On the missing equation: Comment

Canto and Miles (CM) present and analyze graphically “a third, alternative method for closing the IS-LM system of equations”—the ‘wedge model’. According to CM, “the result is a more general set of results” and “the two traditional alternatives are only special cases.” The CM model, however, is logically inconsistent. Because CM implicitly assume simultaneous capital market equilibrium and disequilibrium, CM's assumptions are mutually inconsistent. Thus, none of the reported results logically follow. Furthermore, the CM model is not very general. This paper proves analytically that GNP is determined without the IS and LM equations both in the CM model and in the obvious logical patchups of the CM model. Therefore, for example, in the CM model exogenous changes in business-fixed investment or consumption have no predicted effect on national income.     

On the missing equation: A reply

Shaller's criticism of our paper improperly interprets our model. Furthermore, his proof either assumes that the aggregate supply and demand curves are identical, or ignores that factor market demand already incorporates aggregate demand.     

Poverty analysis with missing data: alternative estimators compared

Poverty models are generally estimated by using sample surveys affected by missing data problems. Most methods proposed to take account of missing data problems consider point estimators which typically impose restrictive assumptions. However, it is possible to identify a range of logically possible values for the poverty probability, an identification interval, without imposing any assumption. It is then of interest to check whether the point estimates lie within the identification interval. This is a way to check the validity of the assumptions imposed by point estimators. Using the ECHP we perform this check to assess different estimation methods.     

The labor wedge: MRS vs. MPN

Do fluctuations of the labor wedge, defined as the gap between the firm's marginal product of labor (MPN) and the household's marginal rate of substitution (MRS), reflect fluctuations of the gap between the MPN and the real wage or fluctuations of the gap between the real wage and the MRS? For many countries and most forcefully for the United States, fluctuations of the labor wedge predominantly reflect fluctuations of the gap between the real wage and the MRS. As a result, business cycle theories of the labor wedge should primarily focus on improving the household side of the labor market. Explanations of the labor wedge based on departures of the representative firm's MPN from the real wage are rejected by the data because the labor share of income is not strongly procyclical.     

Price dynamics in an input-output model: An alternative approach

The suggested approach is developed, on the basis of firms' markup behaviour, in terms of current prices making value coefficients change as the effects of the initial price rise spread through the economy.     

Discrimination between alternative arima model specifications

Summary The use of ARIMA models in applied economic forecasting has become more and more popular in recent years. In order to secure a good forecasting performance of these models, great care should be spent on the correct identification and the efficient estimation of models of this type.The present paper deals with problems often encountered in applied time series analysis. When fitting an ARIMA model to an observed macroeconomic time series, it might be detected that several models seem to represent this series equally well. The problem here is how to discriminate between alternative ARIMA model specifications representing the same macroeconomic time series.In the first part of the paperthe theoretical concepts, used in the identification and estimation of an ARIMA model, are briefly reviewed. In the second part, these techniques are then applied in a case-study in order to obtain ARIMA models for private consumer expenditure and disposable personal income.

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Zusammenfassung Die vorliegende Arbeit beschäftigt sich mit einigen Problemen der angewandten Zeitreihen-analyse. Beim Versuch, ein ARIMA-Modell für beobachtete makroökonomische Zeitreihen zu schätzen, entdeckt man bisweilen, daß mehrere Modelle die Zeitreihe gleich gut zu repräsentieren scheinen. Hier stellt sich dann die Frage, ob es verläßliche Kriterien gibt, die eine Auswahl aus alternativen Modellansätzen gestatten. Im ersten Teil der Arbeit werden kurz die Konzepte, die für die Identifikation und Schätzung von ARIMA-Modellen zur Verfügung stehen, dargestellt. Der zweite Teil stellt eine Fallstudie dar, in der ARIMA-Modelle für den privaten Konsum und das verfügbare persönliche Einkommen entwickelt werden.

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I would like to thankJohannes Ledolter from the University of Iowa for his very helpful comments on an earlier draft of this paper.     

Using the gravity equation to differentiate among alternative theories of trade

The simple gravity equation explains a great deal about the data on bilateral trade flows and is consistent with several theoretical models of trade. We argue that alternative theories nevertheless predict subtle differences in key parameter values, depending on whether goods are homogeneous or differentiated and whether or not there are barriers to entry. Our empirical work for differentiated goods delivers results consistent with the theoretical predictions of the monopolistic-competition model, or a reciprocal-dumping model with free entry. Homogeneous goods are described by a model with national (Armington) product differentiation or by a reciprocal-dumping model with barriers to entry. JEL Classification: F10, F12
Equation de gravité et différenciation entre diverses théories du commerce international. La simple équation de gravité fournit une bonne part d'explication des flux de commerce bilatéraux et donne des résultats compatibles avec plusieurs modèles de commerce international. Les auteurs suggèrent que les diverses théories prédisent néanmoins des différences subtiles dans les valeurs de paramètres clés, selon que les biens sont homogènes ou différenciés, et qu'il y a barrières ou non à l'entrée. Le travail empirique des auteurs livre des résultats compatibles avec les prévisions théoriques du modèle de concurrence monopolistique ou du modèle de dumping réciproque avec entrée libre. On décrit les flux de biens homogènes à l'aide d'un modèle de différenciation nationale de produit à la Armington ou par un modèle de dumping réciproque avec barrières à l'entrée.     

The missing shock: the macroeconomic impact of British Privatizations

In this paper the impact of privatization on macroeconomic performance in the United Kingdom is tested using quarterly data from 1979 to 1999. Privatization proceeds have been included in a simple analytical framework dealing with both demand and supply-side of the economy. Multivariate cointegration techniques have been used in order to consider the nonstationarity of the time series involved. The empirical results show that privatizations have no long-run effects on output in the UK. This result is consistent with microeconomic evidence that shows that in the UK ownership change per se had little impact on long term productivity trends. Moreover it is found that privatization proceeds have contributed to sustaining public expenditures.     

The estimation of a hedonic asking and offer rent equation model: An EM algorithm approach

In this paper we claim that modeling housing markets, specifically the rental housing market, should be based on some sort of disequilibrium framework. We posit a model of asking and offer rents in the spirit of a sample selectivity model. This approach allows us not only to test whether landlords and tenants agree upon the marginal evaluations of unit attributes, but also to estimate the impact on rental demand of tenant specific attributes such as family income and race. Since estimators obtained from this procedure are consistent, but not efficient in this two equation context, we employ an EM algorithm in our estimation in order to obtain MLE equivalent estimators. We have found that our data support the use of this disequilibrium approach in that the coefficient estimates for the asking rent equation, under the assumptions of a sample selectivity model, are not coincident with those obtained from an uncorrected equation.     

The labor wedge as a matching friction

We use a search and matching model to decompose the labor wedge into three classes of labor market frictions and evaluate their role for the labor wedge and unemployment. We find that there is an asymmetric effect of labor market frictions on the labor wedge and unemployment. While the wedge is to a large extent explained by changes in matching efficiency, unemployment is accounted for by the combination of frictions to matching efficiency, job destruction and bargaining. If search and matching frictions give rise to the labor wedge, then it is relevant for explaining unemployment mainly through changes in matching efficiency.     

Smuggling around the world: evidence from a structural equation model

This article uses a Multiple Indicators Multiple Causes (MIMIC) model to analyse the determinants of smuggling. The analysis reveals that higher corruption and a lower rule of law encourage smuggling. Tariffs and trade restrictions are important push factors, while a higher Black Market Premium (BMP) discourages smugglers. Based on the MIMIC estimates, we calculate an index of smuggling which provides a ranking for 54 countries. We find that smuggling is rampant in Cameroon, Pakistan and Kenya while it is least prevalent in Switzerland, Finland and Sweden.     

The missing piece: Valuing averting behavior for children's ozone exposures

Individuals can reduce their exposure to air pollution by reducing the amount of time they spend outdoors. Reducing outdoor time is an example of an averting behavior that should be measured as part of willingness to pay (WTP) for improvements in air quality. In this paper, we estimate parents’ WTP to prevent restrictions on a child's outdoor time from a stated-preference (SP) conjoint survey. We combine this WTP measure with an estimate of reductions in time spent outdoors on high-ozone days from an activity-diary study to estimate this averting behavior component of WTP for reductions in ozone pollution.     

The proper panel econometric specification of the gravity equation: A three-way model with bilateral interaction effects

We argue that the proper specification of a panel gravity model should include main (exporter, importer, and time) as well as time invariant exporter-by-importer (bilateral) interaction effects. In a panel of 11 APEC countries, the latter are highly significant and account for the largest part of variation. First version received: February 2001/Final version received: June 2002 RID="*" ID="*"  We are grateful to two anonymous referees and Robert Kunst for their helpful comments.     

The Load Model: an alternative to QALY

Background: QALYs are widely used in health economic evaluation, but remain controversial, largely because they do not reflect how many people behave in practice. This paper presents a new conceptual model (Load Model) and illustrates it in comparison with the QALY model.

Methods: Load is the average annual weight attributed to morbidity and mortality over a defined period, using weightings based on preference judgements. Morbidity Load is attributed to states of illness, according to their perceived severity. When people are in full health, Load is zero (no morbidity). Death is treated as an event with negative consequences, incurred in the year following death. Deaths may be weighted equally, with a fixed negative weight such as ?100, or differ according to the context of death. After death, Load is zero. In a worked example, we use the standard gamble method to obtain a weighting for an illness state, for both Load and QALY models. A judge is indifferent between certainty of 1.5 years’ illness followed by death, or a 50/50 chance of 1.5 years’ full health or 1-year illness, each followed by death. The weightings calculated are applied to a hypothetical life, 72 years in full health followed by 3 years with illness then death, using both models. Three other hypothetical outcomes are also compared.

Results: For an example life, the relative size of the morbidity component compared with the mortality component is much higher in the Load model than in the QALY model. When comparing alternative outcomes, there are also substantial differences between the two models.

Conclusions: In the Load model the weight of morbidity, relative to mortality, is very different from that in the QALY model. Given the role of the QALYs in economic evaluation, the implications of an alternative, which generates very different results, warrant further exploration.