On consistent testing for serial correlation in seasonal time series models

The author considers serial correlation testing in seasonal time series models. He proposes a test statistic based on a spectral approach. Many tests of this type rely on kernel-based spectral density estimators that assign larger weights to low order lags than to high ones. Under seasonality, however, large autocorrelations may occur at seasonal lags that classical kernel estimators cannot take into account. The author thus proposes a test statistic that relies on the spectral density estimator of Shin (2004), whose weighting scheme is more adapted to this context. The distribution of his test statistic is derived under the null hypothesis and he studies its behaviour under fixed and local alternatives. He establishes the consistency of the test under a general fixed alternative. He also makes recommendations for the choice of the smoothing parameters. His simulation results suggest that his test is more powerful against seasonality than alternative procedures based on classical weighting schemes. He illustrates his procedure with monthly statistics on employment among young Americans.     

DOES THE BETTER‐THAN‐AVERAGE EFFECT SHOW THAT PEOPLE ARE OVERCONFIDENT?: TWO EXPERIMENTS

We conduct two experimental tests of the claim that people are overconfident, using new tests of overplacement that are based on a formal Bayesian model. Our two experiments, on easy quizzes, find that people overplace themselves. More precisely, we find apparently overconfident data that cannot be accounted for by a rational population of expected utility maximizers who care only about money. The finding represents new evidence of overconfidence that is robust to the Bayesian critique offered by Benoît and Dubra (Jean‐Pierre Benoît and Juan Dubra (2011). “Apparent Overconfidence.” Econometrica, 79, 1591–1625). We discuss possible limitations of our results.     

Influence of Routine Slaughtering on the Evolution of BSE: Example of British and French Slaughterings

The aim of this article is to build a methodology allowing the study and the comparison of the potential spread of BSE at the scale of countries under different routine slaughtering conditions in order to evaluate the risk of nonextinction due to this slaughtering. We first model the evolution in discrete time of the proportion of animals in the latent period and that of infectives, assuming a very large branching population not necessarily constant in size, two age classes, less than 1-year-old animals, and adult animals. We analytically derive a bifurcation parameter rho(0) allowing us to predict either endemicity or extinction of the disease, which has the meaning of an epidemiological reproductive rate. We show that the classical reproductive number R(0) cannot be used for prediction if the size of the population, when healthy, does not remain stable throughout time. We illustrate the qualitative results by means of simulations with either the British routine slaughtering probabilities or the French ones, the other conditions being assumed identical in both countries. We show that the French probabilities lead to a higher risk of spread of the disease than the British ones, this result being mainly due to a smaller value of the routine slaughtering probability of the adult animals in France than in Great Britain.     

The limiting distribution of the least-squares estimator in nearly integrated seasonal models

We consider the least-squares estimator of the autoregressive parameter in a nearly integrated seasonal model. Building on the study by Chan (1989), who obtained the limiting distribution, we derive a closed-form expression for the appropriate limiting joint moment generating function. We use this function to tabulate percentage points of the asymptotic distribution for various seasonal periods via numerical integration. The results are extended by deriving a stochastic asymptotic expansion to order O_p(T^-l), whose percentage points are also obtained by numerically integrating the appropriate limiting joint moment generating function. The adequacy of the approximation to the finite-sample distribution is discussed.     

Global Financial Crisis, Public Administration and Governance: Do New Problems Require New Solutions?

A financial crisis, or any crisis, is likely to produce a variety of responses from governments. This article discusses the range of responses that may be possible, pointing out that diametrically opposite answers may be made to the common problem. The analysis points to the persistence of many dichotomies in our thinking about public administration and public policy. These varied responses to crises are investigated in several political systems including the Baltic States and the European Union.     

Reflexive audiovisual methodology: The emergence of “minority practices” among pluriactive stock farmers

This paper proposes a new way for sociology, through both methodology and theory, to understand the reality of social groups and their “minority practices.” It is based on an experiment that concerns a very specific category of agriculturalists called “pluriactive” stock farmers. These stock farmers, who engage in raising livestock part-time alongside another full-time job, form a minority category within the agricultural profession.We address the question of how to analyze and represent the practices of this kind of “social” group or category through participatory filmmaking. Our research shows that beyond the collaborative production and screening of the film done in close cooperation with the stock farmers themselves, a second unexpected dynamic emerged around the sequences that were cut in the final editing round. These cut sequences reveal hesitations and disagreements among the breeders about their own practices in relation to their work and to animal welfare. These hesitations are not considered weaknesses, but rather as proof of the emergence of this group of stock farmers as “practitioners”. In the realm of intervention research, the participatory film-making process is attractive because it enables the farmers to raise new questions on their own, discuss them, and eventually resolve them, while also encouraging the researchers to identify the conditions that must be met in order to achieve this fragile linkage. This process and its outcomes force us to revisit the theoretical question of what constitutes a pragmatic definition of a “practice.”     

Measuring State TANF Policy Variations and Change After Reform*

Objectives. Our objectives are to describe the policies adopted after PRWORA, which vary across states, to test for common underlying policy concepts, demonstrating how these policies are interrelated, and to examine whether policy stringency diffused to neighboring states results in greater policy stringency across all states over time. We convert textual TANF welfare guidelines into empirically derived policy dimensions and use the derived quantitative scores to describe variation and change in welfare policy dimensions across status during the 1996–2003 post‐welfare‐reform period. Methods. Utilizing the Urban Institute's Welfare Rules Database, we apply a factor analytic methodology to 78 unique state policy guidelines that were coded on a lenient‐to‐stringent continuum. Regression analyses, employing spatial contiguity weighting, are used to describe policy diffusion. Results. The results identified 15 underlying first‐order post‐welfare‐reform policy dimensions, which for scientific parsimony were further reduced to three second‐order underlying dimensions representing rules governing eligibility: eligibility requirements for groups, behavioral responsibilities for maintaining eligibility, and eligibility time limits and exemptions. Analysis of the quantitative scores showed that by 2003 states had become more lenient regarding eligibility criteria for groups but decidedly more stringent regarding behavioral guidelines for maintaining eligibility and eligibility time limits and exemptions. Spatial clustering is not found globally but is significant for some states at the local level. Spatial diffusion is apparent only for behavioral rules. Conclusions. Our results suggest that TANF policy variations across states go beyond payment levels to include salient eligibility rules. The patterns of variability in change scores across states do not support a pervasive “race to the bottom” conclusion.     

Correction to: Coping with climatic shocks: local perspectives from Haiti’s rural mountain regions

Population and Environment - The article Coping with climatic shocks: local perspectives from Haiti’s rural mountain regions, written by Caroline Staub, Anne Gilot, Molene Pierre, Gerald...     

On the Usefulness or Lack Thereof of Optimality Criteria for Structural Change Tests

Elliott and Müller (2006) considered the problem of testing for general types of parameter variations, including infrequent breaks. They developed a framework that yields optimal tests, in the sense that they nearly attain some local Gaussian power envelop. The main ingredient in their setup is that the variance of the process generating the changes in the parameters must go to zero at a fast rate. They recommended the so-called qL?L test, a partial sums type test based on the residuals obtained from the restricted model. We show that for breaks that are very small, its power is indeed higher than other tests, including the popular sup-Wald (SW) test. However, the differences are very minor. When the magnitude of change is moderate to large, the power of the test is very low in the context of a regression with lagged dependent variables or when a correction is applied to account for serial correlation in the errors. In many cases, the power goes to zero as the magnitude of change increases. The power of the SW test does not show this non-monotonicity and its power is far superior to the qL?L test when the break is not very small. We claim that the optimality of the qL?L test does not come from the properties of the test statistics but the criterion adopted, which is not useful to analyze structural change tests. Instead, we use fixed-break size asymptotic approximations to assess the relative efficiency or power of the two tests. When doing so, it is shown that the SW test indeed dominates the qL?L test and, in many cases, the latter has zero relative asymptotic efficiency.