Search and bargaining in large markets with homogeneous traders

We study pair-wise decentralized trade in dynamic markets with homogeneous, non-atomic, buyers and sellers that wish to exchange one unit. Pairs of traders are randomly matched and bargaining a price under rules that offer the freedom to quit the match at any time. Market equilbria, prices and trades over time, are characterized. The asymptotic behavior of prices and trades as frictions (search costs and impatience) vanish, and the conditions for (non) convergence to walrasian prices are explored. As a side product of independent interest, we present a self-contained theory of non-cooperative bargaining with two-sided, time-varying, outside options.

Sources of Competitiveness in Tourist Local Systems

At the end of the XIX Century, Marshall described the existence of some concentrations of small and medium enterprises specialised in a specific production activity in certain districts of some industrial English cities. Starting from his contribute, Italian scholars have paid particular attention to this local system of production coined by Marshall under the term industrial district. In other countries, different but related territorial models have played a central role as the milieu or the geographical industrial clusters. Recently, these models have been extended to non-industrial fields like culture, rural activities and tourism. In this text, we explore the extension of these territorial models to the study of tourist activities in Italy, using a framework that can be easily applied to other countries or regions. The paper is divided in five sections. In the first one, we propose a review of the territorial models applied to tourism industry. In the second part, we construct a tourist filiere and we apply a methodology for the identification of local systems through GIS tools. Thus, taxonomy of the Italian Tourist Local Systems is presented. In the third part, we discuss about the sources of competitiveness of these Tourist Local Systems. In the forth section, we test a spatial econometrics model regarding different kinds of Italian Tourist Local Systems (rural systems, arts cities, tourist districts) in order to measure external economies and territorial networks. Finally, conclusions and policy implications are exposed.

Industrial location at a local level: some comments about the territorial level of the analysis

This paper contributes to the existing literature on industrial location by discussing some issues regarding the territorial levels that have been used in location analysis. We analyse which could be the advantages and disadvantages of performing locational analysis at a different local levels. We use data for new manufacturing firms located at municipality, county and travel to work areas level. We show that location determinants vary according to the territorial level used in the analysis, so we conclude that the level at which we perform the investigation should be carefully selected. Keywords: industrial location, cities, agglomeration economies, count data models.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease. 1 - Comparative xenodiagnosis with nine triatomine species of animals with acute infections by Trypanosoma cruzi

In search of a suitable vector species for xenodiagnosis of humans and animals with chronic Chagas' disease we first investigated the reactions of different vector species to acute infection with Trypanosoma cruzi. Vector species utilized in this study were: Triatoma infestans, Rhodnius prolixus and Triatoma dimidiata, all well adapted to human habitats; Triatoma rubrovaria and Rhodnius neglectus both considered totally wild species; Panstrongylus megistus, Triatoma sordida, Triatoma pseudomaculata and Triatoma brasiliensis, all essentially sylvatic but some with domiciliary tendencies and others restricted to peridomestic biotopes with incipient colonization of human houses after successful eradication of T. infestans. Results summarized in Table IV suggest the following order of infectivity among the 9 studied vector species: P. megistus with 97.8% of infected bugs, T. rubrovaria with 95% of positive bugs a close second followed by T. Pseudomaculata with 94.3% and R. neglectus with 93.8% of infected bugs, almost identical thirds. R. prolixus, T. infestans and T. dimidiata exhibited low infection rates of 53.1%, 51.6% and 38.2% respectively, coupled with sharp decreases occuring with aging of infection (Fig. 1). The situation was intermediate in T. brasiliensis and T. sordida infection rates being 76.9% and 80% respectively. Results also point to the existence of a close correlation between prevalence and intensity of infection in that, species with high infection rates ranging from 93.8% to 97.8% exhibited relatively large proportions of insects (27.3% - 33.5%) harbouring very dense populations of T. cruzi. In species with low infection rates ranging from 38.2% to 53.1% the proportion of bugs demonstrating comparable parasite densities was at most 6%. No differences attributable to blood-meal size or to greater susceptibility of indigenous vector species to parasites of their own geographical area, as suggested in earlier...

Clean Development Mechanism and Sustainable Development: a discussion on the link between the CDM and Sustainable Development, an analysis of the current status of the CDM portfolio, and an multicriteria evaluation of the effects of additional incentives in order to foster broad local Sustainable Development dividends from the CDM projects

vegeu resum en el fitxer adjunt a l'inici del treball de recerca

Que faire du couple local/global ? Pour une anthropologie pleinement processuelle

This article examines the uses of the local/global dichotomy in anthropology. It is argued that the use of these terms as analytical tools tends to lead to a reification of "global forces" seen as external to the local site where the ethnographic study takes place. To avoid endless debates on whether or not the "global" can be the object of ethnographic scrutiny, anthropologists should treat the local and the global as scalar properties of social systems that are generated in the course of historical processes.

The dynamics of interfaces: Seven authors in search of encounters across levels of description of an event involving a mother, father, and baby

The interfaces between the intrapsychic, interactional, and intergenerational domains are a new frontier. As a pilot, we exposed ourselves to a complex but controllable situation as viewed by people whose main interest is in one of the three interfaces; we also fully integrated the subjects in the team, to learn about their subjective perspectives and to provide them with an enriching experience. We started with a brief "triadification" sequence (i.e., moving from a "two plus one" to a "three together" family organization). Considering this sequence as representing at a micro level many larger family transitions, we proceeded with a microanalytic interview, a psychodynamic investigation, and a family interview. As expected, larger patterns of correspondences are emerging. Central questions under debate are: What are the most appropriate units at each level of description and what are their articulations between these levels? What is the status of "triadification"? Les interfaces entre les domaines intrapsychiques, interactionnels et intergénérationnels représentent une nouvelle frontiére. A titre exploratoire, nous nous sommes exposés à une situation complexe mais contrǒlable ainsi que le voient ceux dont I'intérět principal se porte sur l'une de ces trois interfaces. Nous avons aussi entièrement intégré les sujets dans l'équipe, de facon à comprendre leur perspective subjective et à leur offrir une expérience enrichissante. Nous avons commencé avec une brève séquence de "triadification," c'est-à-dire passer d'une organisation familiale "deux plus un" à Ltne organisation familiale "trois (add sentenc)ensemble." Considérant cette séquence comme representative à un niveau microscopique de transitions familiales bien plus larges, nous avons procedé à l'entretien microanalytique, à une enquěte psychodynamique et à un entretien familial. Comme prévu, de grands patterns de correspondances émergent. Les questions essentielles sur lesquelles portent le débat sont: quelles les unités les plus appropiées à chaque niveau de description et quelles sont les articulations entre ces niveaux? Quel est le statut de la "triadification"?

Do creative industries cluster? mapping creative local production systems in Italy

An important debate on the role of creativity and culture as factors of local economic development is distinctly emerging. Despite the emphasis put on the theoretical definition of these concepts, it is necessary to strengthen comparative research for the identification and analysis of the kind of creativity embedded in the territory as well as its determinants. Creative local production systems are identified in Italy and Spain departing from local labour markets as territorial units, and focusing on two different kinds of creative

In Search of a theory of debt management

A growing literature integrates theories of debt management into models of optimal fiscal policy. One promising theory argues that the composition of government debt should be chosen so that fluctuations in the market value of debt offset changes in expected future deficits. This complete market approach to debt management is valid even when the government only issues non-contingent bonds. A number of authors conclude from this approach that governments should issue long term debt and invest in short term assets. We argue that the conclusions of this approach are too fragile to serve as a basis for policy recommendations. This is because bonds at different maturities have highly correlated returns, causing the determination of the optimal portfolio to be ill-conditioned. To make this point concrete we examine the implications of this approach to debt management in various models, both analytically and using numerical methods calibrated to the US economy. We find the complete market approach recommends asset positions which are huge multiples of GDP. Introducing persistent shocks or capital accumulation only worsens this problem. Increasing the volatility of interest rates through habits partly reduces the size of these simulations we find no presumption that governments should issue long term debt ? policy recommendations can be easily reversed through small perturbations in the specification of shocks or small variations in the maturity of bonds issued. We further extend the literature by removing the assumption that governments every period costlessly repurchase all outstanding debt. This exacerbates the size of the required positions, worsens their volatility and in some cases produces instability in debt holdings. We conclude that it is very difficult to insulate fiscal policy from shocks by using the complete markets approach to debt management. Given the limited variability of the yield curve using maturities is a poor way to substitute for state contingent debt. The result is the positions recommended by this approach conflict with a number of features that we believe are important in making bond markets incomplete e.g allowing for transaction costs, liquidity effects, etc.. Until these features are all fully incorporated we remain in search of a theory of debt management capable of providing robust policy insights.

Studies in search of a suitable experimental insect model for xenodiagnosis of hosts with Chagas' disease: 2 - Attempts to upgrade the reliability and the efficacy of xenodiagnosis in chronic Chagas' disease

In order to upgrade the reliability of xenodiagnosis, attention has been directed towards population dynamics of the parasite, with particular interest for the following factors: 1. Parasite density which by itself is not a research objective, but by giving an accurate portrayal of parasite development and multiplication, has been incorporated in screening of bugs for xenodiagnosis. 2. On the assumption that food availability might increase parasite density, bugs from xenodiagnosis have been refed at biweekly intervals on chicken blood. 3. Infectivity rates and positives harbouring large parasite yields were based on gut infections, in which the parasite population comprised of all developmental forms was more abundant and easier to detect than in fecal infections, thus minimizing the probability of recording false negatives. 4. Since parasite density, low in the first 15 days of infection, increases rapidly in the following 30 days, the interval of 45 days has been adopted for routine examination of bugs from xenodiagnosis. By following the enumerated measures, all aiming to reduce false negative cases, we are getting closer to a reliable xenodiagnostic procedure. Upgrading the efficacy of xenodiagnosis is also dependent on the xenodiagnostic agent. Of 9 investigated vector species, Panstrongylus megistus deserves top priority as a xenodiagnostic agent. Its extraordinary capability to support fast development and vigorous multiplication of the few parasites, ingested from the host with chronic Chagas' disease, has been revealed by the strikingly close infectivity rates of 91.2% vs. 96.4% among bugs engorged from the same host in the chronic and acute phase of the disease respectively (Table V), the latter comporting an estimated number of 12.3 x 10[raised to the power of 3] parasites in the circulation at the time of xenodiagnosis, as reported previously by the authors (1982).

Economic impact of a new museum on the local economy: "The Gaudí Centre"

In this paper we analyse the economic impact of a new museum (the Gaudí Centre) on the local economy of Reus, a city in the province of Tarragona (southern Catalonia). We use a Keynesian income multiplier model to evaluate the effects of this new cultural venue on local income. In our calculation of the economic impact we distinguish between two phases: the construction phase and the exploitation phase. Our results show the important income impact of this cultural investment on the local economy.

Schistosomiasis mansoni: immunodiagnosis aspects and search for an immunological marker related to therapeutic efficacy

The recent findings on immunodiagnosis of schistosomiasis mansoni have shown that purified Schistosoma mansoni antigens do not provide maximum positivity. Therefore, the authors suggest the use of semi-purified antigens for diagnostic purposes. So far, no serological marker for cured patients as shown by negative stool examination was found. However, a tendency of IgG antibody titre decrease was observed, when egg antigen was used.