Country Diversification, Product Ubiquity, and Economic Divergence

Countries differ markedly in the diversification of their exports. Products differ in the number of countries that export them, which we define as their ubiquity. We document a new stylized fact in the global pattern of exports: there is a systematic relationship between the diversification of a country’s exports and the ubiquity of its products. We argue that this fact is not implied by current theories of international trade and show that it is not a trivial consequence of the heterogeneity in the level of diversification of countries or of the heterogeneity in the ubiquity of products. We account for this stylized fact by constructing a simple model that assumes that each product requires a potentially large number of non-tradable inputs, which we call capabilities, and that a country can only make the products for which it has all the requisite capabilities. Products differ in the number and specific nature of the capabilities they require, as countries differ in the number/nature of capabilities they have. Products that require more capabilities will be accessible to fewer countries (i.e., will be less ubiquitous), while countries that have more capabilities will have what is required to make more products (i.e., will be more diversified). Our model implies that the return to the accumulation of new capabilities increases exponentially with the number of capabilities already available in a country. Moreover, we find that the convexity of the increase in diversification associated with the accumulation of a new capability increases when either the total number of capabilities that exist in the world increases or the average complexity of products, defined as the number of capabilities products require, increases. This convexity defines what we term as a quiescence trap, or a trap of economic stasis: countries with few capabilities will have negligible or no return to the accumulation of more capabilities, while at the same time countries with many capabilities will experience large returns - in terms of increased diversification - to the accumulation of additional capabilities. We calibrate the model to three different sets of empirical data and show that the derived functional forms reproduce the empirically observed distributions of product ubiquity, the relationship between the diversification of countries and the average ubiquity of the products they export, and the distribution of the probability that two products are co-exported. This calibration suggests that the global economy is composed of a relatively large number of capabilities – between 23 and 80, depending on the level of disaggregation of the data – and that products require on average a relatively large fraction of these capabilities in order to be produced. The conclusion of this calibration is that the world exists in a regime where the quiescence trap is strong

The Network Structure of Economic Output

Much of the analysis of economic growth has focused on the study of aggregate output. Here, we deviate from this tradition and look instead at the structure of output embodied in the network connecting countries to the products that they export. We characterize this network using four structural features: the negative relationship between the diversification of a country and the average ubiquity of its exports, and the non-normal distributions for product ubiquity, country diversification and product co-export. We model the structure of the network by assuming that products require a large number of non-tradable inputs, or capabilities, and that countries differ in the completeness of the set of capabilities they have. We solve the model assuming that the probability that a country has a capability and that a product requires a capability are constant and calibrate it to the data to find that it accounts well for all of the network features except for the heterogeneity in the distribution of country diversification. In the light of the model, this is evidence of a large heterogeneity in the distribution of capabilities across countries. Finally, we show that the model implies that the increase in diversification that is expected from the accumulation of a small number of capabilities is small for countries that have a few of them and large for those with many. This implies that the forces that help drive divergence in product diversity increase with the complexity of the global economy when capabilities travel poorly

The Structure and Dynamics of International Development Assistance

We study the structure of international aid coordination by creating and analyzing a tripartite network of donor organizations, recipient countries and development issues using web-based information. We develop a measure of coordination and find that it is moderate, achieving about 60% of its theoretical maximum. Many countries are strongly connected to organizations that are related to the issues that are salient there. Nevertheless, we identify many countries that are poorly served, issues that are inadequately attended to, and organizations that focus on the wrong combination of places and issues. Our approach may be used to improve decentralized coordination

International Knowledge Diffusion and the Comparative Advantage of Nations

In this paper we document that the probability that a product is added to a country’s export basket is, on average, 65% larger if a neighboring country is a successful exporter of that same product. We interpret our result as evidence of international intra-industry knowledge diffusion. Our results are consistent with the overall consensus in the literature on technology spillovers: diffusion is stronger at shorter distances; is weaker for more knowledge-intensive products; and has become faster over time

Paleosalinidad y tamaño de las valvas del ostrácodo Cyprideis torosa (Jones) en niveles del Pleistoceno inferior y medio.

The correlation between the size of Lower and Middle Pleistocene Cyprideis torosa Oones) ostracode valves and paleosalinity reveal the existence ofa direct relationship though little significant. This observation suggest that in spite of the two areas of Cullar-Baza Basin, where the ostracodes have been picked, were controlled under similar general paleoclimatic conditions, the particular and local paleogeographical conditions had a major influence not only in the specific diversity but also in the morphology of the ostracodes

Spatial dependence of the Star Formation History in the Central Regions of the Fornax Dwarf Spheroidal Galaxy

We present the Star Formation History (SFH) and the age-metallicity relation (AMR) in three fields of the Fornax dwarf spheroidal galaxy. They sample a region spanning from the centre of the galaxy to beyond one core radius, which allows studying galactocentric gradients. In all the cases, we found stars as old as 12 Gyr, together with intermediate-age and young stellar populations. The last star formation events, as young as 1 Gyr old, are mainly located in the central region, which may indicate that the gas reservoir in the outer parts of the galaxy would have been exhausted earlier than in the centre or removed by tidal interactions. The AMR is smoothly increasing in the three analyzed regions and similar to each other, indicating that no significant metallicity gradient is apparent within and around the core radius of Fornax. No significant traces of global UV-reionization or local SNe feedback are appreciated in the early SFH of Fornax. Our study is based on FORS1@VLT photometry as deep as I~24.5 and the IAC-star/IAC-pop/MinnIAC suite of codes for the determination of the SFH in resolved stellar populations.Comment: 13 pages, 8 figures, 4 table