The Time Series and Cross‐Section Asymptotics of Dynamic Panel Data Estimators

In this paper we derive the asymptotic properties of within groups (WG), GMM, and LIML estimators for an autoregressive model with random effects when both T and N tend to infinity. GMM and LIML are consistent and asymptotically equivalent to the WG estimator. When T/N→ 0 the fixed T results for GMM and LIML remain valid, but WG, although consistent, has an asymptotic bias in its asymptotic distribution. When T/N tends to a positive constant, the WG, GMM, and LIML estimators exhibit negative asymptotic biases of order 1/T, 1/N, and 1/(2N−T), respectively. In addition, the crude GMM estimator that neglects the autocorrelation in first differenced errors is inconsistent as T/N→c>0, despite being consistent for fixed T. Finally, we discuss the properties of a random effects pseudo MLE with unrestricted initial conditions when both T and N tend to infinity.     

Exposure to Traffic and Risk of Hospitalization Due to Injuries

Research on the risk of motor vehicle injuries and their relationship with the amount of travel has been only partially analyzed. The few individual exposure assessments are related to very specific subsets of the driving and traveling populations. This study analyzes the relationship between kilometers traveled and hospitalization due to motor vehicle injuries. Twelve thousand three hundred and sixty nine Spanish university graduates from the Seguimiento Universidad de Navarra multipurpose cohort study were evaluated. They had not been hospitalized due to motor vehicle injuries at baseline and were followed up to eight years. Biannual questionnaires allowed for self‐reporting of kilometers traveled in motor vehicles, together with incidence of hospitalization. Covariates in the Cox regression models included age and gender and baseline use of safety belt while driving, driving a vehicle with driver‐side airbag, driving a motorcycle, and drinking and driving. There were 49,766 participant‐years with an average yearly travel of 7,828 km per person‐year. Thirty‐six subjects reported a first hospitalization event during this time. The adjusted hazard ratio per additional kilometer traveled was 1.00005 (95% confidence interval 1.000013 to 1.000086). Even the smallest of reductions in the amount of kilometers traveled (from an average of 3,250 km per year to 1,000) has a statistically significant protective effect on the likelihood of sustaining hospitalization due to motor vehicle injury (aHR 0.9, 95% CI 0.78 to 0.98). In light of current policies aimed to reduce motorized traffic due to environmental concerns, it may be appropriate to consider the additional health benefit related to reductions in injuries.     

Afterword. Going Granular

Qualitative Sociology - The articles in this special issue demonstrate that ethnography is an unparalleled way of penetrating and making sense of what the state is and does, of how ordinary...     

Structure and composition of woody plants in urban forest remnants with different adjacent land-use and slope aspect

The plant community in the karst forest is influenced by mesoclimatic conditions, such as temperature and humidity and these conditions are in turn influenced by topographic features. Urban areas adjacent to karstic forest remnants also have the potential to influence mesoclimatic variables and may serve as a source of exotic species. We described the temperature and relative humidity of karstic forest remnants at slopes with combinations of either southeast (SE) or northwest (NW) aspect, and adjacent to either urban (URB) or secondary forest (SF). We also compared forest structure and composition on these slopes to understand the interaction between forest aspect and adjacent land use on the plant community. URB-SE slopes had highest temperature and lowest humidity among all adjacent land use-aspect combinations. Understory species in SE slopes had similar richness and diversity independently of adjacent land use, however within NW aspect, slopes adjacent to urban areas showed higher values than slopes adjacent secondary forest. Canopy trees species in slopes adjacent to secondary forest were more diverse and rich in SE than in NW, although no differences between aspects were detected within URB-adjacent slopes. Understory species composition was different among the four land use-aspect combinations. However, composition of canopy trees species was different only between aspect types. Most exotic species in the sites were associated with previous agricultural practices and not with current land use. Our results show a temporal and spatial influence of anthropogenic systems on the plant community in karstic forest remnants at a suburban area of Puerto Rico.     

Robust Methods of Building Regression Models—An Application to thè Housing Sector

This article studies robustification strategies for the linear model in the presence of outliers. The advantages of an internal analysis of the robustness of least squares for a given sample are pointed out. The application of this methodology is illustrated by building an explicit model of the determinants of rental housing values in the Madrid Metropolitan Area.     

Is there still such a thing as the ‘European social model'?

This article presents a definition and characterisation of the ‘European social model’ (ESM), admitting the existence of variants and increasing heterogeneity in institutional and social contexts within the EU in the wake of successive enlargements. The constituent parts of the ESM are compared with data observed in the different countries, in search of empirical evidence of the ESM‘s position as a distinctive model of development, characteristic of Western Europe as opposed to the paths taken by other non‐European developed OECD countries.     

Does Parental Participation in Schools Empower or Strain Civil Society? The Case of Community‐managed Schools in Central America

Among the various educational models in Latin America that seek to increase parental participation in schooling, perhaps the most far‐reaching is the experiment with self‐managed schools. These are publicly funded schools administered by parents. Broad public powers, such as the capacity to decide the budget and make staffing decisions, are given to parents, many of whom have had very limited prior administrative experience. How does this policy innovation impact on civil society? Does parental participation in school administration empower participating citizens or strain civil society? There are various ways of answering these questions. This article looks at some possible ways to conceptualize and assess the relationship between parental participation in self‐managed schools and civil society. The article draws from the experience of El Salvador, Guatemala, Honduras and Nicaragua, where these reforms have advanced significantly since the 1990s.