provides conditions under which increased productivity in a country s traded goods sector causes prices of non traded goods to increase relative to the price of traded goods under these conditions real rates of interest decline and the production of certain non traded durable goods such as capital equipment and housing immediately increase this overconstruction has two effects first the increase in capital relative to labor in these sectors increases the marginal product of labor and hence immediately causes an increase in wages and the prices of non traded goods second an oversupply of capital goods and housing depresses their rental rates in the current period thereby increasing their price to rental ratios or equivalently their price earnings ratios

welfare work requirements with paternalistic government preferences work requirements in means tested transfer programmes have grown in importance in the us and in some other countries the theoretical literature which considers their possible optimality generally operates within a traditional welfarist framework where some function of the utility of the poor is maximised here we consider a case where society instead has preferences over the actual work allocations of welfare recipients optimality of work requirements is shown to be possible but depends on the accuracy of the screening mechanism which assigns work requirements numerical simulations show that accuracy must be high for optimality earnings subsidies may also be optimal work requirements in means tested or welfare programmes have seen a resurgence in the last twenty years in the us and in a few european countries these requirements generally stipulate that benefit recipients must work or engage in some work like activity for some minimum number of hours each week most economists who have studied the

taxes and employment subsidies in optimal redistribution programs this paper explores how to optimally set taxes and transfers when taxation authorities 1 are uninformed about individuals value of time in both market and non market activities and 2 can observe both market income and time allocated to market employment we show that optimal redistribution in this environment involves distorting market employment upwards for low wage individuals through decreasing wage contingent employment subsidies and distorting employment downwards for high wage individuals through positive and increasing marginal income tax rates in particular we show that whether a person is taxed or subsidized depends primarily on his wage with the optimal program involving a cut off wage whereby workers above the cutoff are taxed as they increase their income while workers earning a wage below the cutoff receive an income supplement as they increase their income finally we show that the optimal program transfers zero income to individuals who choose not to work

minimum wage legislation and unemployment insurance as instruments for redistribution the use of minimum wages and unemployment insurance as instruments for redistributing income is analyzed the government is assumed to be able to implement an optimal income tax in an economy consisting of two types of individuals who differ in ability the effect of introducing a minimum wage which induces involuntary unemployment will be to improve social welfare under weak conditions circumstances under which combining unemployment insurance with the minimum wage will be welfare improving are also considered

a quantitative reassessment of the purchasing power parity hypothesis evidence from norway and the united kingdom summary annual data from norway and the united kingdom from 1874 to 1971 are used to reassess the empirical performance of the purchasing power parity ppp doctrine the simple version of the ppp relationship is supported by the data only if different short run dynamics during a floating rate period 1914 1928 is allowed for two sets of factors were found to be important in amending the simple ppp model these were short run cyclical variables affecting the adjustment towards the ppp equilibrium relationship and long run structural factors such as productivity and terms of trade within this expanded model the proportionality between the exchange rate and relative price levels could not be rejected

the optimal taxation of unskilled labor with job search and social assistance abstract in order to explore the optimal taxation of low skilled labor we extend the standard model of optimal nonlinear income taxation in the presence of quasi linear preferences in leisure by allowing for involuntary unemployment job search and an exogenous welfare benefit in trading off low skilled employment against work effort of higher skilled workers the government balances distortions on the search margin with those on work effort higher welfare benefits typically reduce taxes paid by low skilled workers and raise marginal tax rates throughout the skill distribution

a note on the determinants of unexpected exchange rate movements abstract in this paper we study the relative importance of surprises in fundamentals in explaining unexpected exchange rate movements employing a unique survey dataset that contains matched exchange rate and interest rate expectations we are able to derive a number of interesting conclusions a variance decomposition of unexpected exchange rate movements into various components reveals that interest rate news is relatively unimportant but that changes in perceptions about risk premia and more importantly revisions of expectations with regard to future exchange rate levels are crucial in explaining unexpected exchange rate movements

productivity differentials the relative price of non tradables and real exchange rates abstract this paper reconciles the apparent contradiction between recent panel unit root tests of real exchange rates and the productivity differential model proposing an alternative view that explains the coexistence of such findings real exchange rates and the relative price of non tradables reflect the gradual adjustment of mean reverting and endogenously competing factors supply and demand shocks as well as traded goods arbitrage granger causality and variance decomposition results indicate substantial simultaneity and feedback effects between real exchange rates the relative price of non tradables and productivity differentials

does foreign aid promote the expansion of government building on the literature on public finance i seek to advance our understanding of variations in government size by exploring the impact of official development assistance on fiscal policy i hypothesize that foreign aid operates in accordance with the flypaper effect systematically generating incentives and opportunities for the expansion of government spending results from a time series cross sectional regression analysis of growth in government spending over the 1970 99 time period are consistent with the hypothesis for middle and lower income nations aid represents an important determinant of government expansion looking at the tax and revenue side of the equation however reveals a more perverse pattern of response aid promotes not only increased spending but also reduced revenue generation the results have important implications from both a theoretical and policy perspective inter alia they point to the potentially self defeating nature of efforts to promote market oriented programs of state retrenchment via development assistance as well as to the importance of incorporating international transfers into future research on government spending

sources of fluctuations in real and nominal exchange rates this paper attempts to distinguish empirically real versus nominal sources of fluctuations in real and nominal exchange rates the distinction is obtained by imposing the following restriction on the bivariate vector autoregression of real and nominal exchange rates over the current flexible rate period nominal shocks are required to have no permanent effect on the level of the real exchange rate given this identification scheme the author analyzes the dynamic effects and relative importance of real and nominal shocks with regards to exchange rates the findings indicate that real shocks dominate nominal shocks for both exchange rate series over short and long frequencies copyright 1992 by mit press

productivity bias hypothesis and the purchasing power parity a review article abstract productivity differentials among countries are said to be one of the major sources that contribute to the deviation of the purchasing power parity based exchange rate from the equilibrium rate hence the productivity bias hypothesis prior to last review article on the productivity bias hypothesis in 1976 almost all studies relied upon cross sectional regression analysis since then two groups of empirical studies have emerged while one group has employed time series data the other one has used panel data these two later groups have provided more support to the hypothesis than the earlier cross sectional studies this paper reviews and criticizes each group separately and provides tables that summarize main features of each study

supply side hysteresis the case of the canadian unemployment insurance system abstract this paper presents results from a 1971 natural experiment carried out by the canadian government on the unemployment insurance system at that time the generosity of the ui system was increased dramatically we find some evidence that the propensity to collect ui increases with a first time exposure to the new ui system hence as more individuals experience unemployment their lifetime use of the system increases this supply side hysteresis effect may explain why unemployment has steadily increased over the 1972 1992 period even though the generosity of unemployment insurance did not

optimal non linear income taxation for the alleviation of income poverty there has been much discussion recently of structuring tax and transfer programs to ensure that resources go to the poor with minimal leaks to the nonpoor the poor have no incentive to earn income with 100 percent marginal tax rates but how high or low the marginal rate of taxation should be and how they should vary with income is a complex issue and opinions vary social security schemes that withdraw benefits represent an extremely high effective marginal tax rate other schemes call for relatively low marginal tax rates at the bottom of the income distribution which tax transfer schedule does most to reduce poverty the issue is one of optimal nonlinear income taxation the authors show that one of the key theoretical results of the welfarist literature is overturned if it is desirable for everybody to work the optimal marginal tax rate on the very poorest individuals is strictly negative they argue that the nonwelfarist perspective points toward lower marginal tax rates in the lower part of the income distribution than does the welfarist perspective but numerical simulations suggest that the effect is of limited quantitative significance using conventional functional forms and parameter values optimal marginal tax rates on the poor are in the 60 70 percent range

oil prices and financial stress a volatility spillover analysis this paper examines whether there is a volatility transmission between oil prices and financial stress by means of the volatility spillover test we employ wti crude oil prices and cleveland financial stress index for the period 1991 2014 and divide the sample into pre crisis in crisis and post crisis periods due to the downward trend in oil price in 2008 the volatility model estimations indicate that oil prices and financial stress index are dominated by long run volatility the volatility spillover causality test supports evidence on risk transfer from oil prices to financial stress before the crisis and from financial stress to oil prices after the crisis the impulse response analysis shows that the volatility transmission pattern has similar dynamics before and after the crisis and is characterized by higher and long lived effects during the crisis our results have implications for both policy makers and investors and for future work

unemployment insurance and job durations seasonal and non seasonal jobs the authors use regional and individual variation in unemployment insurance ui parameters to estimate the impact of ui incentives on job durations in doing so they distinguish between seasonal and nonseasonal jobs the authors find evidence of substantial tailoring of job durations to ui incentives in seasonal but not in nonseasonal jobs even for seasonal jobs adjusting ui parameters has small impacts on average job duration except in high unemployment regions increasing the ui entrance requirement leads to some job lengthening but also to the creation of more very short jobs

a reduced form optimal nonlinear income tax problem abstract for a finite population with quasilinear preferences it is shown how mirrlees optimal nonlinear income tax problem can be simplified to a reduced form problem involving only the allocation of the consumption good this result is a finite version of a proposition established in the continuum by s lollivier and j c rochet

participation constraints in adverse selection models abstract this paper characterizes the optimal contract offered by an uninformed principal to an informed agent when the latter s reservation utility depends on his type the informational rent is nonmonotonic so that interior types may have a vanishing rent or be excluded from trade the paper identifies conditions for the optimal contract to be separating to be nonstochastic and to induce full participation it also discusses the nature of the solution when bunching occurs the results are applied to nonlinear pricing under price cap regulation and bypass competition and to competition in nonlinear pricing journal of economic literature classification numbers d82 d42 d23 d78 l51 l15

optimal redistribution a life cycle perspective abstract in this paper i characterize the optimal redistribution policy in a simple life cycle framework with both an intensive and an extensive margin of labor supply the extensive margin corresponds to the choice of a retirement age the optimal allocation cannot be implemented in a decentralized economy by a standard non linear income tax alone it can however be implemented by a history dependent social security system which redistributes resources across agents a calibration of the model to the u s economy reveals that the retirement age should optimally be sharply increasing in productivity and that implementing the optimal life cycle redistribution policy can generate large social welfare gains

an empirical inquiry into the nature of the forward exchange rate bias abstract this paper tests whether anticipated real exchange rate movements fully account for the systematic time varying discrepancies between forward and future spot exchange rates the data do not reject this hypothesis the results demonstrate that 1 real exchange rate changes are predictable 2 anticipated real exchange rate changes are reflected in the forward bias and 3 information available at the signing of the forward contract is useless in forecasting differences between forward and future spot prices beyond the information s ability to predict real exchange rate changes the results emphasize the importance of real exchange rates in international asset pricing

optimum income taxation and layoff taxes this paper analyzes optimum income taxation in a model with endogenous job destruction that gives rise to unemployment it is shown that optimal tax schemes comprise both payroll and layoff taxes when the state provides public unemployment insurance and aims at redistributing income the optimal layoff tax is equal to the social cost of job destruction which amounts to the sum of unemployment benefits that the state pays to unemployed workers and payroll taxes that the state does not get when workers are unemployed

a comparison of tax bases for a personal tax tax bases for a personal tax are compared in this paper it is found that the potential welfare gains of moving from a linear affine tax on labor earnings to a linear affine tax on wage rates seem to be larger than the potential gains of moving from a head tax to an earnings tax it is also shown that for the common optimal taxation model utility levels and ability as measured by wage rates are inversely related at the first best optimum a development of the model so that a positive relationship between utility and ability results is suggested

optimal taxation in the extensive model abstract we study optimal taxation under extensive preferences the agents utilities are constant for positive actions up to a maximal productivity level utilities may be discontinuous at the origin reflecting fixed costs of participation allowing for general distributions of work opportunity costs and productivity and for income effects we characterize optimal incentive compatible tax schedules we then give sufficient conditions for society to desire redistribution when these conditions hold upward distortions of the financial incentives to work can only occur for low skilled workers such upwards distortions are indeed always present when the fixed participation costs are pecuniary

government and economic growth in the less developed countries an empirical study for 1960 1980 adam smith founded modern economics with a powerful argument that free markets are the best route to prosperity and economic growth his conclusion has been studied and debated by economists ever since including nobel prize winners friedman hayek kuznets lewis myrdal and schultz whatever economists have concluded since world war ii the majority of the less developed countries seem to have opted for extensive government regulation of the private sector and for a large public sector has the large government role slowed or accelerated the growth of ldcs obviously this is an important issue this study looks at government expenditure revenue raising and regulation greater emphasis is put on expenditure because 1 the revenue raised is presumably a function of the level of expenditure and 2 there are few internationally comparable measures of regulation there are virtually no empirical studies of the general impact of government on economic growth an extensive literature search turned up only three papers gemmell analyzed the impact of nonmarket sector growth on various measures of macroeconomic performance for 27 ldcs and developed countries for 1960 and 1970 he drew no general conclusions about the relation between the size of the nonmarket sector and economic growth marsden found a negative relation between tax gdp ratios and economic growth for a cross section of 20 ldcs and developed countries for the 1970 79 period 2 i found a negative relationship between the share of government consumption expenditure in gdp and the growth of per capita gdp for a cross section of 96 ldcs and developed countries over various time periods between 1961 and 1976 3 this paper extends the approach used in my 1983 article

real exchange rates ppp and the relative price of nontraded goods the purchasing power parity hypothesis ppp states that nominal exchange rates move with differences in relative prices between economies the theory has received considerable attention in the economic literature since cassell 6 and is the foundation of many long run theoretical hypotheses in international finance yet its empirical validity remains in question many tests of ppp focus on the stationarity of the real exchange rate the nominal exchange rate adjusted for changes in price levels between economies if domestic and foreign price levels and the nominal exchange rate are integrated then cointegration between these variables implies the existence of both a long run equilibrium relationship and ppp the residual the real exchange rate then follows a stationary process the paper uses the multivariate cointegration methodology of johansen 16 and johansen and juselius 17 18 to examine the source of real exchange rate nonstationarity is the nonstationarity due to shifts in the domestic and foreign price of nontradeables or productivity differentials between traded and nontraded sectors or is the nonstationarity a possible outcome of difficulties in intercountry comparisons of prices movements associated with construction of these price indices most research finds the real exchange rate follows a nonstationary process due to the presence of a unit root 8 12 1 9 19 27 however the existence of a variable trend in the real exchange rate does not imply the absence of a long run relationship between relative prices levels and nominal exchange rates for two reasons first a long run relationship between price levels and nominal exchange rates may exist but not the one for one relationship implicit in the calculation of real exchange rates due to measurement differences in the construction of price indices between economies second ppp violations may occur due to the presence of permanent productivity innovations which affect the relative price of nontradeables if these shocks are not represented by measurable variables a cointegrating relationship will not exist the paper constructs traded and nontraded gdp price indices and productivity rates for 14 oecd economies and tests 1 if the variable trend the nonstationary process in the real exchange rate is due to permanent innovations in relative price of domestic and foreign nontradeables 2 if long run ppp violations are due to permanent movements in the relative price of nontradeables 3 if the nonstationarity in the real exchange rate is due to permanent innovations in domestic and foreign productivity differentials between the traded and nontraded sectors 4 if the variable trend in the relative price of nontradeables is due to permanent innovations in productivity between sectors lastly the paper constructs a cointegrating error correction model

public choice and economic aid a major development in the analysis of government economic policies in the developed countries has been the rise of the public choice school the essence of this approach is the application of the same basic assumptions that are used in the study of consumers and producers to political decision makers in the public choice approach decision makers in the public sector are assumed to be trying to maximize their personal benefits similarly to consumers and firms imputing utility maximizing behavior to public sector decision makers does not automatically lead to the conclusion that they will not act in the general interest rather whether they do or not becomes a question of the system of rewards and constraints they face as adam smith demonstrated for firms self interested parties will act in the general interest if properly constrained and rewarded however the public choice approach does imply that public sector decision makers will act in the general interest only if the constraints and incentives on their behavior make serving the general interest also in their interest it would appear that development economics which is highly concerned with government policies could benefit from the application of the public choice perspective this article attempts to do this with respect to the effectiveness of economic aid in promoting economic growth there is an extensive literature that discusses theoretically the effectiveness of aid and a more modest literature that attempts to estimate empirically the impact of aid on growth the literature was recently surveyed by r riddell he surveys the views of the major proponents and critics of aid marxist critics of aid reject the market and the notion of a neutral state pursuing the general interest there seem to be no studies of aid that adopt the public choice approach which both accepts the efficiencies of the market as an instrument for economic growth and also assumes government officials are utility

optimal income transfer programs intensive versus extensive labor supply responses this paper analyzes optimal income transfers for low incomes labor supply responses are modeled along the intensive margin intensity of work on the job and along the extensive margin participation into the labor force when behavioral responses are concentrated along the intensive margin the optimal transfer program is a classical negative income tax program with a substantial guaranteed income support and a large phasing out tax rate however when behavioral responses are concentrated along the extensive margin the optimal transfer program is similar to the earned income tax credit with negative marginal tax rates at low income levels and a small guaranteed income carefully calibrated numerical simulations are provided

minimum wage legislation as a second best policy mass unemployment is a striking phenomenon of the present economic situation of european market economies although the profession of economists has been criticized for not providing satisfactory cures it has produced a number of different explanations either complementary or contradictory for the occurrence of mass unemployment in this paper we examine the argument that unemployment is the consequence of minimum wage legislation which is socially desirable the observation of current wage legislations suggests that the above argument is broadly at least partly accepted by policy makers curiously enough a defence of this argument meeting the rigorous requirements of modern theory seems to be missing symmetrically attacks against minimum wage legislation often rely upon reasonings of dubious relevance i e the obvious remark that unemployment is a waste with first best efficiency criteria the present paper proposes a second best analysis where second best stems from informational asymmetries which prevent the implementation of lump sum transfers needed for a first best redistribution policy the question under scrutiny can be reformulated in a more precise way as follows does a second best optimal redistribution policy lead to minimum wage legislation and unemployment our elements of answer are gathered in 3 sections in section 2 the principles of the analysis of the desirability of quantity controls and existing results are recalled in section 3 the analysis of section 2 is specified to a simple prototype model for the study of linear income taxation in section 4

purchasing power parities and exchange rates in latin america purchasing power parity ppp studies in recent years have revealed clearly that international comparisons of real income based on exchange rate conversions are very misleading indicators of standards of living there is no question that ppps provide the conceptually appropriate conversions of national accounts statistics from one currency to another and recent studies have shown that ppps deviate substantially from exchange rates 1 stimulated in part by the appearance of new bodies of data economists have recently renewed their interest in theoretical explanations of the long term or structural deviations of ppps from exchange rates the empirical tests of these models have been conducted almost entirely with data from the international comparisons project icp the purpose of the present paper is to test some of these models with a body of data collected by eciel for some latin american countries in 1970 2 this sample can also be combined with the phase 1 1970 sample of the icp to put this empirical study in context i shall first review briefly the theoretical and empirical literature on deviations of exchange rates from absolute ppps then i shall proceed to the empirical procedures and findings

is it legitimate to encourage work sharing a generalization of mirrlees income taxation model is formulated in which qualifications of workers are both endogenous and observable by the government individuals differ by their unobservable abilities which simultaneously affect their disutility of labor and their cost of training in general the optimal tax schedule depends not only on income but also on its components i e wage rate or qualification and labor supply we find conditions under which it is optimal to subsidize lower qualifications or to encourage work sharing

optimal taxation with rent seeking we develop a framework for optimal taxation when agents can earn their income both in traditional activities where private and social products coincide and in rent seeking activities where private returns exceed social returns either because they involve the capture of pre existing rents or because they reduce the returns to traditional work we characterize pareto optimal income taxes that do not condition on how much of an individual s income is earned in each of the two activities these optimal taxes feature an externality corrective term the magnitude of which depends both on the pigouvian correction that would obtain if rent seeking incomes could be perfectly targeted and on the relative impact of rent seeking externalities on the private returns to traditional and to rent seeking activities if rent seeking externalities primarily affect other rent seekers for example the optimal correction lies strictly below the pigouvian correction a calibrated model indicates that the gap between the pigouvian and optimal correction can be quantitatively important our results thus point to a hefty informational requirement for correcting rent seeking externalities through the income tax code

the overvaluation of renminbi undervaluation we evaluate whether the renminbi rmb is misaligned relying upon conventional statistical methods of inference a framework built around the relationship between relative price and relative output levels is used we find that once sampling uncertainty and serial correlation are accounted for there is little statistical evidence that the rmb is undervalued even though the point estimates usually indicate economically significant misalignment the result is robust to various choices of country samples and sample periods as well as to the inclusion of control variables

multiproduct nonlinear pricing typically work on mechanism design has assumed that all private information can be captured in a single scalar variable this paper explores one way in which this assumption can be relaxed in the context of the multiproduct nonlinear pricing problem it is shown that the firm will choose to exclude some low value consumers from all markets a class of cases that allow explicit solution is derived by making use of a multivariate form of integration by parts in such cases the optimal tariff is cost based

information and incentives the economics of carrots and sticks prize lecture to the memory of alfred nobel december 9 1996 this abstract was borrowed from another version of this item

externalities and fundamental nonconvexities a reconciliation of approaches to general equilibrium externality modeling and implications for decentralization abstract starrett 1972 33 and boyd and conley 1997 7 approaches to externality modeling are unified by distinguishing between producible and nonproducible public commodities nonconvexities are associated with detrimental producible public commodities but not with nonproducible public commodities in boyd and conley 1997 7 disposability properties costly or costless imply that producible public commodities are either by products e g pollution or joint products e g national defense markets fail for both beneficial and detrimental by products nonconvexities imply that price based equilibria e g pigovian tax equilibrium may not be pareto efficient foley s 1967 1970 17 18 public competitive equilibrium combines price and quantity signals with a unanimity criterion and restores the equivalence between equilibrium and efficiency

the determination of the real exchange rate the productivity approach abstract this paper explains deviations of exchange rates from purchasing power parity with the differences between countries of the relative growth rates of labor productivity between traded and nontraded sectors two cases are considered germany and japan versus their respective major trading partners the results show that the time series methodology yields a more favorable confirmation of the productivity differential model than the cross section regressions in the literature

optimal income taxation and job choice in this paper we study optimal income taxation when different job types exist for workers of different skills each job type has some feasible range of incomes from which workers choose by varying labor supply workers are more productive than others in the jobs that suit them best the model combines features of the classic optimal tax literature with labor variability along the intensive margin with the extensive margin approach where workers make discrete job choices and or participation decisions we find that first best maximin utility can be achieved in the second best and marginal tax rates below the top can be negative or zero

partially verifiable information and mechanism design in a principal agent model with adverse selection we study the implementation of social choice functions when the agent s message space is a correspondence which depends on this true characteristic we characterize such correspondence for which the revelation principle is valid returns must not contradict easily observable elements of the taxpayer s lifestyle in this paper we present a model of two person organizations in which these considerations are important we ask whether the restrictions on fallacious statements inherent in the system are sufficient to achieve the goals of the organization we show that the optimal way of eliciting the agent s response may not be to establish incentives for truthtelling in all instances in our model there is one player the agent who observes the state of the economic system another player the principal takes an action based on the information presented to him by the agent this class of models is often referred to as the principal agent problem in the extensive and growing literature on this problem it has always been assumed that the agent could lie to the principal and therefore that he had to be properly motivated to act at least partially in the principal s interest our formal way of modelling the partial verifiability of information is to introduce the restriction that the agent s responses must lie in a set m o that varies with the true state 0 it is assumed that this set always admits the possibility of responding with the true state the way in which the allowable response set varies with the true state is known to the principal in other respects we retain the usual principal agent formalization in particular the principal is the stackelberg leader in this game he can commit himself to choose a collective action as a function of the message transmitted by the agent whether the variation of the message space with the true observation is purely technological or whether it is induced by the severity of potential actions of the principal

employment hours of work and the optimal taxation of low income families the optimal design of low income support is examined using a structural labour supply model the approach incorporates unobserved heterogeneity fixed costs of work childcare costs and the detailed non convexities of the tax and transfer system the analysis considers purely pareto improving reforms and also optimal design under social welfare functions with different degrees of inequality aversion we explore the gains from tagging and also examine the case for the use of hours contingent payments using the tax schedule for lone parents in the uk as our policy environment the results point to a reformed non linear tax schedule with tax credits only optimal for low earners the results also suggest a welfare improving role for tagging according to child age and for hours contingent payments although the case for the latter is mitigated when hours cannot be monitored or recorded accurately by the tax authorities acknowledgements this study is part of the research program of the esrc centre for the microeconomic analysis of public policy at the ifs we thank stuart adam mike brewer roger gordon guy laroque ian preston emmanuel saez florian scheuer seminar participants at harvard mit jerusalem niesr sole and participants in the mirrlees review the editor and the referees for helpful comments we are alone responsible for all errors and interpretations

negative marginal tax rates and heterogeneity the bulk of the theory of optimal taxation recommends that the marginal tax rate be everywhere positive labor supply is distorted downwards compared with laissez faire the conditions under which the result holds continuous labor supply or intensive margin unobserved productivity constant opportunity cost of work utilitarian planner with a redistributive motive towards lower incomes have been thoroughly investigated jesus seade 1977 1982 ivan werning 2000 martin f hellwig 2007 the purpose of the present paper is to describe how negative marginal tax rates can be optimal keeping with the intensive set up largely studied in the literature when there are multiple dimensions of heterogeneity indeed james a mirrlees 1976 in its section iv indicates along a line that will be pursued further here that the sign of the marginal tax rate cannot be predicted when the agents in the economy differ along several dimensions of heterogeneity workers differ in both their productivities and opportunity costs of work under utilitarianism heterogeneity comes into play through its impact on cardinal utilities how social weights or marginal utilities of income vary with income determines the shape of the optimal tax scheme conditionally on income utility and more importantly its derivative with respect to income may either decrease or increase with work opportunity costs this may vary according to circumstances depending on whether the cost is associated with poor living conditions i e a handicap or reflects a taste for leisure or opportunities outside the labor market such as gardening at home or black market activities for a given income the social weight is proportional to the expected marginal utilities where the expectation is taken over the distribution of work opportunity costs at this income level therefore the social weight curve depends on both the specification of the cardinal utility function and on how the distribution of work opportunity costs changes with income the fact that heterogeneity can blur the redistribution motive through the possible correlation between ability and onerousness of work has been discussed in models where agents have a finite number of types a pioneer work is that of joseph e stiglitz 1982 who shows that the high skilled individual should face a negative marginal tax rate if the low skilled individual s upward incentive constraint binds which is the case if social weights are increasing in type the importance of this observation for policy was pointed out in katherine cuff 2000 who is the first to explicitly link social weights to the opportunity cost of work using alternative choices of cardinal utilities in a model with four types combining two values for productivity and two values for the cost of work robin boadway et al 2002 showed how it can be optimal to have binding upward incentive constraints when high opportunity costs are associated with small social weights

the long run relation between black market and official exchange rates evidence from panel cointegration abstract due to the lack of long time series data on black market exchange rates previous research investigated the relation between black market and official exchange rates only for a couple of countries in this paper we employ time series annual data over the 1973 1990 period from 49 countries as well as panel cointegration techniques to show that the black market and official exchange rates do have a long run relationship the implication is that any foreign exchange or direct controls will have only short run effects on the official rate in the long run the official rate will adjust toward the black market rate

nontradable goods prices and per caita income an application to regional korean data pooled time series cross sectional regional data for korea over the period 1985 1991 are used to investigate points which emerged from the united nations international comparison project the results based on a regional analysis are opposite to those of the icp the prices of services do not increase more rapidly in fast growing than in slow growing regions this regional analysis provides constradictory evidence to the widely recognized stylized fact that the prices of nontradables increase with real per capital income by a larger margin than the prices of tradables increase

experimentation and project selection screening and learning firms must strike a delicate balance between the exploitation of well known business models and the exploration of risky untested approaches in this paper we study financial contracting between an investor and a firm with private information about its returns from exploration and exploitation the investor optimal mechanism offers contracts with different tolerance for failures to screen returns from exploitation and with different exposure to the project s revenues to screen returns from exploration we derive necessary and sufficient conditions for private information about returns from exploration to have zero value to the firm when these conditions fail private information about exploration may even decrease the firm s payoff

the design of income maintenance programmes this paper provides a comprehensive treatment of a basic income maintenance problem for a group of individuals who differ in their income generating abilities it stresses the impact that imperfect information about such abilities has on programme design the analysis serves two purposes first we are able to unify the theoretical literature on the income maintenance problem second we examine the impact of allowing the government to impose workfare on recipients of income support in addition to being of policy interest this is a theoretically challenging problem since it requires solving a multi dimensional screening problem the solution that we find is strikingly simple it separates the poor into two categories with the lower income groups subject to workfare while facing a 100 marginal tax rate on earnings the second group does no public work and is offered a benefit schedule which taxes earnings at a lower rate

human capital polarisation and pareto improving activating welfare human capital not only earns income but also is a source of direct felicity the interaction between these two motives for effort can generate multiple stationary solutions for individual household optimisation this multiplicity freezes any sufficiently unequal initial skill distribution and persistently segregates households into two separate groups one rich and educated one poor and uneducated if public goods are to be financed polarisation is typically pareto inefficient while unconditional transfers only reduce the incentive to accumulate skills activating tax transfer systems that pareto dominate any non redistributing system exist transfers are transitory and a negative marginal income tax is imposed on poor households income

optimal dynamic mechanism design with deadlines a seller maximizes revenue from selling an object in a dynamic environment with buyers that differ in their patience each buyer has a privately known deadline for buying and a privately known valuation first we derive the optimal mechanism neglecting the incentive constraint for the deadline the deadline of the winner determines the time of the allocation and therefore also the amount of information available to the seller when he decides whether to allocate to a buyer depending on the shape of the markup that the seller uses this can lead to a violation of the neglected incentive constraint we give sufficient conditions on the type distribution under which the neglected constraint is fulfilled or violated second for the case that the constraint cannot be neglected we consider a model with two periods and two buyers here the optimal mechanism is implemented by a fixed price in period one and an asymmetric auction in period two the asymmetry which is introduced to prevent the patient type of the first buyer from buying in period one leads to pooling of deadlines at the top of the type space

optimal disability insurance with unobservable skill heterogeneity abstract this paper studies the u s income tax and disability insurance systems in a unified framework with relevant private information and a general social welfare function to that end i develop a dynamic model in which agents differ in labor productivity and disability status which are both private information the optimal allocation can exhibit negative marginal labor income tax rates for high skilled individuals but zero for low skilled individuals which is contrary to standard results also i find that a reform to the optimal system in the calibrated model would significantly improve the u s system the welfare gains amount to a 3 48 percent increase in consumption with a utilitarian social welfare function which might be larger with a non utilitarian function better insurance for people in bad states and reduced intratemporal distortions account for almost all the welfare gains however intertemporal distortions do not appear to play a major role

government expenditure and economic growth a cross country study this paper examines the relationship between the share of government consumption expenditure in gdp and the rate of growth of real per capita gdp the work of the u n international comparison project has recently made available new estimates for over 100 countries of both per capita gdp and the share of government consumption these new estimates are based on direct price comparisons rather than exchange rate conversions as a result the statistics for different countries are more comparable and cross country studies will be more reliable