0000000000003202
AUTHOR
Mauro Gallegati
Backbone of credit relationships in the Japanese credit market
We detect the backbone of the weighted bipartite network of the Japanese credit market relationships. The backbone is detected by adapting a general method used in the investigation of weighted networks. With this approach we detect a backbone that is statistically validated against a null hypothesis of uniform diversification of loans for banks and firms. Our investigation is done year by year and it covers more than thirty years during the period from 1980 to 2011. We relate some of our findings with economic events that have characterized the Japanese credit market during the last years. The study of the time evolution of the backbone allows us to detect changes occurred in network size,…
Bank-firm credit network in Japan. An analysis of a bipartite network
We present an analysis of the credit market of Japan. The analysis is performed by investigating the bipartite network of banks and firms which is obtained by setting a link between a bank and a firm when a credit relationship is present in a given time window. In our investigation we focus on a community detection algorithm which is identifying communities composed by both banks and firms. We show that the clusters obtained by directly working on the bipartite network carry information about the networked nature of the Japanese credit market. Our analysis is performed for each calendar year during the time period from 1980 to 2011. Specifically, we obtain communities of banks and networks …
Do firms share the same functional form of their growth rate distribution? A statistical test
We introduce a new statistical test of the hypothesis that a balanced panel of firms have the same growth rate distribution or, more generally, that they share the same functional form of growth rate distribution. We applied the test to European Union and US publicly quoted manufacturing firms data, considering functional forms belonging to the Subbotin family of distributions. While our hypotheses are rejected for the vast majority of sets at the sector level, we cannot rejected them at the subsector level, indicating that homogenous panels of firms could be described by a common functional form of growth rate distribution.
The Dynamic of Innovation Networks: A Switching Model on Technological Change
In this paper we introduce an agent-based model with heterogeneous firms which compare their mutual innovation strategies on different network structures. By implementing a dynamic behavioral switching via a fitness mechanism based on agents performance, companies can endogenously modify their tactics of technological change and switch among three groups: stand-alone innovators, collaborative innovators and imitators. We focus the analysis on the impact of these three innovation categories on micro, meso and macro aggregates. Our findings show that collaborative companies are those having the highest positive impact on the economic system. Moreover, we study the properties of the emerging n…
Special issue of Quantitative Finance on ‘Interlinkages and Systemic Risk’
This special issue of Quantitative Finance collects eight papers on the relation between interlinkages and systemic risk. The papers cover several types of interlinkages and follow different approaches, from agent-based modelling to empirical investigation of large and sometimes confidential data. The special issue collects some of the contributions presented at the international workshop‘Interlinkages and systemic risk ’ , which took place in Ancona (Italy) on 4 – 5 July 2013. The workshop, organized within the research project‘. New tools in the credit network modeling with agents ’ heterogeneity ’ funded by the Institute for New Economic Thinking, was attended by a balanced mix of schola…
Financial Fragility and Distress Propagation in a Network of Regions
Building on previous works on business fluctuations, we model the propagation of financial distress in a network of regions, each populated by heterogeneous interacting firms and banks. In order to diversify risk, firm sell goods outside their own region and borrow from banks located there. However, this results in ties across regions which propagate financial distress across regional borders. We investigate how the average level of economic integration affects the probability of both individual and systemic failures. We find that the benefit of greater diversification is eventually offset by the effect of financial acceleration and contagion. In particular, beyond a certain level of integr…
Cluster analysis for portfolio optimization
We consider the problem of the statistical uncertainty of the correlation matrix in the optimization of a financial portfolio. We show that the use of clustering algorithms can improve the reliability of the portfolio in terms of the ratio between predicted and realized risk. Bootstrap analysis indicates that this improvement is obtained in a wide range of the parameters N (number of assets) and T (investment horizon). The predicted and realized risk level and the relative portfolio composition of the selected portfolio for a given value of the portfolio return are also investigated for each considered filtering method.
Do Firms Share the Same Functional Form of Their Growth Rate Distribution? A New Statistical Test
We propose a hypothesis testing procedure to investigate whether the same growth rate distribution is shared by all the firms in a balanced panel or, more generally, whether they share the same functional form for this distribution, without necessarily sharing the same parameters. We apply the test to panels of US and European Union publicly quoted manufacturing firms, both at the sectoral and at the subsectoral NAICS levels. We consider the following null hypotheses about the growth rate distribution of the individual firms: i) an unknown shape common to all firms, with all the firms sharing also the same parameters, or with the firm variance related to its firm size through a scaling rela…