is there private information in the fx market the tokyo experiment it is a common view that private information in the foreign exchange market does not exist we provide evidence against this view the evidence comes from the introduction of trading in tokyo over the lunch hour lunch re turn variance doubles with the introduction of trading which cannot be due to public information since the flow of public information did not change with the trading rules having eliminated public information as the cause we exploit the volatility pattern over the whole day to discriminate between the two alternatives private information and pricing errors three key re sults support the predictions of private information models first the vola tility u shape flattens greater revelation over lunch leaves a smaller share for the morning and afternoon second the u shape tilts upward an impli cation of information whose private value is transitory finally the morning exhibits a clear u shape when tokyo closes over lunch and it disappears when trading is introduced

testing for nonlinear dependence in daily foreign exchange rates the purpose of this article is to investigate whether daily changes in five major foreign exchange rates contain any nonlinearities although the data contain no linear correlation evidence indicates the presence of substantial nonlinearity in a multiplicative rather than additive form further examination reveals that a generalized autoregressive conditional heteroskedasticity model can explain a large part of the nonlinearities for all five exchange rates copyright 1989 by the university of chicago

the behavior of foreign exchange rates the analysis of the distribution of foreign exchange rate changes provides a description of the behavior of foreign exchange rates and its determining underlying process the application of empirical methodologies or further theoretical developments is limited by the nature of this distribution in this paper the empirical analysis of major currencies during the flexible exchange rate period suggests that there is no unique distribution representing the behavior of the foreign exchange rate this however is determined both by foreign exchange management policies and the fundamental economic forces

the distribution of foreign exchange price changes trading day effects and risk measurement a comment in their 1982 study mcfarland pettit and sung 16 mps found that consecutive daily foreign exchange rates conform to neither a normal nor a nonnormal stable process and that day of the week data could be adequately described by a series of different stable distributions the authors have also documented a weekday effect in the foreign exchange market mondays and wednesdays offered higher average price changes than did thursdays and fridays in a more recent study jaffe and westerfield 9 documented negative monday returns for the currencies of the u k canada and australia in estimating the parameters of the distribution mps have utilized the fama and roll 5 6 method which assumes a symmetric distribution jaffe and westerfield 9 report only estimates of the sample moments the sample moments reported in mps s table ii part of which is reproduced in table i here reveal that most currencies especially the minor currencies the australian dollar the spanish peseta and the swedish krona have significant skewness the results indicate that the asymmetric stable paretian distribution may be more appropriate for the overall daily returns this hypothesis is consistent with

a new look at residential electricity demand using household expenditure data the recent push for a federal energy policy that could substantially change electricity prices in the u s highlights the need to obtain accurate residential electricity demand estimates many electricity demand estimates have been obtained based on the assumption that consumers optimize with respect to known marginal prices but increasing empirical evidence suggests that consumers are more likely to respond to average prices under this assumption this paper develops a new strategy based on gmm to estimate household electricity demand our approach allows a national level demand estimation from publicly available expenditure data and utility level consumption data complementing studies that use individual billing data which are richer yet often proprietary we estimate the price elasticity near 1 which is at the upper end in magnitude among the estimates from previous studies we apply our elasticity estimates in a u s climate policy simulation to determine how these elasticity estimates alter consumption and price outcomes compared to the more conservative elasticity estimates commonly used in policy analysis

interest rates and currency prices in a two country world abstract this paper is a theoretical study of the determination of prices interest rates and currency exchange rates set in an infinitely lived two country world which is subject both to stochastic endowment shocks and to monetary instability formulas are obtained for pricing all equity claims nominally denominated bonds and currencies and these formulas are related to earlier closely related results in the theories of money finance international trade

california energy efficiency lessons for the rest of the world or not abstract since the 1970s california s residential electricity consumption per capita has stopped increasing while other states electricity use continued to grow steadily what accounts for california s apparent savings some credit the strict energy efficiency standards for buildings and appliances enacted by california in the mid 1970s they argue that the growing gap between california and other states demonstrates that other states and countries could replicate california s gains by adopting california style regulations and that california should build on its own success by tightening its standards further skeptics might point to three long run trends that differentiate california s electricity demand from other states 1 shifting of the u s population toward warmer climates of the south and west 2 relatively small income elasticity of energy demand in california s temperate climate and 3 evolving differences between the demographics of households in california and other states today differences in climate and demographics account for almost 90 percent of the difference between california s and other states residential electricity use that difference thus provides no lessons for other states or countries considering adopting or tightening their own energy efficiency standards

the statistical properties of daily foreign exchange rates 1974 1983 abstract this paper examines the statistical properties of daily rates of change of five foreign currencies from 1974 to 1983 the main purpose is to discriminate between two competing explanations for the observed heavy tails of the distribution that the data are independently drawn from a heavy tail distribution which remains fixed over time and that the data come from distributions which vary over time evidence point to the rejection of the first hypothesis further investigations show that the rejection can be attributed to changing means and variances in the data which can be described by a simple statistical model

household electricity end use consumption results from econometric and engineering models information about total electricity consumption is available for most households however the electricity consumption related to different end uses e g space heating lighting and services from household appliances are usually not metered metering data are costly to achieve and in this paper we study two methods for end use estimation which can be applied on household data for appliance holdings demographic and economic variables the first method is the engineering model which has been used to calculate the so far only documented norwegian end use results applied on data from a norwegian energy survey the second method is an econometric conditional demand model applied on data from the same survey we compare the numerical results from the two models and give some recommendations regarding choice of end use approach and what questions to implement in household surveys designed to disaggregate electricity consumption

residential energy use and conservation economics and demographics energy consumption in the residential sector offers an important opportunity for conserving resources however much of the current debate regarding energy efficiency in the housing market focuses on the physical and technical determinants of energy consumption neglecting the role of the economic behavior of resident households in this paper we analyze the extent to which the use of gas and electricity is determined by the technical specifications of the dwelling as compared to the demographic characteristics of the residents our analysis is based on a sample of more than 300 000 dutch homes and their occupants the results indicate that residential gas consumption is determined principally by structural dwelling characteristics such as the vintage building type and characteristics of the dwelling while electricity consumption varies more directly with household composition in particular income and family composition combining these results with projections on future economic and demographic trends we find that even absent price increases for residential energy the aging of the population and their increasing wealth will roughly offset improvements in the energy efficiency of the building stock resulting from policy interventions and natural revitalization

commercially available order flow data and exchange rate movements caveat emptor research suggests that customer order flow should help predict exchange rates we make two contributions first we provide a review of the recent literature on order flow and exchange rate movements second we critically evaluate the practical value of customer order flow data that are commercially available to the wider market as well as the forecasting properties of inter dealer order flow in line with microstructure theory we find little evidence that the latter can forecast exchange rates but our results also cast considerable doubt on the practical value to market practitioners of commercially available customer order flow data

long memory in foreign exchange rates using the geweke porter hudak test we find evidence of long memory in exchange rate data this implies that the empirical evidence of unit roots in exchange rates may not be robust to long memory alternatives fractionally integrated autoregressive moving average arfima models are estimated by both the time domain exact maximum likelihood ml method and the frequency domain approximate ml method impulse response functions and forecasts based on these estimated arfima models are evaluated to gain insight into the long memory characteristics of exchange rates some tentative explanations of the long memory found in the exchange rates are discussed

building vintage and electricity use old homes use less electricity in hot weather abstract this paper studies whether electricity use in newer or older residential buildings rises more in response to high temperature in a region of southern california peak electricity demand occurs at the highest temperatures which are predicted to increase due to climate change understanding how newer buildings differ from older buildings improves forecasts of how peak electricity use will grow over time newer buildings are subject to stricter building energy codes but are larger and more likely to have air conditioning hence the cumulative effect is ambiguous this paper combines four large datasets of building and household characteristics weather data and utility data to estimate the electricity temperature response of different building vintages estimation results show that new buildings 1970 2000 have a statistically significantly higher temperature response i e use more electricity than old buildings pre1970 auxiliary regressions with controls for tiered electricity prices number of bedrooms income square footage central air conditioning ownership and type of residential structure partially decompose the effect though california has had extensive energy efficiency building standards that by themselves would lower temperature response for new buildings the cumulative effect of new buildings is an increase in temperature response as new buildings are added aggregate temperature response is predicted to increase

currency fluctuations in the post bretton woods era the international monetary landscape that has emerged since the felling of bretton woods is characterized by a hybrid exchange rate system that lies somewhere between the textbook polar cases of a gold standard and a pure float this system has relatively flexible exchange rates between major countries active central bank intervention in the market for the major currencies and predominantly fixed exchange rates relative to the dollar or to some basket of currencies for less developed countries and newly industrializing nations the majority of research on currency markets since the early 1970s has focused on the characteristics of flexible exchange rates under this hybrid regime my thesis is that this research has been unsuccessful the proportion of monthly or quarterly exchange rate changes that current models can explain is essentially zero even after the fact forecasts that use actual values instead of forecasted values of the explanatory variables cannot explain major currency movements over the post bretton woods era this result is quite surprising since exchange rate changes would be entirely unpredictable only in very special cases of the theoretical models discussed as the discussion below will argue it is not a general implication of market efficiency that exchange rates follow a random walk process 1

deutsche mark dollar volatility intraday activity patterns macroeconomic announcements and longer run dependencies this paper provides a detailed characterization of the volatility in the deutsche mark dollar foreign exchange market using an annual sample of five minute returns the approach captures the intraday activity patterns the macroeconomic announcements and the volatility persistence arch known from daily returns the different features are separately quantified and shown to account for a substantial fraction of return variability both at the intraday and daily level the implications of the results for the interpretation of the fundamental driving forces behind the volatility process is also discussed the efficient market hypothesis contends that financial asset prices provide rational assessments of fundamental values and future payoffs by implication price changes should reflect the arrival and processing of all relevant new information however the proportion of return variability that can be ascribed to public news announcements is low for example cutler poterba and summers 1989 find that even the largest daily price changes in the stock market generally cannot be associated with any significant economic news 1 moreover proxies for the flow of public information e g the number of news items released by reuter s news service berry and hiowe 1994 or dow jones company mitchell and mulherin 1994 explain little of the overall variation thus if private information is ruled out proponents of rational price formation have to assert the existence of important news items

the sub gaussian distribution of currency futures stable paretian or nonstationary this study conducts an empirical test to examine wh ether the observed non normal distribution of currency futures price changes isgenerated by the relationship between maturity and variability in general the author finds that the relationship between maturity and vari ability is not suff icient to explain the observed non normality although some amount of non statio narity is present in the scale and in the characteristic exponent the non norma l stable paretian distribution adequately describes futures price changes for mo st currencies and most contracts during the period covered in thisstudy copyright 1987 by mit press

identifying the interaction between stock market returns and trading flows of investor types looking into the day using daily data abstract this paper introduces a new method for identifying the simultaneity between returns and trading flows the proposed method enables us to identify the intraday interaction using daily data and provides measures of the information content of trading flows and their instantaneous response to public information and information revealed by market prices applying this method to daily data on investor types from the korea stock exchange we find significant intraday bi directional interaction between flows and returns and their latent common drivers altering some of the results of the previous literature based on cholesky assumptions thus we obtain a number of new insights concerning the behavior of investor types

time varying parameters and the out of sample forecasting performance of structural exchange rate models varying parameter estimation techniques based on recursive application of the kalman filter are used to improve the predictive performance of a class of monetary exchange rate models i find that allowing estimated parameters to vary over time enhances the models forecasting performance for the dollar pound dollar mark and dollar yen exchange rates contrary to earlier results in the literature ex post forecasts for the dollar mark rate compare favorably with those obtained from the naive random walk forecasting rule

charts noise and fundamentals in the london foreign exchange market this paper presents some empirical evidence on the prevalence perceived importance and nature of chartist or technical analysis in the london foreign exchange market if noise traders see e g de long et al i987 are defined as those speculators who do not base their trading strategies on a consideration of market fundamentals then it clearly encompasses those traders who employ chart analysis i e those who base their strategies on the analysis and extrapolation of past price movements alone

the behavior of foreign exchange rates comment the distributors of foreign exchange rates are important for model building and empirical analysis for example many studies have examined foreign exchange market efficiency and currency portfolio management under the assumption that foreign exchange rates are normally distributed the statistical tests in these studies and thus their conclusions may not be reliable if the foreign exchange rates follow non normal distributions realizing the importance of the distribution of exchange rates professors calderon rossell and ben horim 1982 hereafter c b have conducted a study analyzing these distributions based on the skewness of the distribution c b have classified foreign currencies into three groups in the first group the skewness statistic was not significantly different from zero for all currencies and subperiods in the second group the distribution of changes in the foreign exchange rates was close to symmetric except for at least one subperiod in the third group the skewness statistic suggests strongly that all the distributions were asymmetric their results reveal that

how much energy do building energy codes save evidence from california houses regulations governing the energy efficiency of new buildings have become a cornerstone of us environmental policy california enacted the first such codes in 1978 and has tightened them every few years since i evaluate the resulting energy savings three ways comparing energy used by houses constructed under different standards controlling for building and occupant characteristics examining how energy use varies with outdoor temperatures and comparing energy used by houses of different vintages in california to that same difference in other states all three approaches yield estimated energy savings significantly short of those projected when the regulations were enacted

the behavior of foreign exchange rates reply in the preceding comment on our jibs paper 1 three basic claims are made the results in 1 are contrary to those reported elsewhere the contradiction may be due to certain weakness in the methodology employed by us based on a direct approach three currencies out of the fourteen we analyzed are regrouped two the australian dollar and japanese yen from group iii into group i currencies with a symmetric distribution and one the italian lira from group iii into group ii currencies close to have a symmetric distribution except for at least 1 subperiod andthat the arguments presented by us concerning the effects of foreign exchange management policy on exchange rates are no longer supported by the data 1986 jibs journal of international business studies 1986 17 177 180

on the short term predictability of exchange rates a bvar time varying parameters approach abstract in this paper we propose a bayesian vector autoregressive model with time varying parameters bvar tvp to examine the short term predictability of exchange rates an important contribution of the paper is the application of the bvar tvp model for the first time to daily data using information from financial markets another contribution is the production of forecasts in real time at the very short horizon of one trading day ahead typically used by traders and investors in financial markets we employ financial criteria and recently developed statistical tests to assess the exchange rate predictability we find that the bvar tvp model outperforms the random walk for all exchange rates these forecast gains are due primarily to the time variation of coefficients and secondly to information from other financial markets it is shown that international investors could have made statistically significant excess profits if they had followed an inter day trading strategy based on the buy sell signals generated by the model s one day ahead exchange rate forecasts even after allowing for transaction costs and risk factors

a fractional cointegration analysis of purchasing power parity a generalized notion of cointegration called fractional cointegration is introduced to examine the long run purchasing power parity ppp hypothesis by allowing deviations from equilibrium to follow a fractionally integrated process the fractional cointegration analysis can capture a wider range of mean reversion behavior than standard cointegration analyses this gain is flexibility in modeling subtle mean reverting dynamics is found to be important for a proper evaluation of long run ppp empirical results based on historical data for the 1914 1989 period show that ppp reversion exists and can be characterized by a fractionally integrated process in three out of five countries studied the results support ppp as a long run phenomenon though significant short run deviations from ppp can exist

statistical study of foreign exchange rates empirical evidence of a price change scaling law and intraday analysis abstract in this paper we present a statistical analysis of four foreign exchange spot rates against the u s dollar with several million intra day prices over 3 years the analysis also includes gold prices and samples of daily foreign exchange prices over 15 years the mean absolute changes of logarithmic prices are found to follow a scaling law against the time interval on which they are measured this empirical law holds although the distributions of the price changes strongly differ for different interval sizes systematic variations of the volatility are found even during business hours by an intra day analysis of price changes seasonal heteroskedasticity is observed with a period of one day as well as one week as the result of an analogous intra week analysis taking this into account is necessary for any future study of intra day price change distributions and their generating process the same type of analysis is also made for the bid ask spreads

distribution of parallel exchange rates in african countries abstract this paper investigates the distribution of parallel exchange rates in african countries using exploratory data analysis techniques and model fitting stable laws are fitted to empirical distributions using the maximum likelihood estimation method empirical evidence supports the stable hypothesis these distributions are positively skewed and have tails that are much heavier than gaussian counterparts the stable hypothesis is further supported by the converging variance test which suggests that these distributions have infinite variance

mixed diffusion jump process modeling of exchange rate movements this study demonstrates that the mixed diffusion jump process is superior to the stable laws or a mixture of normals as a model of exchange rate changes for the british pound french franc and the we st german mark relative to the united states dollar the parameter value s for the mixed diffusion jump process are dependent on the monetary policy regime in force in the united states with the estimates for the franc and mark being intertemporally similar but different from the pound copyright 1988 by mit press

on jump processes in the foreign exchange and stock markets exchange rates exhibit systematic discontinuities even after allowingfor conditional heteroskedasticity in the diffusion process the results are much more significant in theforeign exchange market than in the stock market which suggests differences in the structure of these markets finally this jump component is shown to explain some of the empirically observed mispricings in the currency options market the objective of this article is to analyze and compare the empirical distribution of returns in the stock market and in the foreign exchange market there are a number of reasons why a better understanding of the stochastic processes driving prices in these markets would be useful many financial models rely heavily on the assumption of a particular stochastic process while relatively little attention is paid to the empirical fit of the postulated distribution as a result models like option pricing models are applied indiscriminately to various markets such as the stock market and the foreign exchange market when the underlying processes may be fundamentally different the foreign exchange market for instance is characterized by active exchange rate man

a model of uk real effective exchange rate behaviour an integrated model of the uk real effective exchange rate is examined which links purchasing power parity with trade flow and asset market mechanisms furthermore time series and econometric analysis using quarterly data from 1972 to 1987 are applied the results obtained are broadly consistent with this model and imply that the uk real effective exchange rate index is constant in the long run

distribution properties of latin american black market exchange rates abstract this paper conducts a statistical analysis of the distribution properties of black market exchange rate changes for 12 latin american currencies the infinite variance stable law hypothesis is tested using a regression type technique to estimate the parameters of the stable paretian distribution strong evidence is found supporting this hypothesis a separate analysis of extreme observations using a robust statistical procedure further supports these findings

banking on currency forecasts how predictable is change in money abstract the paper examines the predictive performance of four structural exchange rate models using both parametric and nonparametric techniques error correction versions of the models are fit so that plausible long run elasticities can be imposed on the fundamental variables of each model a variety of model evaluation statistics are reported our findings confirm that fundamental exchange rate models forecast no better than a random walk model for short term prediction horizons for longer horizons error correction terms can explain exchange rate movements significantly better than a no change forecast for a subset of the models and currencies we consider

fixed versus flexible lessons from ems order flow abstract we extend the literature on regime dependent volatility in two ways first our microstructural model provides a qualitatively new explanation second we test implications of our model using europe s recent shift to rigidly fixed rates ems to emu in the model shocks to order flow induce more volatility under flexible rates because the elasticity of speculative demand is endogenously low leading to pronounced portfolio balance effects new data on ff dm transactions show that order flow had persistent effects on the exchange rate before emu parities were announced after announcement the ff dm rate was decoupled from order flow as the model predicts

measuring business cycle time the business cycle analysis of arthur f burns and wesley c mitchell and the national bureau of economic research presumed that aggregate economic variables evolve on a time scale defined by business cycle turning points rather than by months or quarters do macroeconomic variables appear to evolve on an economic rather than a calendar time scale evidence presented here suggests that they do however the estimated economic time scales are only weakly related to business cycle time scales providing evidence against the view underlying traditional business cycle analysis copyright 1987 by university of chicago press

carbon emissions from the commercial building sector the role of climate quality and incentives commercial buildings play a major role in determining u s greenhouse gas emissions yet surprisingly little is known about the environmental performance of different buildings at a point in time or how the same buildings perform over time by exploiting a unique panel of commercial buildings from a major electric utility we study the association between a building s electricity consumption and the physical attributes of buildings lease incentive terms indicators of human capital and climatic conditions we find that buildings that are newer and of higher quality consume more electricity contrasting evidence for the residential sector however using our panel data set we document that newer buildings are most resilient when exposed to hotter weather those buildings that have a building manager on site and whose tenants face a positive marginal cost for electricity also demonstrate a better environmental performance

an investigation of customer order flow in the foreign exchange market this paper examines the effect that heterogeneous customer orders flows have on exchange rates by using a new propreitary dataset of weekly net order flow segmented by customer type across nine of the most liquid currency pairs we make three contributions first we investigate the extent to which order flow can help to explain exchange rate movements over and above the influence of macroeconomic variables second we look at the usefulness of order flow in forecasting exchange rate movements at longer horizons than those generally considered in the microstructure literature finally we address the question of whether the out of sample exchange rate forecasts generated by order flows can be employed profitably in the foreign exchange markets

meese rogoff redux micro based exchange rate forecasting meese rogoff redux micro based exchange rate forecasting by martin d d evans and richard k lyons this paper compares the true ex ante fore casting performance of a micro based model against both a standard macro model and a random walk in contrast to existing literature which is focused on longer horizon forecasting we examine forecasting over horizons from one day to one month the one month horizon being where micro and macro analysis begin to over lap over our three year forecasting sample we find that the micro based model consistently outperforms both the random walk and the macro model micro based forecasts account for almost 16 percent of the sample variance in monthly spot rate changes these results pro vide a level of empirical validation as yet unat tained by other models the forecasting experiment proposed by richard meese and kenneth rogoff 1983 re mains a benchmark against which exchange rate models are judged their result that structural macro models cannot outperform a naive random walk has proved robust over the decades yet the meese rogoff paper was never about forecasting in the true sense i e using tirrie f information to forecast exchange rates at t 1 b y using concurrent realized values of the forcing variables their regressions were more about concurrent explanation than about ex ante forecasting their only forecast ing element is in their reliance on ex ante data to estimate equation parameters which appro priately penalized models whose estimated pa rameters were unstable tion for the random walk nature of exchange rates is that there exists some unobserved fun damental that itself follows a random walk un observed being important because fundamentals proposed in most macro models do not follow random walks they offer a different explana tion one rooted in the asset approach to ex change rates and the present value relation that follows from it specifically they show that i f fundamentals are 1 1 but not necessarily ran dom walks then as the discount factor in the present value relation approaches 1 the ex change rate will follow a process arbitrarily close to a random walk intuitively given that an 1 1 process can be split into random walk and stationary components a discount factor near 1 means that most all of the weight is placed on fundamentals far into the future ex pectations of which are dominated by the random walk component charles engel and kenneth west 2004 2005 provide a valuable perspective on the forecastability of exchange rates one explana this paper takes the analysis of engel and west as an important reorientation of thinking and brings it to the natural next step specifi cally if there is little room for forecasting based on stationary components of fundamentals then one needs to focus on where all the action is namely exchange rate dynamics that come from expectational surprises though the sur prise part is by definition orthogonal to public information our micro based model shows that there should exist types of nonpublic infor mation that are useful for forecasting this part and where to look for these types of informa tion we then locate data on these types of nonpublic information and test whether they have true ex ante forecasting power we should evans department of economics georgetown uni versity washington dc 20057 and nber lyons haas school of business university of california berkeley c a 94720 1900 and nber we are grateful to ken west for his comments and to the national science foundation for financial support we refrain from using the word news because it has too strong an association with macro information that is public which even in the most careful of event studies explains less than 5 percent of exchange rate variation in total see torben andersen et al 2003

empirics on the long run effects of building energy codes in the housing market we study the effectiveness of building energy codes taking a long run perspective the focus is on regulation s impact on energy demand in both high and low quality residences in other words the diffusion and the entry of green buildings in the housing market we develop a measure for regulation intensity and apply this to a panel error correction regression model for energy requirements of a large sample of german apartment houses built between 1950 and 2005 we show that regulation is effective in saving energy in particular regulation pushes investors in the low quality housing market segment toward the technological frontier indirectly it also affects the high quality segment jel q41 r52

the mystery of the multiplying marks a modification of the monetary model fair ray and dwight jaffee methods of estimation for markets in disequilibrium econometrica 40 may 1972 497 514 fair ray and harry kelejian methods of estimation for markets in disequilibrium further study econometrica 42 jan 1974 177 190 goldfeld stephen and richard quandt estimation in a disequilibrium model and the value of information journal of econometrics 3 nov 1975 325 348 hausman jerry the effects of wages taxes and fixed costs on women s labor force participation journal of public economics 14 oct 1980 161 194 mcdonald john and robert moffitt the uses of tobit analysis this review 62 may 1980 318 321 maddala g s and forrest nelson maximum likelihood methods for models of markets in disequilibrium econometrica 42 nov 1974 1013 1030 moffit robert and kenneth kehrer the effect of tax and transfer programs on labor supply the evidence from the income maintenance experiments in ronald ehrenberg ed research in labor economics vol 4 greenwich conn jai press 1981 nelson forrest censored regression models with unobserved stochastic censoring thresholds journal of econometrics 6 nov 1977 309 327 oi walter labor as a quasi fixed factor journal of political economy 70 dec 1962 538 555 rosen harvey and richard quandt estimation of a disequilibrium aggregate labor market this review 60 aug 1978 371 379 tobin james estimation of relationships for limited dependent variables econometrica 26 jan 1958 24 36