A network-based analysis of the impact of structural damage on urban accessibility following a disaster: the case of the seismically damaged Port Au Prince and Carrefour urban road networks

The magnitude 7.0 earthquake that struck Haiti in January 2010 led to an unprecedented effort in collecting and providing geographical information in support of humanitarian aid. Although most of the compiled datasets and generated maps were able to provide specific and detailed information regarding the location of damaged buildings and road interruptions, none or little information was available to describe the accessibility—or otherwise—of the urban space. Here we try to offer an alternative method to define the urban accessibility landscape in the aftermath of earthquake damage, by combining simple graph theory concepts and GIS-based spatial analysis to assess how the urban space accessibility decreases when the road network is damaged.     

Harmonizing public sector accounting in Europe: thinking out of the box

A broad debate about the harmonization of public sector accounting standards in Europe is underway. The authors provide arguments in favour of harmonization, but they also acknowledge the existing pluralism and diversity by taking stock of the state of play in 14 European countries. The paper makes a proposal for a way forward for policy-makers and standard-setters, in which the benefits of harmonization can be obtained without obliging EU member countries to necessarily abandon their current public sector accounting systems.     

The empirical relevance of the competitive storage model

The empirical relevance of models of competitive storage arbitrage in explaining commodity price behavior has been seriously challenged in a series of pathbreaking papers by [Deaton and Laroque, 1992], [Deaton and Laroque, 1995] and [Deaton and Laroque, 1996]. Here we address their major criticism, that the model is in general unable to explain the degree of serial correlation observed in the prices of twelve major commodities. First, we present a simple numerical version of their model which, contrary to Deaton and Laroque (1992), can generate the high levels of serial correlation observed in commodity prices, if it is parameterized to generate realistic levels of price variation. Then, after estimating the [Deaton and Laroque, 1995] and [Deaton and Laroque, 1996] model using their data set, model specification and econometric approach, we show that the use of a much finer grid to approximate the equilibrium price function yields quite different estimates for most commodities. Results are obtained for coffee, copper, jute, maize, palm oil, sugar and tin that support the specifications of the storage model with positive constant marginal storage cost and no deterioration as in Gustafson (1958a). Consumption demand has a low response to price and, except for sugar, stockouts are infrequent. The observed magnitudes of serial correlation of price match those implied by the estimated model.     

The innovation process as a complex structure with multilevel rules

Increasingly, innovation is conceived in a context of conventions or rules and complexity. However, there is a need for a theoretical basis that describes the innovation process based on complexity. In this essay, we propose a multilevel micro-meso-macro framework that aims to meet this need and further the discussion on complexity. In this framework, the rule is adopted as an analytical concept and used to establish a bridge between the several theories employed. Two gaps are identified in the innovation process: the first is related to the simplicity with which complexity is generally treated, and the second refers to a lack of focus on the rules embedded in the theories used in innovation. The goal of this theoretical essay is to propose a multilevel micro-meso-macro framework, based on the rules and principles of complexity, which can be used to analyze the innovation process. As a result, we propose a new framework in which the innovation rules and the interactions between those rules are detailed and based on principles of complexity.     

Convolution and composition of totally positive random variables in economics

This paper studies a class of multidimensional screening models where different type dimensions can be aggregated into a single-dimensional sufficient statistic. The paper applies results of totally positive functions to show that some critical properties of distributions of asymmetric information parameters, such as increasing hazard rate, monotone likelihood ratio, and single-peakedness are preserved under convolution or composition. Under some general conditions, these invariance results also provide a natural ordering of alternative screening mechanisms. I illustrate how these preservation results provide a unifying framework to interpret several contributions in economic models of adverse selection, moral hazard, and voting.     

Phasing Out Market Mechanisms in the Italian National Health Service

The Italian National Health Service introduced quad-markets, regionalization, and managerialism in the 1990s. Under quasi-markets, large providers have been separated from purchasers and funded by 'activity'—the quantity, mix, and possibly appropriateness of services provided. Under regionalization, each of Italy's 21 regional governments is able to design its own funding arrangements. The regions have generally been trying to mitigate the effects of quasi-markets and are now increasingly 'governing' them. The system is producing some desirable results, including a shift from ordinary to same-day hospitalizations and a reduction in length of stay. Hospital admissions increased initially, but only where the regions encouraged this. Financial effects are more controversial.     

Sul ruolo dei riassunti esaustivi ai fini della previsione in contesto bayesiano (1a parte)

Si studia una nozione di riassunto esaustivo, che diremo a fini predittivi e che è già stata oggetto d'indagine da parte di F. Spizzichino sotto diversa denominazione. Si pone in evidenza la naturalezza di questa nuova definizione che, senza alcuna restrizione, può essere applicata in ogni tipo di ragionamento induttivo. Nella prima parte della ricerca, dopo alcune esemplificazioni sull'applicazione in alcuni tipici problemi inferenziali con particolare riguardo alla costruzione di modelli ipotetici a partire da considerazioni squisitamente predittive del concentto di riassunto esaustivo a fini predittivi, se ne studiano le principali proprietà. Nella seconda parte (che apparirà in un prossimo numero di questa Rivista) se ne analizzeranno i rapporti con le più abituali nozioni di riassunto esaustivo.

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In this paper (first part of a wider work; the second part will appear in the next issue of this journal) we support the idea that the major objective of inductive reasoning is the distribution for outcomes of any sample not jet observed (predictive distribution) Parameters are a secondary device that can ultimately be justified and can lend some simplification.According to this point of view, we study a notion of prediction sufficiency introduced by F. Spizzichino (1978). Many of the results true for classical sufficient statistics apply to our predictive sufficient statistics as we demonstrate in Section 3.In the second part we analyse sequences of predictive sufficient statistics and their relations with classical sufficient statistics for the parameters which are limits of these sequences. The examples of Section 2 represent a first limited approach to this problem.

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Lavoro eseguito nell'ambito del GNAFA-CNR.