the relation between price and marginal cost in u s industry a contradiction in a recent article in this journal hall 1988 examined productivity shocks at the industry level derived from constant returns to scale production functions in which firms were assumed to be competitive hall had two important conclusions first he showed that productivity shocks i e solow residuals were correlated with aggregate demand variables implying that the former are not exogenous impulses second his results implied that firms persistently charge prices above marginal costs making inappropriate the constant returns to scale competitive production function assumed in many theoretical frameworks because of the importance of hall s findings the article has led to many extensions evans 1992 confirms the empirical finding of significant correlations between productivity shocks and aggregate demand variables burnside eichenbaum and rebelo 1993 show that this correlation can be explained by introducing labor hoarding into a theoretical model with competitive firms and constant returns to scale production functions the markups above marginal cost are explained by eden and griliches 1991 and galeotti and schiantarelli 1991 by modifying the theoretical production function caballero and lyons 1992 using the hall data and methodology examine the possibility of external economies in the aggregate manufacturing production finally waldmann 199 1 argues in this journal that the

too little or too much r d according to the 1rst generation models of endogenous growth based on expanding product variety the market economy unambiguously generates too little r d later by disentangling returns to specialization from the market power parameter it was shown that with su7ciently low returns to specialization too much r d can occur the present paper takes a step further disentangling the market power parameter from the capital share in 1nal output at a theoretical level this helps 1nding too much r d as well on the other hand in view of the empirically realistic order of magnitude between the parameters disentangling market power and capital share tends to diminish the scope for excess r d finally by di erentiating between net and gross returns to specialization we demonstrate what drives the di ering ine7ciency results in this literature c

cointegration tests and spatial price linkages in regional cattle markets this analysis empirically evaluates spatial linkages in regional cattle markets using cointegration tests of regional price series several markets were not cointegrated over the 1980 through 1987 period however significant increases in cointegration of several regional livestock markets are observed through the 1980s the increased cointegration parallels significant structural changes in the livestock industry a formal analysis of market characteristics reveals that distances between markets industry concentration ratios market volumes and market types have significant influences on cointegration relationships between markets

purchasing power parity yet again evidence from spatially separated commodity markets abstract this paper examines the empirical validity of the law of one price by exploiting the non stationarity of prices set in us dollars of varieties of wheat that are traded simultaneously in the usa rotterdam and japan we demonstrate the crucial role of transport costs in achieving cointegration long run ppp although systematic short run deviations from ppp occur we show that this does not imply profitable arbitrage opportunities jel c5 f3 g1

taste for diversity and the optimality of economic growth abstract we disentangle the taste for diversity in consumption present in endogenous growth models with expanding product variety from the elasticity of substitution between consumption goods this seriously affects the welfare analysis of the model if taste for diversity is relatively small the market rate of growth may be suboptimally large

differences in pollution levels among civil law countries a possible interpretation abstract the aim of this paper is to shed light on the way the legal systems of different countries can explain the discrepancies in their pollution levels in particular we underline the factors of capital accumulation and the financial market development that are driven among other things by the various levels of protection accorded by the legal system to both shareholders and creditors the research develops in two directions firstly we supply a theoretical analysis to explain how constraints on the process of capital accruement affect the pollution level in the model a crucial role is assigned to the rate of interest and its relationship with discount rates which constitutes an important variable in decisions to implement anti pollution devices secondly we perform an econometric analysis using the data of eighty five countries belonging to the legal family of civil law for the period from 1992 to 2003 adopting four pollution indicators as dependent variables our main findings are that legal families and financial market development can help to explain the differences in environmental indicators observed among nations

purchasing power parity and unit root tests using panel data abstract this paper reports the results of unit root tests for real exchange rates using a panel framework this panel approach provides greatly improved power compared to conventional univariate time series unit root tests we obtain evidence supporting ppp over the recent flexible exchange rate period for g 6 and oecd countries we show explicitly that failure to find such evidence in previous research was due to the low power of the tests

optimal timing problems in environmental economics abstract because of the uncertainties and irreversibilities that are often inherent in environmental degradation its prevention and its economic consequences environmental policy design can involve important problems of timing i use a simple two period model to illustrate these optimal timing problems and their implications for environmental policy i then lay out and solve a continuous time model of policy adoption in which the policy itself entails sunk costs and environmental damage is irreversible the model generalizes earlier work in that it includes two stochastic state variables one captures uncertainty over environmental change and the other captures uncertainty over the social costs of environmental damage solutions of the model are used to show the implications of these two types of uncertainty for the timing of policy adoption

real exchange rate behavior abstract using random simulations with artificial data with identical sample characteristics to the long sample exchange rate data employed by lothian and taylor lothian j r and taylor m p 1996 the recent float from the perspective of the past two centuries journal of political economy 104 488 509 we show that standard unit root tests have extremely low power over sample sizes corresponding to the recent float the probability of rejecting the null hypothesis when it is false is extremely low with 20 years or even 50 years of data and only reaches an acceptable level over much longer spans

neoclassical growth the j curve for abatement and the inverted u curve for pollution abstract this paper reexamines the neoclassical environmental growth model of forster to gain insights into the dynamic relationships among pollution abatement effort and economic development whereas the model has heretofore been used to examine steady state levels of capital consumption and environmental quality it also provides a theoretical basis for recent empirical research on j curves for abatement effort and inverted u curves for pollution

stoking the fires co2 emissions and economic growth abstract we examine the relationship between economic development and carbon dioxide emissions a greenhouse gas central to global warming predictions estimates derived from global panel data suggest a diminishing marginal propensity to emit mpe carbon dioxide as gdp per capita rises despite this global carbon dioxide emissions growth will continue at 1 8 percent per annum for the foreseeable future a result that is not sensitive to average output growth instead emissions growth continues because output and population will grow most rapidly in lower income nations with high mpes this latter feature emphasizes the distributional consequences of policies to reduce emissions

are real exchange rates nonstationary evidence from a panel data test it is well documented that real exchange rates between the united states and many industrialized countries in the post bretton woods period are integrated this result implies that purchasing power parity ppp does not hold even as a long run relationship this paper demonstrates that the failure to reject the unit root hypothesis may result from the low power of existing univariate test procedures i test for unit roots in real exchange rates by employing a more powerful panel based procedure using both cpi and wpi real dollar exchange rate data i strongly reject the null hypothesis of a unit root my results provide overwhelming support for the long run ppp under the current float copyright 1996 by ohio state university press

an alternative analysis of apparent ekc type transitions abstract the hypothesis of the environmental kuznets curve ekc depends upon the assumption that countries pass through a similar environmental impact trajectory as they experience income growth implying that income levels determine pollution levels the authors present evidence that this is not representative of the way many individual country s pollution emission trajectories evolve and question the emphasis on income determinism by the ekc the study proposes that nonlinear dynamic systems analysis provides a more complete description of individual country pollution trajectories in the case of co 2 emissions the nonlinear time trajectories show abrupt transitions that occur contemporaneously with historical events and over a broad range of incomes

the extent of the market and the supply of regulation we present a model in which setting up and running a regulatory institution takes a fixed cost as a consequence the supply of regulation is limited by the extent of the market we test three implications of this model first jurisdictions with larger populations affected by a given regulation are more likely to have it second jurisdictions with lower incremental fixed costs of introducing and administering new regulations should regulate more this implies that regulation spreads from higher to lower population jurisdictions and that jurisdictions that build up transferable regulatory capabilities should regulate more intensely consistent with the model we find that higher population u s states have more pages of legislation and adopt particular laws earlier in their history than do smaller states we also find that the regulation of entry the regulation of labor and the military draft are more extensive in countries with larger populations as well as in civil law countries where we argue that the incremental fixed costs are lower

optimal growth with decreasing marginal impatience abstract this paper analyses the long run dynamics of a continuous time infinite horizon optimal growth model with identical households where the households rate of time preference is endogenously determined however unlike the existing literature we assume that households have decreasing marginal impatience i e the instantaneous discount rate is negatively related to the current consumption with this assumption we analyse the stability and uniqueness of the long run equilibrium we show that contrary to the general belief a negative relationship between the instantaneous discount rate and the household s current consumption does not necessarily result in instability of the dynamic system however even a stable system may be characterized by multiple equilibria so that the initial condition becomes important in determining the long run behaviour of the economy we derive a set of sufficient conditions for stability and uniqueness in this context

carbon intensity and economic development 1962 1991 a brief exploration of the environmental kuznets curve the relationship between national carbon dioxide emissions intensity co2 emitted per unit of gross domestic product and level of economic development has changed from essentially linear in 1962 to strongly curvilinear in 1991 the inverted u curve reached statistical significance briefly in the early 1970s and increasingly since 1982 this is the result not of groups of countries passing through stages of development but of efficiency improvements in a small number of wealthy countries combined with worse performance in poor and middle income countries the curvilinear relation is deepening and is likely to persist due to constraints on poorer countries in the world economy

a reason for quantity regulation in a variety of situations governments regulate undesirable activities by controlling quantities rather than charging taxes blue laws prohibit all liquor sales on sundays rather than impose higher taxes on that day zoning restrictions limit commercial construction in residential areas rather than charge for nuisance to neighbors anti smoking and anti trust laws restrict rather than tax particular conduct fishing and hunting rules allow hunting during particular time periods rather than tax the catch pollution controls impose limits rather than tax emissions quantity regulations are common in the financial sphere as well in the united states banking regulations for many years prohibited interstate banking as well as ownership of investment banks by commercial banks in many countries commercial banks are limited in the amount of various activities they can pursue such as real estate investments or borrowing in foreign currency in some countries banking laws prohibit all lending to the parties related to the owners of the bank the so called related lending rather than impose liability rules on loans to related parties that are found to be fraudulent or unsafe rafael la porta et al 2000 despite this common practice economists generally prefer taxes and liability rules to quantity controls and property rights rules robert ellickson 1973 louis kaplow and steven shavell 1996 1997 nathaniel keohane et al 1998 as the instrument for reducing undesirable conduct when explaining why quantity regulations are so pervasive they first make the political economy argument that quantity restrictions are favored by incumbent firms that wish to deter entry james buchanan and gordon tullock 1975 but this argument is not general it does not explain such quantity restrictions as blue laws and hunting and fishing regulations which affect all market participants equally some academics also argue that because certain activities such as smoking are seen as morally wrong by the community their level is regulated at zero in other instances however such as pollution and hunting positive but limited levels of activity are allowed inconsistent with the moral argument that the reason for quantity regulation is the special attraction of zero in this paper we present an alternative reason for quantity regulations one from the perspective of a benevolent government we begin with the observation of gary becker and george stigler 1974 that law enforcement is not free but is fundamentally an economic problem throughout human history and throughout the world today there are chronic problems of under enforcement witness the low level of tax compliance in much of the developing world and over enforcement by politically motivated prosecutors or regulators an analysis of pigouvian taxes versus quantity restrictions must recognize that in reality neither policy is free and automatic to enforce in general the choice of policies itself can facilitate or discourage enforcement in two ways first policies can shape the incentives for enforcement second policies can influence the costs of enforcement in our earlier work glaeser and sheifer 2000 glaeser et al 2001 we have focused on incentives and shown that quantity regulations can be used as an optimal instrument to raise the rewards to law enforcers for identifying violations here we focus not on the incentives for the enforcers but on the costs of finding violations these costs are often lower in the case of quantity restrictions we show that even when quantity regulations unlike taxes restrict some socially efficient conduct the reduced costs of identifying violations can enhance enforcement and overall efficiency such reliance of quantity regulation is especially important when private enforcement is crucial as in the case of enforcing department of economics harvard university cambridge ma 02138 we thank the national science foundation for financial support and louis kaplow for extremely helpful comments

investor protection and corporate governance recent research has documented large differences among countries in ownership concentration in publicly traded firms in the breadth and depth of capital markets in dividend policies and in the access of firms to external finance a common element to the explanations of these differences is how well investors both shareholders and creditors are protected by law from expropriation by the managers and controlling shareholders of firms we describe the differences in laws and the effectiveness of their enforcement across countries discuss the possible origins of these differences summarize their consequences and assess potential strategies of corporate governance reform we argue that the legal approach is a more fruitful way to understand corporate governance and its reform than the conventional distinction between bank centered and market centered financial systems

is there always too little research in endogenous growth with expanding product variety abstract it is generally believed that models of endogenous growth with expanding product variety typically yield a too low level of research we show here that this result is due to the implicit choice of a particular value for a crucial parameter once this parameter is set free one finds that too much research can occur as well

purchasing power parity over two centuries strengthening the case for real exchange rate stability a reply to cuddington and liang cuddington and liang 2000 purchasing power parity over two centuries journal of international money and finance 19 751 755 examine the long span of sterling dollar real exchange rate data of lothian and taylor 1996 real exchange rate behavior the recent float from the perspective of the past two centuries journal of political economy 104 488 509 and claim to reject long run purchasing power parity by fitting time trends or by considering very high order autoregresssive representations this reply demonstrates however that the central claims of lothian and taylor are in fact strengthened by the implications of cuddington and liang s analysis in that while the economic importance of introducing trend terms is slight this leads to a faster estimated speed of mean reversion c 2000 elsevier science ltd all rights reserved jel classification f31 f41 c22

a panel project on purchasing power parity mean reversion within and between countries abstract previous time series studies have shown evidence of mean reversion in real exchange rates deviations from purchasing power parity ppp appear to have half lives of approximately four years however the long samples required for statistical significance are unavailable for most currencies and are potentially inappropriate because of regime changes in this study we re examine deviations from ppp using a panel of 150 countries and 45 annual post wwii observations our panel shows strong evidence of mean reversion that is similar to that from long time series ppp deviations are eroded at a rate of approximately 15 annually i e their half life is around four years such findings can be masked in time series data but are relatively easy to find in cross sections

spatial competition and geographic grain transportation demand on the mississippi and illinois rivers using a model of spatial competition between grain elevators i estimate a model of transportation demand for grain elevators located along the mississippi and illinois rivers this analysis uses a unique set of interview data collected by the tennessee valley authority tva both the theory and the data suggest that there are geographic patterns in barge demand elasticity patterns which are empirically uncovered using an endogenous switch point model these results are of central importance to policy makers as they call into question assumptions made by the models currently used for measuring the benefits of inland waterway improvements

income inequality and pollution a reassessment of the environmental kuznets curve abstract improvements in some measures of air and water quality can accompany rising per capita income as illustrated by the so called environmental kuznets curve for pollution variables which show such a relationship we hypothesize that a more equitable distribution of power contributes to these outcomes by enhancing the influence on policy of those who bear the costs of pollution relative to the influence of those who benefit from pollution generating activities an empirical analysis of international variations in seven indicators of air and water quality supports this hypothesis literacy political rights and civil liberties are found to have particularly strong effects on environmental quality in low income countries

the effects of railroad development on price convergence among the states of the usa from 1866 to 1906 this study examines the effects of the reduced transaction costs on the price behaviours in the second half of the nineteenth century where declines in transaction costs were mainly caused by railroad development during this period it employs a panel test introduced by levin and lin 1992 on the convergence of wheat and corn prices using a panel of 48 us states from 1866 to 1906 the results show that by decreasing transportation costs railroads played an important role in price convergence among states of the usa for wheat and corn during the postbellum period

transactions costs and nonlinear adjustment in real exchange rates an empirical investigation eolquilibrium models of real exchange rate determination in the presence of transactions costs imply a nonlinear adjustment process toward purchasing power parity ppp conventional cointegration tests which ignore the effect of transactions costs may be biased against the long run ppp hypothesis our results using both monthly data for the interwar period and annual data spanning two centuries clearly reject the linear framework in favor of an exponential smooth transition autoregressive process the systematic pattern in the estimates of the nonlinear models provides strong evidence of mean reverting behavior for ppp deviations and helps explain the mixed results of previous studies

on impatience economic growth and the environmental kuznets curve a dynamic analysis of resource management the paper presents a dynamic analysis of natural resource management and investigates some key factors that affect optimal management and resource conservation using a recursive specification of time preferences we show how endogenous discounting and impatience can affect the motivation for both capital investments and environmental preservation we examine the relationships between economic growth and environmental quality endogenous discounting provides new insights in the economic dynamics underlying the environmental kuznets curve by treating growth as endogenous we examine how externalities and economic growth interact with each other we investigate how economic development can contribute to an increased demand for environmental preservation as an important new result we also show how poverty can contribute to environmental degradation

finance and the sources of growth the authors evaluate whether the level of development in the banking sector exerts a causal impact on economic growth and its sources total factor productivity growth physical capital accumulation and private saving they use 1 a pure cross country instrumental variable estimator to extract the exogenous component of banking development and 2 a new panel technique that controls for country specific effects and endogeneity they find that banks do exert a large causal impact on total factor productivity growth which feeds through to overall gdp gross domestic product growth the long run links between banking development and both capital growth and private savings are more tenuous

spatial market integration in the presence of threshold effects a large body of research has evaluated price linkages in spatially separate markets much recent research has applied models appropriate for nonstationary data such analyses have been criticized for their ignorance of transactions costs which may inhibit price adjustments and thus affect tests of integration this analysis utilizes threshold autoregression and cointegration models to account for a neutral band representing transactions costs we evaluate daily price linkages among four corn and four soybean markets in north carolina nonlinear impulse response functions are used to investigate dynamic patterns of adjustments to shocks our results confirm the presence of thresholds and indicate strong support for market integration though adjustments following shocks may take many days to be complete in every case the threshold models suggest much faster adjustments in response to deviations from equilibrium than is the case when threshold behavior is ignored a large amount of empirical research has evaluated the extent to which spatially separate markets are integrated though the term is used loosely in the literature tests of market integration usually consider the extent to which shocks are transmitted among spatially separate markets the integration of markets can have important implications for price discovery and the operation of the market since persistent deviations from integration may imply riskless profit opportunities for spatial traders