The paper develops a model of proportionate growth to describe the dynamics of international trade flows. We show that a large number of the empirical regularities characterizing international trade — such as the fraction of zero trade flows across pairs of countries, the positive relationship...

Considerable efforts have been made in recent years to produce detailed topologies of the Internet, but so far these data have been overlooked by economists. In this paper, we suggest that such information could be used to characterize both the size of the digital economy and outsourcing at...

This paper contributes to the literature explaining firm-level heterogenenity in the extensive margin of trade, defined as the number of products exported by each firm. We develop a dynamic model where firms must invest in RD to maintain and increase their portfolio of goods: the process of...

The proper characterization of the size distribution of business firms represents an important issue in economic literature, with the most common reference distribu- tions being the lognormal and the Pareto varieties. This analysis is related to some methodological issues that are rarely...

This paper presents a simple stochastic model of proportionate growth to describe international trade and it applies this set-up to the relationship between export dynamics and economic development. Trade flows are assumed to grow as a geometric Brownian motion while new trade links follow a...

We develop a simple theoretical framework for the evolution of weighted networks that is consistent with a number of stylized features of real-world data. In our framework, the Barabasi-Albert model of network evolution is extended by assuming that link weights evolve according to a geometric...

Considerable efforts have been made in the recent years to produce detailed topolo- gies of the Internet. While Internet topology data have brought to the attention of a wide and somehow diverse audience of scholars they have been so far over- looked by economic analyses. In this paper we...

Several economic phenomena are found to follow an approximate Pareto distribution, at least in the upper tail. The debate is well established for the distribution of wealth and business firms, and has recently been particularly animated with respect to city sizes. In this paper we contribute to...

This paper develops a simple network model to describe the dynamic of the intensive and extensive margin of international trade flows. The result is achieved by means of the combination of two mechanisms of proportional growth: the first (discrete) determines the formation of trade links, the...

In this paper we develop a network model of international trade which is able to replicate the concentrated and sparse nature of trade data. Our model extends the preferential attachment (PA) growth model to the case of multiple networks. Countries trade a variety of goods of different...