A note on the optimal level of public inputs

This paper analyses whether the first-best level of public inputs exceeds the second-best level. On the basis of a simple model, we argue that the level of productivity-enhancing public expenditures is always higher than the level of public inputs provided with distortionary taxation.     

Volunteer Motivation and Organizational Climate: Factors that Promote Satisfaction and Sustained Volunteerism in NPOs

Keeping volunteers committed and engaged is one of the toughest challenges for NPOs. The aim of the present study is to investigate the individual and organizational factors that promote volunteer satisfaction and, vice versa, foster intentions to quit. Two hundred forty-seven volunteers operating in four different NPOs were asked to fill in a self-report questionnaire that aimed to explore their motivations to volunteer, their degree of satisfaction and their perception of the organizational climate in the NPO they worked with, in addition to providing details of the activities which they were involved in. Results showed that the organizational climate mediates the relationship between autonomous motivation and satisfaction, as well as that between external motivation and intentions to leave an organization.     

Are invasive House Sparrows a nuisance for native avifauna when scarce?

Biological invasions are the second most important cause of species extinction. Aided by processes such as transportation and urbanization, exotic species can establish and spread to new locations, causing changes in the function and structure of ecosystems. The House Sparrow is a widespread and highly abundant landbird associated to human presence. Previous studies performed in urban landscapes have suggested that this species could be acting, in synergy with urbanization, as a potential threat to native urban avian assemblages. In this study we assessed the relationship between House Sparrow density and native bird species richness in a region where the sparrows are scarce and sparsely distributed. We surveyed bird assemblages in and around four small-sized human settlements, considering three conditions in relation to House Sparrow presence: urban invaded, urban non-invaded, and non-urban non-invaded. To assess the potential detrimental role of House Sparrows on native bird species richness, we measured, additionally to sparrow densities, 20 predictor variables that describe vegetation structure and complexity, as well as urban infrastructure and human activities across four seasons of 1 year. Our results show that maximum shrub height was positively related to bird species richness, built cover was negatively associated with it, and House Sparrow invaded sites were related to a significant decrease of bird species richness, with increasing richness loss when more sparrows were present. Thus, we here provide evidence that urban areas can act in synergy with the presence of House Sparrows (even in low densities) in the urban-related species richness decline pattern.

     

Sustainable Conservation of Cultural Heritage: A Global Responsibility. Sichuan Towers Case Study

This paper has been developed in the framework of a larger research program, in which the University of Rome “Tor Vergata”, Tsinghua University and Yangzhou University are jointly involved to study and preserve historic towers. Cultural heritage is the intangible and tangible attributes of a society, including the natural heritage, that are inherited from past generations, preserved in the present and granted for the next generations. Nowadays we consider the cultural heritage as a world heritage belonging to all the people of the world, irrespective on which territory they are located. This paper presents a model and a methodological hypothesis to conserve cultural heritage in a sustainable way throughout the case study of Sichuan Towers (China) that could become an example for other cultural sites around the world, connecting the environmental and socio-economical aspect to the tourism development.      

Economic consequences of Nth-degree risk increases and Nth-degree risk attitudes

We study comparative statics of Nth-degree risk increases within a large class of problems that involve bidimensional payoffs and additive or multiplicative risks. We establish necessary and sufficient conditions for unambiguous impact of Nth-degree risk increases on optimal decision making. We develop a simple and intuitive approach to interpret these conditions : novel notions of directional Nth-degree risk aversion that are characterized via preferences over lotteries.     

Parameter changes in a regression model with autocorrelated errors

This study is a Bayesian analysis of a regression model with autocorrelated errors which exhibits one change in the regression parameters and where the autocorrelation parameter is unknown

Using a normal-gamma prior for all the parameters except the shift point which has a uniform distribution, the marginal posterior distribution of the regression parameters, the shift point and the precision of the errors is found. It is important to know where the shift occurred thus the main emphasis is with the posterior distribution of the shift point

A numerical study assesses the effect of the values of the shift point and the magnitude of the shift on the posterior distribution of the shift point. The posterior distribution of the shift point is more sensitive to change, which occurs in the middle of the observations than to one which occurs at an extreme of the data.     

Structural changes in multivariate regression models

This study generalizes the work of chin choy and Broemeling (1980) who investigated the change in the regression parameters of univariate linear models.

The marginal posterior distributions of the change point, the regression matrices,and the precision matrix are found with the use of a proper multivariate normal-Wishart distribution for the parameters of the model.

A numerical study is undertaken in order to gain some insight into the effect that changes in sample size and certain parameter values have on these marginal posterior distributions.     

Turning the Immigration Policy Paradox Upside Down? Populist Liberalism and Discursive Gaps in South America

A paradox of officially rejecting but covertly accepting irregular migrants has long been identified in the immigration policies of Western immigrant receiving states. In South America, on the other hand, a liberal discourse of universally welcoming all immigrants, irrespective of their origin and migratory status, has replaced the formally restrictive, securitized and not seldomly ethnically selective immigration rhetoric. This discursive liberalization has found partial translation into immigration laws and policies, but contrary to the universality of rights claimed in their discourses, governments reject recently increasing irregular south–south migration from Africa, Asia, and the Caribbean to varying degrees. This paper applies a mixed methodological approach of discourse and legal analysis and process tracing to explore in how far recent immigration policies in South America constitute a liberal turn, or rather a reverse immigration policy paradox of officially welcoming but covertly rejecting irregular migrants. Based on the comparative analysis of Argentina, Brazil and Ecuador, the study identifies and explains South American “populist liberalism” in the sphere of migration. We highlight important implications for migration theory, thereby opening up new avenues of research on immigration policy making outside Western liberal democracies, and particularly in predominantly migrant sending countries.