parity reversion in real exchange rates during the post bretton woods period abstract a common view among recent studies on purchasing power parity is that the post bretton woods period is far too short to reveal any significant parity reversion in individual series of real exchange rates is this really so the answer this study shows depends very much on the statistical test being used two efficient univariate unit root tests are applied to uncover parity reversion these tests require much shorter sample sizes than conventional tests to attain the same statistical power empirical results show that parity reversion can be unveiled over the modern float if an efficient unit root test is applied

nonlinear dynamics in deviations from the law of one price a broad based empirical study abstract in this paper we test empirically the validity of the law of one price using data for five major bilateral us dollar exchange rates and nine goods sectors during the recent floating exchange rate regime since the early 1970s using threshold autoregressive models we find strong evidence of nonlinear mean reversion in deviations from the law of one price with plausible convergence speeds consistent with theoretical arguments on international goods markets arbitrage under transactions costs and with an emerging strand of empirical literature these results contribute towards forming a consensus view in favor of discrete regime switching in deviations from the law of one price and the presence of differing nonzero transactions costs across a broad range of goods and countries

generators bidding behavior in the nyiso day ahead wholesale electricity market this paper proposes a statistical and econometric model to analyze the generators bidding behavior in the nyiso day ahead wholesale electricity market the generator level bidding data show very strong persistence in generators grouping choices over time using dynamic random effect ordered probit model we find that persistence is characterized by positive state dependence and unobserved heterogeneity and state dependence is more important than unobserved heterogeneity the finding of true state dependence suggests a scope for economic policy intervention if nyiso can implement an effective policy to switch generators from higher price groups to lower price groups the effect is likely to be lasting as a result the market price can be lowered in the long run generators offered capacity is estimated by a two stage sample selection model the estimated results show that generators in higher priced groups tend to withhold their capacity strategically to push up market prices it further confirms the importance of an effective policy to turn generators into lower price groups in order to mitigate unexpected price spikes the simulated market prices based on our estimated aggregate supply curve can replicate most volatility of actual da market prices applying our models to different demand assumptions we find that demand conditions can affect market prices significantly it validates the importance of introducing demand side management during the restructure of electricity industry

deviations from purchasing power parity in the long run this paper demonstrates that deviations from purchasing power parity reveal a remarkable and possibly startling consistency with martingale behavior during both fixed and flexible rate periods for a wide variety of countries and in both monthly and annual data since this pattern appears to be much more general than one would expect on the basis of models founded on international commodity arbitrage the paper proposes an alternative explanation which instead relies on financial arbitrage in bonds as the underlying mechanism this paper will demonstrate that deviations from purchasing power parity ppp reveal a remarkable and possibly startling consistency with martingale behavior during both fixed and flexible exchange rate periods for a wide variety of countries and in both monthly and annual data this pattern appears to be much more general than one would expect on the basis of models founded on international commodity arbitrage the paper therefore proposes an alternative explanation which does not presuppose free trade in goods but which instead relies on financial arbitrage in bonds as the underlying mechanism the major implication of the theory and the results is that ppp is as likely to be violated in the long as in the short run as an empirical matter deviations from ppp can be observed for most currencies at any instant see kravis et al 21 stockman 37 and genberg 15 among others these deviations are typically both cumulative and persistent the real exchange rate can remain on either side of parity for lengthy but variable time intervals of a year or more as a consequence the current consensus shared

potential pitfalls for the purchasing power parity puzzle sampling and specification biases in mean reversion tests of the law of one price the ppp puzzle is based on empirical evidence that international price differences for individual goods loop or baskets of goods ppp appear highly persistent or even nonstationary the present consensus is these price differences have a half life that is of the order of five years at best and infinity at worst this seems unreasonable in a world where transportation and transaction costs appear so low as to encourage arbitrage and the convergence of price gaps over much shorter horizons typically days or weeks however current empirics rely on a particular choice of methodology involving i relatively low frequency monthly quarterly or annual data and ii a linear model specification in fact these methodological choices are not innocent and they can be shown to bias analysis towards findings of slow convergence and a random walk intuitively if we suspect that the actual adjustment horizon is of the order of days then monthly and annual data cannot be expected to reveal it if we suspect arbitrage costs are high enough to produce a substantial band of inaction then a linear model will fail to support convergence if the process spends considerable time random walking in that band thus when testing for ppp or loop model specification and data sampling should not proceed without consideration of the actual institutional context and logistical framework of markets

simple solutions to the initial conditions problem in dynamic nonlinear panel data models with unobserved heterogeneity i study a simple widely applicable approach to handling the initial conditions problem in dynamic nonlinear unobserved effects models rather than attempting to obtain the joint distribution of all outcomes of the endogenous variables i propose finding the distribution conditional on the initial value and the observed history of strictly exogenous explanatory variables the approach is flexible and results in simple estimation strategies for at least three leading dynamic nonlinear models probit tobit and poisson regression i treat the general problem of estimating average partial effects and show that simple estimators exist for important special cases copyright 2005 john wiley sons ltd

estimating direct and indirect rebound effects for u s households with input output analysis part 1 theoretical framework abstract this is the first part of a two part paper providing an analytical model of the indirect rebound effect given a direct rebound estimate that integrates consumer demand theory with the embodied energy of household spending from environmentally extended input output analysis the second part applies the model developed in part one to simulate the direct and indirect rebound for the average u s household in terms of primary energy co2e nox and so2 emissions and for energy efficiency investments in electricity natural gas or gasoline services part one provides a critical review of the largely independent economic and industrial ecology literatures on the indirect rebound by studying the two goods case and the n goods case we demonstrate that the indirect rebound is bounded by the consumer budget constraint and inversely related to the direct rebound we also compare the common proportional spending and income elasticity spending assumptions with our model of cross price elasticities including both substitution and income effects for the indirect rebound by assuming zero incremental capital costs and the same embodied energy as conventional technologies for efficient appliances we model an upper bound of the indirect rebound future work should also consider the increase in consumer welfare possible through the rebound effect

ppp strikes back aggregation and the real exchange rate we show the importance of a dynamic aggregation bias in accounting for the ppp puzzle we prove that the aggregate real exchange rate is persistent because its components have heterogeneous dynamics established time series and panel methods fail to control for this using eurostat data we find that when heterogeneity is taken into account the estimated persistence of real exchange rates falls dramatically its half life for instance may fall to as low as eleven months significantly below the consensus view of three to five years

was it real the exchange rate interest differential relation over the modern floating rate period in this paper we explore the relationship between real exchange rates and real interest rate differentials in the united states germany japan and the united kingdom contrary to theories based on the joint hypothesis that domestic prices are sticky and monetary disturbances are predominant we find little evidence of a stable relationship between real interest rates and real exchange rates we consider both in sample and out of sample tests one hypothesis that is consistent with our findings is that real disturbances such as productivity shocks may be a major source of exchange rate volatility this paper investigates the empirical relationship between major currency real exchange rates and real interest rates over the modern post march 1973 flexible rate experience the exchange rates examined here include the dollar mark dollar yen and dollar pound rates our two major findings are as follows first the data do not indicate a strong correspondence between real interest rate differentials short term or long term and real exchange rates this finding appears to conflict with the predictions of most monetary and portfolio balance models of exchange rate determination though the conflict can be substantially reconciled if aggregate disturbances are primarily real in nature i e changes in productivity tastes etc it is true that in many cases the sign of the estimated exchange rate interest rate differential relationship is consistent with the possible predominance of financial market disturbances but the relationship is not stable enough to be statistically significant second although one does find some evidence of a unit root in both real exchange rates and long term but not shortterm real interest differentials these two series do not appear to be linearly cointegrated hence the nonstationarity or near nonstationarity in the two series cannot be attributed to the same factor in section i we briefly describe a class of small scale monetary models of exchange rate determination the importance of this class of models for empirical work derives from its strong predictions about how the exchange rate will move

on the failure of purchasing power parity for bilateral exchange rates after 1973 point estimates suggest mean reversion in real exchange rates however it still remains uncomfortable that models without any mean reversion are often compatible with data from the floating period studies with data over longer periods find mean reversion but at the cost of mixing in data from earlier exchange rate arrangements pooling the floating period data potentially mixes country pairs with and without mean reversion we examine tests for mean reversion for individual country pairs where greater power against close alternatives is gained through modeling other economic variables with the real exchange rate by increasing the power of the tests we find strong evidence of mean reversion

empirical estimates of the direct rebound effect a review beginning with william stanley jevons in 1865 a number of authors have claimed that economically justified energy efficiency improvements will increase rather than reduce energy consumption jevons paradox is extremely difficult to test empirically but could have profound implications for energy and climate policy this paper summarises and critiques the arguments and evidence that have been cited in support of jevons paradox focusing in particular on the work of len brookes and harry saunders it identifies some empirical and theoretical weaknesses in these arguments highlights the questions they raise for economic orthodoxy and points to some interesting parallels between these arguments and those used by the biophysical school of ecological economics while the evidence in favour of jevons paradox is far from conclusive it does suggest that economy wide rebound effects are larger than is conventionally assumed and that energy plays a more important role in driving productivity improvements and economic growth than is conventionally assumed 2008 elsevier ltd all rights reserved

real exchange rate behavior the recent float from the perspective of the past two centuries using annual data spanning two centuries for dollar sterling and franc sterling real exchange rates we find strong evidence of mean reverting real exchange rate behavior using simple stationary autoregressive models estimated on prefloat data we easily outperform nonstationary real exchange rate models in dynamic forecasting exercises over the recent float such stationary univariate equations explain 60 80 percent of the in sample variation in real exchange rates although the degree of short run persistence may be high the econometric estimates imply a half life of shocks to the real exchange rate of about 6 years for dollar sterling and a little under 3 years for franc sterling

state of the art unit root tests and purchasing power parity although the question of whether purchasing power parity ppp holds in the long run has been extensively studied the answer is still controversial some of the strongest evidence is provided by taylor the review of economics and statistics 84 2002 139 150 who concludes that long run ppp held over the 20th century we argue that this conclusion is quite sensitive to the use of sub optimal lag selection in unit root tests using superior lag selection methods we find that long run ppp held for the real exchange rates of only 9 out of the 16 industrialized countries in taylor s sample with the u s dollar as the base currency

on cross country differences in the persistence of real exchange rates abstract previous findings of long run purchasing power parity come mainly from data for industrial countries raising the issue of whether the results suffer sample selection bias and exaggerate the general relevance of parity reversion this study uncovers substantial cross country heterogeneity in the persistence of deviations from parity the results show that it is more likely rather than less likely to find parity reversion for developing countries than industrial countries although some persistence variations may partly reflect country differences in structural characteristics such as inflation experience and government spending a considerable portion of those variations seems unaccounted for

economic energy and greenhouse emissions impacts of some consumer choice technology and government outlay options abstract the impacts of selected spending options in the australian economy are determined in terms of energy consumption greenhouse gas emissions and a range of economic parameters six case studies of one current practice and one alternative environmentally motivated spending option are carried out describing consumer choices technologies and government outlays the assessment method is based on input output theory and as such enables both the direct and indirect effects of spending to be quantified in general the results indicate that pro environmental objectives such as reductions in energy consumption and greenhouse gas emissions are compatible with broad socio economic benefits such as increases in employment and income and reductions in imports

on the empirical failure of purchasing power parity tests summary empirical research on the validity of the purchasing power parity ppp condition is generally based on real exchange rates built using the consumer price index cpi but fails to provide clear support to ppp in this paper we show theoretically that even if the law of one price lop holds for traded goods cpi based real exchange rates are not mean reverting and are neither stationary nor integrated therefore both unit root and stationarity tests should reject their null our theoretical results are validated both by simulations and an empirical application copyright 2014 john wiley sons ltd

size distortions of tests of the null hypothesis of stationarity evidence and implications for the ppp debate abstract tests of the null hypothesis of stationarity against the unit root alternative play an increasingly important role in empirical work in macroeconomics and in international finance we show that the use of conventional asymptotic critical values for stationarity tests may cause extreme size distortions if the model under the null hypothesis is highly persistent this fact calls into question the use of these tests in empirical work we illustrate the practical importance of this point for tests of long run purchasing power parity ppp under the recent float we show that the common practice of viewing tests of stationarity as complementary to tests of the unit root null will tend to result in contradictions and in spurious rejections of long run ppp while the size distortions may be overcome by the use of finite sample critical values the resulting tests tend to have low power under economically plausible assumptions about the half life of deviations from ppp thus the fact that stationarity is not rejected cannot be interpreted as convincing evidence in favor of mean reversion only in the rare case that stationarity is rejected do size corrected tests shed light on the question of long run ppp

do panels help solve the purchasing power parity puzzle although rogoff described the remarkable consensus of 3 to 5 year half lives of purchasing power parity ppp deviations among studies using long horizon data recent works using panel methods with post 1973 data report shorter half lives of 2 to 2 5 years but these studies do not use appropriate techniques to measure persistence we extend median unbiased estimation methods to the panel context calculate both point estimates and confidence intervals and provide strong evidence confirming rogoff s original claim although panel regressions provide more information on the persistence of real exchange rate shocks than univariate regressions they do not help solve the ppp puzzle

panel stationarity tests for purchasing power parity with cross sectional dependence we investigate the purchasing power parity ppp hypothesis for a group of 17 countries using a new panel based test of stationarity that allows for arbitrary cross sectional dependence we treat the short run time series dynamics nonparametrically and thus avoid the need to fit separate and potentially misspecified models for the individual series the statistic is simple to compute and uses standard normal critical values even in the presence of a wide range of different deterministic components we also evaluate the behavior of the test using a factor model to approximate cross sectional dependence and find that it generally improves finite sample performance taken together these features provide a widely applicable solution to the problem of testing for stationarity versus unit roots in macro panel data the test finds significant evidence against the ppp null hypothesis being true even when allowance is made for structural breaks

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

the added value from a general equilibrium analysis of increased efficiency in household energy use this paper investigates the economic impact of a 5 improvement in the uk household energy efficiency focussing specifically on total energy rebound effects the impact is measured through simulations using models that have increasing degrees of endogeneity but are calibrated on a common data set moving from a basic partial equilibrium approach to a fully specified general equilibrium treatment the size of the rebound effect is shown to depend on changes in household income aggregate economic activity and relative prices that can only be captured through a general equilibrium model

strategic bidding and rebidding in electricity markets abstract successful deregulation in electricity markets depends crucially on the ability of market regulation to promote and maintain free competition there are however important physical characteristics in electricity markets such as the constraints imposed by the physical transmission infrastructure that have the potential to undermine competition and provide opportunities for market participants to exploit temporary positions of market power in this paper the regional market of queensland australia is analysed it is found that strategic behaviour by generators exists and is closely related to the occurrence of the kind of extreme price events that characterise many deregulated electricity markets in addition rebidding behaviour by base load generators immediately after extreme price events is shown to have negative impacts on the operation of the market the key message is that promotion of competition in electricity markets can have undesirable consequences unless the regulatory policy is carefully designed to counter strategic behaviour by market participants

aggregation is not the solution the ppp puzzle strikes back we acknowledge financial support from the spanish ministry of education through grants sej2006 00369 and sej2005 05215 the fundacion ramon areces the barcelona economics program of crea and from the aragon s research unit seim

aggregate real exchange rate persistence through the lens of sectoral data a novel approach to analyzing real exchange rate rer persistence and its sources is presented using highly disaggregated data for a group of eu 15 countries it is shown that the distribution of sectoral persistence is highly heterogeneous and skewed to the right so that a limited number of sectors are responsible for the high levels of persistence observed at the aggregate level quantile regression has been employed to investigate whether traditional theories such as the lack of arbitrage due to nontradability or imperfect competition combined with price stickiness are able to account for the slow reversion to parity of rers