CAUSALITY BETWEEN PRODUCTIVITY AND EXPORTS IN AGRICULTURE: EVIDENCE FROM ASIA AND LATIN AMERICA

This paper examines the causal relationship between agricultural productivity and exports for selected Asian and Latin American countries. Alternative views about the causal relationship between these variables of economic interest exist. Economic theory provides no firm basis to judge whether productivity causes exports or exports cause productivity (export-led growth). Since this issue is empirical, econometric tests are utilised to investigate the nature of this causality. Test results are mixed although the export-led growth hypothesis is validated in a few cases.     

Regional unemployment in Spain: Disparities,business cycle and wage setting

The existence and persistence of regional disparities in the unemployment rate is a common problem of many European economies. However, in Spain, this situation exhibits a characteristic feature: a strong positive relationship with the business cycle. The analysis in this paper investigates the relationship between this distinguishing feature of the Spanish economy and changes in the regional wage-setting mechanism, and how this relationship has influenced the aggregate Spanish labour market performance in the recent past. The empirical finding of an important regional imitation effect in wage bargaining may explain both the persistence of disparities, and the positive relationship between regional unemployment dispersion and the business cycle. This result has a direct implication for employment policies, which must take into account the regional dimension of the unemployment problem.     

Modeling weekly Canary tomato exports

The European tomato market is characterized by a constant process of dynamic adjustment towards equilibrium. Furthermore, Canary Island tomato exports cause a high seasonal impact on market prices in the winter period. In these circumstances, an adequate distribution of weekly shipments throughout the year could contribute to maximize producers' profits. Moreover, Canary export levels show some degree of instability, clearly related to the changes in the EU trade rules and there is a long period, in the summer, without exports. The aim of this article is to analyze the long‐term movements and, particularly, the seasonal pattern of Canary Island tomato exports throughout the last two decades. To observe more clearly the exporter's decisions, weekly data have been used. The instabilities in the long‐term behavior of the series and the specific nature of the seasonal pattern should be taken into account, to capture the performance of exports accurately. Thus, this analysis is carried out using the structural approach to time series analysis, and the usefulness of spline functions as a tool capable of modeling seasonal variations for which the period does not remain the same over time is shown.     

Private school vouchers and student achievement: A fixed effects quantile regression evaluation

Fundamental to the recent debate over school choice is the issue of whether voucher programs actually improve students' academic achievement. Using newly developed quantile regression approaches, this paper investigates the distribution of achievement gains in the first school voucher program implemented in the US. We find that while high-performing students selected for the Milwaukee Parental Choice program had a positive, convexly increasing gain in mathematics, low-performing students had a nearly linear loss. However, the program seems to prevent low-performing students from having an even bigger loss experienced by students in the public schools.     

Automobile demand,model cycle and age effects

This paper is aimed at exploring the existence of typical patterns of automobile model life and the formal test for age effects in a discrete-choice demand framework estimated with data on the models sold in the Spanish market. Estimates show that the evolution of market shares entails and quantifies age effects resulting from consumer demand. These effects are clearly distinguishable from the impacts generated by changes in attributes and firm pricing. They carry an exogenous factor that is full of implications for firm behaviour over the life of a model: the modification of demand price sensitivities. As a result, for example, equilibrium own-price elasticities are observed to decrease until the fourth year of a model life, and then to increase again.      

Uninsured idiosyncratic risk, liquidity constraints and aggregate fluctuations

Summary. I study the role played by uninsured idiosyncratic risk and liquidity constraints in the propagation of aggregate fluctuations. To this purpose, I compare the aggregate fluctuations of two model economies that differ in their insurance technologies only. In one of these model economies liquidity constrained households vary their holdings of a nominally denominated asset in order to buffer an uninsured idiosyncratic shock to their individual production opportunities. In the other economy every idiosyncratic component of risk can be costlessly insured. I find that the limited insurance technology implies fluctuations in output that are 20% larger, fluctuations in hours relative to output that are 9% larger, fluctuations in consumption relative to output that are 18% smaller, and a correlation of hours and productivity that is 15% smaller than those that obtain under the full insurance technology. Received: March 6, 1996; revised version August 15, 1996     

The persistence of abnormal returns at industry and firm levels: Evidence from Spain

We apply structural equation models to longitudinal data on profits of firms within industries to study the persistence of abnormal returns. We obtain a two‐way variance decomposition for abnormal returns: at firm vs. industry levels, and at permanent vs. transitory components. This decomposition enables us to assess the relative importance of the fundamental components of abnormal returns discussed in the literature. The method is applied to a panel of 5,000 Spanish firms observed over the period 1995–2000. We conclude that: (a) there are significant and permanent differences between profit rates at both industry and firm levels; (b) variation of abnormal returns at firm level is greater than at industry level; and (c) firm and industry levels do not differ significantly regarding rates of convergence of abnormal returns. Copyright © 2007 John Wiley & Sons, Ltd.     

An Assessment of Basel II Procyclicality in Mortgage Portfolios

In this paper we develop a probability of default (PD) model for mortgage loans, taking advantage of the Spanish Credit Register, a comprehensive database on loan characteristics and credit quality. From that model, we calculate different types of PDs: point in time, PIT, through the cycle, TTC, average across the cycle and acyclical. Then, we compare capital requirements coming from the different Basel II approaches. We show that minimum regulatory capital under Basel II can be very sensitive to the risk measurement methodology employed. Thus, the procyclicality of regulatory capital requirements under Basel II is an open question, depending on the way internal rating systems are implemented and their output is utilised. We focus on the mortgage portfolio since it is one of the most under researched areas regarding the impact of Basel II and because it is one of the most important of banks’ portfolios.     

A Comparison of χ2, RFA and IRT Based Procedures in the Detection of DIF

Bias research began at the end of the 1960s anddeveloped rapidly in the following decades for obvioussocial and political reasons, and due to the importantimpact that this issue has on the field ofpsychological and educational measurement. Since then,several methods have been proposed for the study anddetection of item bias or differential itemfunctioning (DIF). This paper presents a simulationstudy comparing the potential of some of these methodsfor detecting DIF: two IRT-based techniques (area measures), three ²-based procedures (MantelHaenszel, Logit Model and Logistic Regression) and theRestricted Factor Analysis method. The results showthat the technique that appears to do the best job isthe Mantel Haenszel statistic. Moreover, all detectiontechniques tend to overidentify DIF items, that is,some of the items labeled with DIF may in fact bewithout DIF. This tendency is slightly reversed in theLogistic Regression procedure.