Community structure in the World Trade Network based on communicability distances

In this paper, we investigate the mesoscale structure of the World Trade Network. In this framework, a specific role is assumed by short- and long-range interactions, and hence by any suitably defined network-based distance between countries. Therefore, we identify clusters through a new procedure that exploits Estrada communicability distance and the vibrational communicability distance, which turn out to be particularly suitable for catching the inner structure of the economic network. The proposed methodology aims at finding the distance threshold that maximizes a specific quality function defined for general metric spaces. Main advantages regard the computational efficiency of the procedure as well as the possibility to inspect intercluster and intracluster properties of the resulting communities. The numerical analysis highlights peculiar relationships between countries and provides a rich set of information that can hardly be achieved within alternative clustering approaches.

     

A spatial theory of urban segregation

We provide a competitive equilibrium theory of urban segregation in a linear city. Households demand consumption and housing along the city and are exposed to neighborhood externalities. We show that equilibria that are robust to small coalitional deviations are segregated. Our results explain urban segregation in a standard neoclassical framework and shed new light on the difficulties faced by authorities to integrate cities.     

Teaching an old dog a new trick: Reserve price and unverifiable quality in repeated procurement

This paper shows that, in a repeated competitive procurement, a buyer can use the reserve price in a low-price auction as a “public”—hence nondiscriminatory—incentive device to elicit unverifiable quality. We study a model with many firms and one buyer, who is imperfectly informed on the firms' costs. When firms are ex ante identical, the provision of quality is sustained by a sufficiently high reserve price to reward firms for the quality provision and by the threat of setting a low reserve price forever, if quality is not delivered. The buyer can elicit the desired level of unverifiable quality provided her baseline valuation of the project is not too high and the net benefit from unverifiable quality is not too low. These results are robust to firms' heterogeneity in their time preferences when the punishment for a deviation is finite but sufficiently long.     

Reading cases of local quality of life assessment as incomplete and socio-politically contentious practices

Quality & Quantity - Quality of life represents one of the most relevant and controversial issues in the contemporary socio-economic and political scene. This paper examines local quality of...