revisited are shocks to energy consumption permanent or temporary new evidence from a panel suradf approach abstract this paper explores whether the hypothesis of energy consumption stationarity is supported in different regions the stationarity properties indicate that the impact of a reduction in energy consumption or a realignment policy is only temporary and over time the series will revert back to the trend path this paper first applies the panel seemingly unrelated regressions augmented dickey fuller panel suradf test developed by breuer et al breuer j b mcnown r wallace m s 2001 misleading inferences from panel unit root tests with an illustration from purchasing power parity review of international economics 9 3 482 493 which allows us to account for possible cross sectional effects and to identify how many and which members of the panel contain a unit root the main conclusion is that the stationarity of energy consumption will be affected by the differences among the five regions made up of 84 countries during the period 1971 2003 similar conclusions are reached when we analyze country groups based on levels of development moreover the results reveal that conventional panel unit root tests can lead to misleading inferences which are biased towards stationarity even if only one series in the panel is strongly stationary lastly some policy implications emerge from our results

testing for common features in north american energy markets abstract using recent advances in the field of applied econometrics we explore the strength of shared trends and shared cycles between north american natural gas and crude oil markets in doing so we use daily data from january 1991 to april 2001 on spot u s henry hub natural gas and wti crude oil prices the results show that there has been decoupling of the prices of these two sources of energy as a result of oil and gas deregulation in the united states we also investigate the interconnectedness of north american natural gas markets and find that north american natural gas prices are largely defined by the u s henry hub price trends

the role of energy in real business cycle models abstract this paper modifies hansen s 1985 analysis of a real business cycle mode with indivisible labor by explicitly including energy as a productive input and modelling the relative price of energy as an exogenous random process one goal is to determine the extent to which the introduction of energy price shocks reduces the reliance of the real business cycle model on unobserved technology shocks the other goal following christiano and eichenbaum 1991 is to compare the correlation between real wages and hours predicted by the energy inclusive model to that predicted by hansen s model

geometric brownian motion and structural breaks in oil prices a quantitative analysis the purpose of this paper is to present a quantitative analyses of oil price s path we try to argue that despite its parsimony and simplicity geometric brownian motion can perform well as a proxy for the movement of oil prices and for a state variable to evaluate oil deposits we base our argument on evidences of very low speed of mean reverting or long half life since unit root tests only can reject its null hypothesis in a sample longer than 100 years on the other hand we reject the null hypothesis of unit root with two endogenous breaks showing that the usual rejection can be attributed to omitted structural breaks we conclude that the average half life of oil price between 4 and 8 years depending on the model chosen is long enough to allow a good approximation as a geometric brownian motion

are oil shocks permanent or temporary panel data evidence from crude oil and ngl production in 60 countries this paper examines the unit root properties of crude oil production for 60 countries employing a range of panel data unit root tests for the period 1971 to 2003 the study first employs a number of panel data tests that do not accommodate structural breaks and then proceeds to apply the lagrange multiplier lm panel unit root test with one structural break the results of the panel data tests without a structural break are inconclusive with at best mixed support for joint stationarity the findings from the lm panel unit root test with a structural break however are conclusive suggesting that for a world panel and smaller regional based panels crude oil and ngl production are jointly stationary

the impact of surplus schooling on productivity and earnings this article examines the impact of surplus schooling on individual productivity and earnings it proposes a model that divides workers education into two components education that is required and thus fully utilized in the job and education that exceeds the amount required and thus may be underutilized in the job the model is tested with data from the 1969 1973 and 1977 quality of working life surveys quinn and staines 1979 required schooling for each occupation is derived from estimates by job incumbents and by the dictionary of occupational titles the results show thqt surplus or underutilized education is rewarded at a lower rate than required education with the actual return dependent on the type of job

further evidence for sraffa s interpretation of ricardo samuel hollander 1973 1975 1979 has attracted much attention by disputing piero sraffa s famous corn model interpretation of ricardo s 1815 essay on profits john eatwell 1975 and more recently pierangelo garegnani 1982 in this journal have come to sraffa s defence at issue is sraffa s suggestion contained in the introduction to the first volume of his edition of ricardo s works that the rational foundation of ricardo s dictum that the profits of the farmer regulate the profits of all other trades is the assumption that the inputs and outputs of agricultural production are roughly homogenous and that the rate of profit in agriculture may therefore be conceived as a ratio of physical quantities independent of valuation sraffa 1951 p xxxi eatwell and garegnani base their defences of this proposition upon exegeses of the relevant text and correspondence in this short paper i will show that further evidence in support of sraffa s view may be found in a now little known article written by robert torrens which appeared in the edinburgh review of october 1819 1 that article which was ostensibly a review of four pamphlets of robert owen and which bore the running title mr owen s plans for relieving the national distress details a corn model theory of profits in much more explicit terms than does ricardo s essay on profits ricardo moreover was not only familiar with the article but wrote approvingly of it in several letters to j r mcculloch on 28 february 1820 he wrote

do oil price shocks matter evidence for some european countries this paper analyzes the oil price macroeconomy relationship by means of analyzing the impact of oil prices on inflation and industrial production indexes for many european countries using quarterly data for the period 1960 1999 first we test for cointegration allowing for structural breaks among the variables second and in order to account for the possible non linear relationships we use different transformation of oil price data the main results suggest that oil prices have permanent effects on inflation and short run but asymmetric effects on production growth rates furthermore significant differences are found among the responses of the countries to these shocks

the corn model gluts and surplus value the controversy over ricardo s corn model has focused on the interpretation of his early writings here ricardo s later use of a corn model example in his dispute with malthus over gluts is discussed malthus s own use of a corn model table in attempting to justify his use of a labour commanded measure of value is analysed it is shown that he calculates what marx was to describe as surplus value from the physical conditions of production and the real wage copyright 2006 oxford university press

is energy consumption per capita broken stationary new evidence from regional based panels abstract for the first time a new panel unit root testing procedure developed by 51 carrion i silvestre et al 2005 breaking the panels an application to gdp per capita econometrics journal 8 159 175 is applied to re investigate the stationarity of energy consumption per capita for 7 regional panel sets covering the 1971 2002 period with structural breaks and cross sectional correlations introduced into the model it becomes clear that all regional based panels of energy consumption per capita are stationary the structural breakpoints identify the likely causes of major changes in energy consumption in the past the findings underscore the importance of accounting for exogenous shocks to a series and offer several important implications for policy makers and energy economists

political regime change and the real interest rate the effect of changes in policy regimes on real interest rates has important implications for financial and economic theory there is little current evidence that policy regime changes have any impact on the level of real interest rates we use large political changes as our measure of policy regime changes changes in presidential administration are more significantly correlated with real rate changes than are changes in the federal reserve chair or the mean shift points identified by garcia and perron 1996 using time series methods we also show that change of party control of congress is a significant factor explaining real rates we argue that theoretical models built on the assumptions of constant or policy invariant real interest rates are at variance with the empirical evidence

this is what happened to the oil price macroeconomy relationship abstract many of the quarterly oil price increases observed since 1985 are corrections to even bigger oil price decreases the previous quarter when one looks at the net increase in oil prices over the year recent data are consistent with the historical correlation between oil shocks and recessions

overeducation undereducation and asymmetric information in occupational mobility due to short term asymmetric information overeducated and undereducated workers are shown to have different optimal strategies in seeking upward occupational mobility into their next positions undereducated workers typically have other human capital strengths but these strengths are not marketable to outsiders overeducated workers typically have other human capital weaknesses that are not apparent to outsiders while their excess schooling is marketable in labour markets with dynamic asymmetric information this article presents empirical evidence showing that job tenure increases the probability of upward occupational mobility more if individuals are undereducated moreover the probability of finding upward occupational mobility is increased by overeducated workers engaging in firm switching this article also validates prior empirical studies finding overeducated workers more likely to self report engaging in firm switching activities and more likely to experience upward occupational mobility than o

interpreting ricardo a rejoinder to peach this note answers terry peach s 1998 response to our criticisms of his interpretation of ricardo we show that the available evidence supports sraffa s interpretation the arguments put forward by peach far from undermining that interpretation or furthering an understanding of ricardo s project do little more than catalogue the already well known difficulties that ricardo encountered as he grappled toward a clearer account of the laws that regulate distribution and prices copyright 2002 oxford university press

are shocks to energy consumption permanent or temporary evidence from 182 countries this article applies univariate and panel data unit root tests to annual panel data for 182 countries over the period 1979 2000 to examine the stationarity properties of per capita energy consumption the univariate unit root test can only reject the unit root null for 56 countries or 31 of the sample at the 10 level or better however univariate unit root tests have low power with short spans of data and therefore failure to reject the unit root null should be treated with caution when we apply the panel data unit root test we find overwhelming evidence that energy consumption is stationary we discuss the policy implications of these findings and offer suggestions for future research

oil price shocks stock market economic activity and employment in greece abstract using a multivariate vector autoregression var approach this paper attempts to shed light into the dynamic relationship among oil prices real stock prices interest rates real economic activity and employment for greece the empirical evidence suggests that oil price changes affect real economic activity and employment oil prices are important in explaining stock price movements stock returns do not lead to changes in real activity and employment

overeducation in the labor market this article examines the reasons for the observed discrepancy between workers actual and required levels of schooling and the resulting differences in returns to schooling overeducated workers are found to be younger and to have lower amounts of on the job training than workers with the required level of schooling they also have higher rates of firm and occupational mobility characterized by movement of higher level occupations the findings suggest that overeducation can be explained by the trade off between schooling and other components of human capital and by the mobility patterns of overeducated workers

on interpreting ricardo a reply to sraffians this paper seeks to clarify and defend aspects of the interpretation advanced in interpreting ricardo terry peach 1993 in the light of published criticisms by writers of a sraffian persuasion the principal areas of discussion include the corn model interpretation the labor theory of value and the invariable measure of value and the ricardo sraffa relationship copyright 1998 by oxford university press

education and skills mismatch in the italian graduate labour market this paper focuses on education and skills mismatch among italian graduates indicators for over and under utilization of education and under utilization of skills are included as explanatory factors in a wage equation testing theories that could explain the effect of over schooling on wages we find little evidence to support assignment theory and also identify a relatively weak wage effect arising from educational mismatch associated with employers as opposed to employees perceptions of the job requirements our interpretation is that some employers have re categorized jobs as requiring a degree when they were previously filled by non graduates and many have not altered pay scales accordingly

unit root properties of crude oil spot and futures prices in this article we examine whether wti and brent crude oil spot and futures prices at 1 3 and 6 months to maturity contain a unit root with one and two structural breaks employing weekly data over the period 1991 2004 to realise this objective we employ lagrange multiplier lm unit root tests with one and two endogenous structural breaks proposed by lee and strazicich 2003 minimum lagrange multiplier unit root test with two structural breaks review of economics and statistics 85 1082 1089 2004 minimum lm unit root test with one structural break working paper no 04 17 department of economics appalachian state university we find that each of the oil price series can be characterised as a random walk process and that the endogenous structural breaks are significant and meaningful in terms of events that have impacted on world oil markets

world crude oil and natural gas a demand and supply model abstract this paper examines world markets for crude oil and natural gas over the period 1918 1999 it analyzes the time series properties of output and prices and estimates demand and supply elasticities during 1918 1973 and 1973 1999 oil and gas prices were stable during the first period they became volatile afterwards reflecting deep changes in the market structure following the oil shock in 1973 demand price elasticities were too low however demand income elasticities were high supply price elasticities were also too low the elasticity estimates help to explain the market power of the oil producers and price volatility in response to shocks and corroborate elasticity estimates in energy studies

non renewable resource prices deterministic or stochastic trends in this paper we examine temporal properties of 11 natural resource real price series from 1870 to 1990 recent studies by ahrens and sharma trends in natural resource commodity prices deterministic or stochastic j environ econom manage 33 1997 59 74 berck and roberts natural resource prices will they ever turn up j environ econom manage 31 1996 65 78 and slade grade selection under uncertainty least cost last and other anomalies j environ econom manage 15 1988 189 205 among others find that many non renewable resource prices have a stochastic trend we revisit this issue by employing a lagrangian multiplier unit root test that allows for two endogenously determined structural breaks with and without a quadratic trend contrary to previous research we find evidence against the unit root hypothesis for all price series our findings support characterizing natural resource prices as stationary around deterministic trends with structural breaks we additionally show that both pre testing for unit roots with breaks and allowing for breaks in the forecast model can improve forecast accuracy overall the results in this paper are important in both a positive and normative sense without an appropriate understanding of the dynamics of a time series empirical verification of theories forecasting and proper inference are potentially fruitless

returns to investment in education a global update the author updates compilations of rate of return estimates to investment in education published since 1985 and discusses methodological issues surrounding those estimates some key patterns among the three main levels of education primary education continues to exhibit the highest social profitability in all world regions private returns are considerably higher than social returns because of the public subsidization of education the degree of public subsidy increases with the level of education which is regressive social and private returns at all levels generally decline by the level of a country s per capita income overall the returns to female education are higher than those to male education but at individual levels of education the pattern is more mixed the returns to the academic secondary school track are higher than the vocational track since unit cost of vocational education is much higher and the returns for those who work in the private competitive sector of the economy are higher than in the public noncompetitive sector and the returns in the self employment unregulated sector of the economy are higher than in the dependent employment sector controversies in the literature are discussed in the light of the new evidence the undisputable and universal positive correlation between education and earnings can be interpreted in many ways the causation issue on whether education really affects earnings can be answered only with experimental data generated by randomly exposing different people to various amounts of education given the fact that moral and pragmatic considerations prevent the generation of such pure data researchers have to make do with indirect inferences or natural experiments some have been attempted the author looks at the research on overeducation or surplus schooling the conclusions reinforce earlier patterns they confirm that primary education continues to be the number one investment priority in developing countries they also show that educating females is marginally more profitable than educating males that the academic secondary school curriculum is a better investment than the technical vocational tract and that the returns to education obey the same rules as investment in conventional capital that is they decline as investment is expanded