Occupational mobility and wealth evolution in a model of educational investment with credit market imperfections

We study the implications of individual heterogeneity for occupational mobility and the evolution of wealth distribution. These issues are investigated within a model of occupational choice with credit market imperfections and local non convexities in educational investment. Whether and under which conditions private wealth accumulation leads to the elimination of the effects of credit market imperfections is also studied. In the cases where steady states feature wealth and occupational mobility we show that private wealth accumulation cannot eliminate the effects of credit market imperfections if, at any point in time, investment correlates with wealth within households in the skilled occupation. Persistence of wealth constraints in the economy with occupational mobility motivates our exploration of policies. Compared to the case of homogeneous ability, we show that heterogeneity requires more persistent policies to achieve similar results in terms of enhanced investment opportunities and income per capita. It is also shown that the scope for policies is larger under heterogeneity: policies can be effective in environments where they would fail in a world of homogeneous abilities.     

Financial Instruments for Mitigation of Flood Risks: The Case of Florence

This article analyzes the mechanisms and effects of innovative financial instruments that a central public administration (CPA) may adopt to minimize the flood risk in particularly exposed regions. The pattern we suggest assumes that in risky areas the CPA can issue two financial instruments, called project options and CAT‐bonds, producing a dynamic interaction among three types of agents: the CPA itself, the local public administrations, and private investors. We explore the possible scenarios of such interaction and the conditions under which the CPA's goal of maximal risk reduction is attained. This pattern is proposed for flood risk mitigation in the city of Florence, where the model dynamics are tested assuming parameters obtained from engineering studies.     

A sustainable urban regeneration project to protect biodiversity

Urban Ecosystems - The sustainable urban redevelopment project to protect biodiversity was developed to regenerate the external spaces of an ancient rural farmhouse, Villa Framarino, in the...     

Urban fragmentation as a research hypothesis: Rabat-Salé case study

Cities in developing countries display distinct spatial patterns which are increasingly recognised as the fragmentation of urban space. Although the reason for this is largely unknown, it is necessary to recognise it in order to shape appropriate urban policies.This paper is concerned with a study of Rabat-Salé, Morocco, testing the hypothesis that physically different fragments determine distinctive ways of using the city. The peculiar morphological characteristics of eight fragments were identified and, based on information from a sample survey, three issues were investigated: places of reference and the accessibility to infrastructure and services; the household's residential trajectory within the agglomeration; and the family network and its spatial location. It was found that the differences in the use of the city were not systematic among the population of the various fragments. What emerges is more a social integration resulting from a mixing at the level of family, clan or region of origin, than a societal fragmentation. The research confirms that although two distinct and at times divergent urban spaces exist, they do not necessarily conflict. These differences depend principally upon household social and economic conditions. It is essential that urban management and planning take these factors into account.     

Diversity as width

It is argued that if a finite partially ordered population is given, and incomparability is taken as the relevant type of dissimilarity, then diversity comparisons between subpopulations may be conveniently based on widths namely on the maximum number of pairwise incomparable units they include. We introduce two width-based rankings. The first one is the plain width-ranking of subposets as induced by width computation. The second one is the undominated width-ranking of subposets namely the ranking induced by the sizes of undominated subposets. Simple axiomatic characterizations of the foregoing rankings are provided.     

Including covariates in a space-time point process with application to seismicity

The paper proposes a spatio-temporal process that improves the assessment of events in space and time, considering a contagion model (branching process) within a regression-like framework to take covariates into account. The proposed approach develops the forward likelihood for prediction method for estimating the ETAS model, including covariates in the model specification of the epidemic component. A simulation study is carried out for analysing the misspecification model effect under several scenarios. Also an application to the Italian seismic catalogue is reported, together with the reference to the developed R package.

     

Financial contagion through space-time point processes

Statistical Methods & Applications - We propose to study the dynamics of financial contagion by means of a class of point process models employed in the modeling of seismic contagion. The...     

Children in Need in the South of Italy: Features and Distortions in the Deinstitutionalisation of Care

Despite the shift in emphasis from institutional to foster family care, in the south of Italy children in need are mainly looked after by residential services. These are required to provide family‐style care and to place children on a short‐term basis. Using data from research on a 100% sample of day units, residential services and children in care in the Calabria region, this article investigates the functioning of the system of care for vulnerable children at the sub‐national level, describes looked‐after children’s characteristics and life conditions and questions the extent to which a real deinstitutionalisation process has occurred in this area. Finally, some deinstitutionalisation recommendations are given.     

What’s so special about Euclidean distance?

In this paper, we provide an application-oriented characterization of a class of distance functions monotonically related to the Euclidean distance in terms of some general properties of distance functions between real-valued vectors. Our analysis hinges upon two fundamental properties of distance functions that we call “value-sensitivity” and “order-sensitivity”. We show how these two general properties, combined with natural monotonicity considerations, lead to characterization results that single out several versions of Euclidean distance from the wide class of separable distance functions. We then discuss and motivate our results in two different and apparently unrelated application areas—mobility measurement and spatial voting theory—and propose our characterization as a test for deciding whether Euclidean distance (or some suitable variant) should be used in your favourite application context. We would like to thank an editor and especially two anonymous referees for very useful comments which helped us to improve the paper substantially.