Statistical Decision Problems and Bayesian Nonparametric Methods

This paper considers parametric statistical decision problems conducted within a Bayesian nonparametric context. Our work was motivated by the realisation that typical parametric model selection procedures are essentially incoherent. We argue that one solution to this problem is to use a flexible enough model in the first place, a model that will not be checked no matter what data arrive. Ideally, one would use a nonparametric model to describe all the uncertainty about the density function generating the data. However, parametric models are the preferred choice for many statisticians, despite the incoherence involved in model checking, incoherence that is quite often ignored for pragmatic reasons. In this paper we show how coherent parametric inference can be carried out via decision theory and Bayesian nonparametrics. None of the ingredients discussed here are new, but our main point only becomes evident when one sees all priors—even parametric ones—as measures on sets of densities as opposed to measures on finite-dimensional parameter spaces.     

Output gap in Brazil: a real-time data analysis

Recent literature for developed economies has shown that output gap estimates go through important revisions over time, impairing their reliability in real time. We organize a real-time data set for Brazil’s GDP and assess the revisions of the output gap estimated by four different methods. Similar to the findings of studies for developed economies, the output gap revisions in Brazil are substantial in all methods, with frequent changes in the output gap sign. In general, both the GDP data revision and the effect of adding new observations to the sample are relevant sources of output gap revisions. However, differently from those studies, we cannot assert that the latter source is preponderant.     

Technical efficiency analysis correcting for biases from observed and unobserved variables: an application to a natural resource management project

This article brings together the stochastic frontier framework with impact evaluation methodology to compare technical efficiency (TE) across treatment and control groups using cross-sectional data associated with the MARENA Program in Honduras. A matched group of beneficiaries and control farmers is determined using propensity score matching techniques to mitigate biases stemming from observed variables. In addition, possible self-selection arising from unobserved variables is addressed using a selectivity correction model for stochastic frontiers recently introduced by Greene (J Prod Anal 34:15?C24, 2010). The results reveal that average TE is consistently higher for beneficiary farmers than the control group while the presence of selectivity bias cannot be rejected. TE ranges from 0.67 to 0.75 for beneficiaries and from 0.40 to 0.65 for the control depending on whether biases were controlled or not. The TE gap between beneficiaries and control farmers decreases by implementing the matching technique and the sample selection framework decreases this gap even further. The analysis also suggests that beneficiaries do not only exhibit higher TE but also higher frontier output.     

“国际旅游岛”背景下海南省高校休闲体育专业建设的思考

以海南国际旅游岛建设为背景,对海南省高校休闲体育专业建设进行初步探讨。通过分析海南省体闲体育发展趋势特征,提出海南省高校休闲体育专业的人才培养目标、培养规格,课程体系设置和专业方向设置的建议;探讨在教育培养方案、专业课程知识体系、专业教材和教师方面的制约瓶颈,以期望海南高校为国际旅游岛休闲体育产业培养相关优秀的专业人才。     

Do stable strategic time periods exist? Towards new methodological and theoretical insights

This paper investigates a fundamental issue in the current research on strategic groups: the existence or non‐existence of the so‐called ‘stable strategic time periods’ (SSTPs). Our study provides new evidence by adding new methodological and theoretical insights. The research setting is the Spanish banking industry over a 15‐year period, 1983–1997. Unlike all prior longitudinal research that found SSTPs, the multi‐method procedure that we used in this study (i.e. equality of variance and covariance matrix and mean vector of strategic variables and a subsequent grouping analysis performed through the MCLUST) has led us to reject the existence of SSTPs in the industry under study. Based on these original findings, we conclude by suggesting a proposition which should be corroborated in future empirical studies on strategic groups. Copyright © 2007 John Wiley & Sons, Ltd.     

Homogeneity tests in meta-analysis: a Monte Carlo comparison of statistical power and Type I error

The statistical power and Type I error rate of several homogeneity tests, usually applied in meta-analysis, are compared using Monte Carlo simulation: (1) The chi-square test applied to standardized mean differences, correlation coefficients, and Fisher's r-to-Z transformations, and (2) S&H-75 (and 90 percent) procedure applied to standardized mean differences and correlation coefficients. Chi-square tests adjusted correctly Type I error rates to the nominal significance level while the S&H procedures showed higher rates; consequently, the S&H procedures presented greater statistical power. In all conditions, the statistical power was very low, particularly when the sample had few studies, small sample sizes, and presented short differences between the parametric effect sizes. Finally, the criteria for selecting homogeneity tests are discussed.     

The gender wage gap in Austria: eppur si muove!

We examine the change of the gender wage gap in Austria between 2002 and 2007 using Juhn et al. (Workers and their wages, AEI Press, Washington DC, pp 107–143, 1991) decomposition. We analyze data from Austrian tax records which we merge with social security records and Austrian micro-censuses of the years 2002 and 2007. We find that the gender wage gap declined from 21 % in 2002 to 18 % in 2007. The main determinant of this decline is the relative improvement of women’s unobserved characteristics. The decline of the gender wage gap is also due to women having attained more formal education and to a convergence of men’s and women’s returns to education. Women’s improved educational attainments were partly offset by a shift in the demand for skilled workers that disadvantaged unskilled workers, most of whom are women, resulting in a moderate decrease of the gender pay gap over these years. Robustness checks confirm our results.     

Pass-through in dollarized countries: should Ecuador abandon the US dollar?

In this article, we examine the convenience of dollarization for Ecuador today. As Ecuador is strongly integrated financially and commercially with the United States, the exchange rate pass-through should be zero. However, we sustain that rising rates of imports from trade partners other than the United States and subsequent real effective exchange rate depreciations are causing the pass-through to move away from zero. Here, in the framework of the Vector Error Correction Model, we analyse the impulse response function and variance decomposition of the inflation variable. We show that the developing economy of Ecuador is importing inflation from its main trading partners, most of them emerging countries with appreciated currencies. We argue that if Ecuador recovered both its monetary and exchange rate instruments, it would be able to fight against inflation. We believe such an analysis could be extended to other countries with pegged exchange rate regimes.     

Evaluating the economy embedded in the Brazilian ethanol–gasoline flex-fuel car: a Real Options approach

The introduction of the flex-fuel cars in the Brazilian market in 2003 changed considerably the consumer decision-making process. Prior to this date, it was necessary to choose the automobile type only by gasoline or by ethanol fuel; today it is possible to choose a car type with both fuel options. This flexibility generates economic advantages for his owner, but what are the financial benefits of a flex-fuel car in comparison with a car using only gasoline? Geographically, where is the owner of the benefits from this flexibility located? This article presents an empirical application of the Real Options Theory in the analysis of the flex-fuel car option for five geographic Brazilian regions: Northern, Northeastern, Central-Western, Southeastern and Southern. The regional price differences as well as the consumer preferences of these regions were met. For this purpose, historical fuel prices were considered stochastic and following a Mean Reverting Stochastic process. The prediction and option values were generated by a Monte Carlo simulation. The results indicated that the option embedded on the Brazilian flex-fuel car adds considerable value to the owner in all regions and car models considered, with the Southeastern Region receiving most benefits by the flex option.     

Periodograms on fiscal illusion: discussing the cycle lengths of public finances in European countries

In this article, we study the duration of public finance cycles in 12 European countries since 1960. We applied periodogram techniques on the levels of fiscal illusion found for these established democracies and tested the statistical significance of the Fourier frequency peaks. Our empirical efforts revealed that most of the cycles in these countries could be characterized as long-term cycles (approximately 30 years), embodying subcycles of approximately 15 years. These findings show that in addition to the commonly studied electoral cycles or real business cycles, our democracies demonstrate extended public finance cycles that extend over various legislative tenures ruled by different political parties.