Journal Articles

2017
Coscia, M. & Neffke, F., 2017. Network Backboning with Noisy Data. 2017 IEEE 33rd International Conference on Data Engineering (ICDE) , (May) , pp. 425-436. Publisher's VersionAbstract
Networks are powerful instruments to study complex phenomena, but they become hard to analyze in data that contain noise. Network backbones provide a tool to extract the latent structure from noisy networks by pruning non-salient edges. We describe a new approach to extract such backbones. We assume that edge weights are drawn from a binomial distribution, and estimate the error-variance in edge weights using a Bayesian framework. Our approach uses a more realistic null model for the edge weight creation process than prior work. In particular, it simultaneously considers the propensity of nodes to send and receive connections, whereas previous approaches only considered nodes as emitters of edges. We test our model with real world networks of different types (flows, stocks, cooccurrences, directed, undirected) and show that our Noise-Corrected approach returns backbones that outperform other approaches on a number of criteria. Our approach is scalable, able to deal with networks with millions of edges.
Inter-industry Labor Flows
Neffke, F., Otto, A. & Weyh, A., 2017. Inter-industry Labor Flows. Journal of Economic Behavior and Organization , 142 (October) , pp. 275-292. Publisher's VersionAbstract

Using German social security data, we study inter-industry labor mobility to assess how industry-specific human capital is and to determine which industries have similar human capital requirements. We find that inter-industry labor flows are highly concentrated in just a handful of industry pairs. Consequently, labor flows connect industries in a sparse network. We interpret this network as an expression of industries similarities in human capital requirements, or skill relatedness. This skill-relatedness network is stable over time, similar for different types of workers and independent of whether workers switch jobs locally or over larger distances. Moreover, in an application to regional diversification and local industry growth, skill relatedness proves to be more predictive than colocation or value chain relations. To facilitate future research, we make detailed inter-industry relatedness matrices online available.

    inter_industry_labor_jebo.pdf
    What is different about urbanization in rich and poor countries? Cities in Brazil, China, India and the United States
    Chauvin, J.P., et al., 2017. What is different about urbanization in rich and poor countries? Cities in Brazil, China, India and the United States. Journal of Urban Economics , 98 (March 2017) , pp. 17-49. Publisher's VersionAbstract
    Are the well-known facts about urbanization in the United States also true for the developing world? We compare American metropolitan areas with analogous geographic units in Brazil, China and India. Both Gibrat’s Law and Zipf’s Law seem to hold as well in Brazil as in the U.S., but China and India look quite different. In Brazil and China, the implications of the spatial equilibrium hypothesis, the central organizing idea of urban economics, are not rejected. The India data, however, repeatedly rejects tests inspired by the spatial equilibrium assumption. One hypothesis is that spatial equilibrium only emerges with economic development, as markets replace social relationships and as human capital spreads more widely. In all four countries there is strong evidence of agglomeration economies and human capital externalities. The correlation between density and earnings is stronger in both China and India than in the U.S., strongest in China. In India the gap between urban and rural wages is huge, but the correlation between city size and earnings is more modest. The cross-sectional relationship between area-level skills and both earnings and area-level growth are also stronger in the developing world than in the U.S. The forces that drive urban success seem similar in the rich and poor world, even if limited migration and difficult housing markets make it harder for a spatial equilibrium to develop.
    Sanctions and Export Deflection: Evidence from Iran
    Haidar, J.I., 2017. Sanctions and Export Deflection: Evidence from Iran. Economic Policy , 32 (90) , pp. 319–355. Publisher's VersionAbstract
    Do export sanctions cause export deflection? Data on Iranian non-oil exporters between January 2006 and June 2011 shows that two-thirds of these exports were deflected to non-sanctioning countries after sanctions were imposed in 2008, and that at this time aggregate exports actually increased. Exporting firms reduced prices and increased quantities when exporting to a new destination, however, and suffered welfare losses as a result.
    economic_policy_haider_april_2017.pdf
    2016
    Santos, M. & Reinhart, C., 2016. From Financial Repression to External Distress: The Case of Venezuela. Emerging Markets Finance and Trade , (Jan. 2016) , pp. 1-30. Publisher's VersionAbstract
    Recent work suggests a connection between domestic debt and external default. We examine potential linkages for Venezuela, where the evidence reveals a nexus among domestic debt, financial repression, and external vulnerability. The financial repression tax (as a share of GDP) is similar to OECD economies, in spite of higher debt ratios in the latter. The financial repression “tax rate” is higher in years of exchange controls and legislated interest rate ceilings. We document a link between domestic disequilibrium and a weakening of the net foreign asset position via private capital flight. We suggest these findings are not unique to Venezuela.
    from_financial_-emerging_markets_finance_and_.pdf
    Santos, M., 2016. The Right Fit for the Wrong Reasons: Real Business Cycle in an Oil-Dependent Economy. Latin American Journal of Economics (former Cuadernos de Economía) , 53 (1) , pp. 61-94. Publisher's VersionAbstract
    Venezuela has an oil-dependent economy subject to large exogenous shocks and a rigid labor market. These features go straight to the heart of two weaknesses of real business cycle (RBC) theory widely reported in the literature: neither shocks are volatile enough nor real salaries suf ficiently flexible as required by the RBC framework to replicate the behavior of the economy. We calibrate a basic RBC model and compare a set of relevant statistics from RBC-simulated time series with actual data for Venezuela and the benchmark case of the United States (1950–2008). Despite Venezuela being a heavily regulated economy, RBC-simulated series provide a good fit, in particular with regard to labor markets.
    107764_laje_53161.pdf
    O'Clery, N., 2016. A Tale of Two Clusters: The Evolution of Ireland’s Economic Complexity since 1995. Journal of the Statistical and Social Inquiry Society of Ireland , XLV 2015-16 , pp. 16-66. Publisher's VersionAbstract
    This paper characterizes the evolution of the manufacturing and industrial export structure of Ireland since 1995 within the framework of Economic Complexity and the Product Space. We observe a high level of specialisation in Ireland’s export structure, coupled with high income per capita as compared to the complexity level of its industrial activities (as captured by its Economic Complexity Index). We identify a dual structure within the economy, with domestic and foreign-owned exporters exhibiting distinct characteristics. In the latter case, we observe a recent consolidation and reduction in complexity level by the foreign-owned high tech pharmaceuticals and electronics sectors, with limited evidence of spill-overs leading to growth of domestic firms in these sectors. This contrasts with a dynamic and growing domestic food and agriculture sector, which is well positioned for continued expansion of Ireland’s indigenous activities into more complex goods. Finally, we illustrate this framework as a tool for policy-makers by identifying some potential new sectors that share many inputs with Ireland’s current domestic capability base, and could increase Ireland’s complexity level for future growth.
    2_oclery.pdf
    Of Knights and Squires: European Union and the Modernization of Albania
    Frasheri, E., 2016. Of Knights and Squires: European Union and the Modernization of Albania. North Carolina Journal of International Law , 42 (1) , pp. 1.Abstract

    In this paper, I question the idea that a country develops and democratizes merely by pursuing a model of deeper regional integration with more prosperous countries. I examine the case of Albania’s integration into the European Union to show that more often than not, transition reproduces hierarchies and inequities that usually underpin relations between a prosperous center and a backward periphery. Instead of being a cure, a solution to the political primitivism and underdevelopment, the story with Europeanization as a model of modernization suggests that despite noble intentions and goals, reforms in the name of the European Union end up foregrounding a security state apparatus, impose an ideological hegemony, and maintain a political culture that inhibits democratization, while discouraging and displacing the need for endogenous growth strategies.

    Explaining the prevalence, scaling and variance of urban phenomena
    Gomez-Lievano, A., Patterson-Lomba, O. & Hausmann, R., 2016. Explaining the prevalence, scaling and variance of urban phenomena. Nature Human Behavior. Publisher's VersionAbstract

    The prevalence of many urban phenomena changes systematically with population size1 . We propose a theory that unifies models of economic complexity2,3 and cultural evolution4 to derive urban scaling. The theory accounts for the difference in scaling exponents and average prevalence across phenomena, as well as the difference in the variance within phenomena across cities of similar size. The central ideas are that a number of necessary complementary factors must be simultaneously present for a phenomenon to occur, and that the diversity of factors is logarithmically related to population size. The model reveals that phenomena that require more factors will be less prevalent, scale more superlinearly and show larger variance across cities of similar size. The theory applies to data on education, employment, innovation, disease and crime, and it entails the ability to predict the prevalence of a phenomenon across cities, given information about the prevalence in a single city.

    Related Content: The Urban Theory of Everything

    Harvard Magazine: Recipes for Thriving Cities

    Abt, T., 2016. Towards a framework for preventing community violence among youth. Psychology, Health & Medicine , pp. 1-20. Publisher's VersionAbstract

    This article, in an effort to assist the selection and deployment of evidence-informed strategies, proposes a new conceptual framework for responding to community violence among youth. First, the phenomenon of community violence is understood in context using a new violence typology organized along a continuum. Second, the need for a new anti-community violence framework is established. Third, a framework is developed, blending concepts from the fields of public safety and public health. Fourth, evidence from systematic reviews and meta-analyses concerning community violence is summarized and categorized. Finally, an anti-violence framework populated with evidence-informed strategies is presented and discussed.

    2015
    Evidence That Calls-Based and Mobility Networks Are Isomorphic
    Coscia, M. & Hausmann, R., 2015. Evidence That Calls-Based and Mobility Networks Are Isomorphic. PLOS One , 10. Publisher's VersionAbstract

    Social relations involve both face-to-face interaction as well as telecommunications. We can observe the geography of phone calls and of the mobility of cell phones in space. These two phenomena can be described as networks of connections between different points in space. We use a dataset that includes billions of phone calls made in Colombia during a six-month period. We draw the two networks and find that the call-based network resembles a higher order aggregation of the mobility network and that both are isomorphic except for a higher spatial decay coefficient of the mobility network relative to the call-based network: when we discount distance effects on the call connections with the same decay observed for mobility connections, the two networks are virtually indistinguishable.

    Chekir, H. & Diwan, I., 2015. Crony Capitalism in Egypt. Journal of Globalization and Development.Abstract

    The paper studies the nature and extent of Egyptian "crony" capitalism by comparing the corporate performance and the stock market valuation of politically connected and unconnected firms, before and after the 2011 popular uprising that led to the end of President Mubarak 30 years rule. First, we identify politically connected firms and conduct an event study around the events of 2011, as well as around previous events related to rumors about Mubarak’s health. We estimate the market valuation of political connections to be 20% to 23% of the value of connected firms. Second, we explore the mechanisms used for granting these privileges by looking at corporate behavior before 2011. It appears that these advantages allowed connected firms to increase their market size and power and their borrowings. We finally compare the performance of firms and find that the rate of return on assets of connected firms was lower than that of non-connected firms by nearly 3 percentage points. We argue that this indicates that the granting of privileges was not part of a successful industrial policy but instead, that it led to a large misallocation of capital towards less efficient firms, which together with reduced competition, led to lower economic growth.

    chekir_and_diwan_-_2015_-_crony_capitalism_in_egypt.pdf
    2014
    Hausmann, R., Ganguli, I. & Viarengo, M., 2014. Marriage, Education, and Assortative Mating in Latin America. Applied Economic Letters , 21 (12) , pp. 806-811. Publisher's VersionAbstract
    In this article, we establish facts related to marriage and education in Latin American countries. Using census data from IPUMS International, we show how marriage and assortative mating patterns have changed from 1980 to 2000 and how the patterns in Latin America compare to the United States. We find that in Latin American countries, highly educated individuals are less likely to be married than the less educated, and the pattern is stronger for women. We also show that while it has been increasing over time, there is less positive assortative mating in Latin America than in the United States.
    Hausmann, R., Ganguli, I. & Viarengo, M., 2014. Marriage, Education, and Assortative Mating in Latin America. Applied Economic Letters , 21 (12) , pp. 806-811. Publisher's VersionAbstract
    In this article, we establish facts related to marriage and education in Latin American countries. Using census data from IPUMS International, we show how marriage and assortative mating patterns have changed from 1980 to 2000 and how the patterns in Latin America compare to the United States. We find that in Latin American countries, highly educated individuals are less likely to be married than the less educated, and the pattern is stronger for women. We also show that while it has been increasing over time, there is less positive assortative mating in Latin America than in the United States.
    Hausmann, R., Ganguli, I. & Viarengo, M., 2014. Closing the gender gap in education: What is the state of gaps in labour force participation for women, wives and mothers?. International Labor Review , 153 (2) , pp. 173-207. Publisher's VersionAbstract

    The educational gender gap has closed or reversed in many countries. But what of gendered labour market inequalities? Using micro‐level census data for some 40 countries, the authors examine the labour force participation gap between men and women, the “marriage gap” between married and single women's participation, and the “motherhood gap” between mothers' and non‐mothers' participation. They find significant heterogeneity among countries in terms of the size of these gaps, the speed at which they are changing, and the relationships between them and the educational gap. But counterfactual regression analysis shows that the labour force participation gap remains largely unexplained by the other gaps.

    Contreras, V., et al., 2014. Expropriation risk and housing prices: Evidence from an emerging market. Journal of Business Research , 67 (5) , pp. 935-942. Publisher's VersionAbstract
    This paper examines the microeconomic determinants of residential real estate prices in Caracas, Venezuela, using a private database containing 17,526 transactions from 2008 to 2009. The particular institutional characteristics of many countries in Latin America, and Venezuela in particular, where land invasions and expropriations (with only partial compensation) have been common threats to property owners, provide us with an opportunity to test the effects of these risks on housing prices using a unique database. The effect of these risks on property prices is negative and significant. To our knowledge, this is the first attempt to quantify these impacts in the Hedonic pricing literature applied to real estate. Size, the number of parking spaces, the age of the property, the incidence of crime, and the average income in the neighborhood are significant determinants of prices. Finally, this paper analyzes the microeconomic determinants of housing prices at the municipal level.
    expropriation_risk_housing_prices_santos.pdf
    Pennacchioli, D., et al., 2014. The retail market as a complex system. EPJ Data Science , 3 (33). Publisher's VersionAbstract

    Aim of this paper is to introduce the complex system perspective into retail market analysis. Currently, to understand the retail market means to search for local patterns at the micro level, involving the segmentation, separation and profiling of diverse groups of consumers. In other contexts, however, markets are modelled as complex systems. Such strategy is able to uncover emerging regularities and patterns that make markets more predictable, e.g. enabling to predict how much a country’s GDP will grow. Rather than isolate actors in homogeneous groups, this strategy requires to consider the system as a whole, as the emerging pattern can be detected only as a result of the interaction between its self-organizing parts. This assumption holds also in the retail market: each customer can be seen as an independent unit maximizing its own utility function. As a consequence, the global behaviour of the retail market naturally emerges, enabling a novel description of its properties, complementary to the local pattern approach. Such task demands for a data-driven empirical framework. In this paper, we analyse a unique transaction database, recording the micro-purchases of a million customers observed for several years in the stores of a national supermarket chain. We show the emergence of the fundamental pattern of this complex system, connecting the products’ volumes of sales with the customers’ volumes of purchases. This pattern has a number of applications. We provide three of them. By enabling us to evaluate the sophistication of needs that a customer has and a product satisfies, this pattern has been applied to the task of uncovering the hierarchy of needs of the customers, providing a hint about what is the next product a customer could be interested in buying and predicting in which shop she is likely to go to buy it.

     

     

    s13688-014-0033-x.pdf
    Pritchett, L., et al., 2014. Trillions Gained and Lost: Estimating the Magnitude of Growth Episodes. CID Working Paper , 279.Abstract

    We propose and implement a new technique for measuring the total magnitude of a growth episode: the change in output per capita resulting from one structural break in the trend growth of output (acceleration or deceleration) to the next. The magnitude of the gain or loss from a growth episode combines (a) the difference between the post-break growth rate versus a counter-factual "no break" growth rate and (b) the duration of the episode to estimate the difference in output per capita at the end of an episode relative to what it would have been in the "no break" scenario. We use three "counter-factual" growth rates that allow for differing degrees of regression to global average growth: "no change" (zero regression to the mean), "world episode average" (full regression to the mean) and "unconditional predicted growth" (which uses a regression for each growth episode to predict future growth based only on past growth and episode initial level). We can also calculate the net present value at the start of an episode of the gain or loss in output comparing the actual evolution of output per capita versus a counter-factual. This method allows us to place dollar figures on growth episodes. The top 20 growth accelerations have Net Present Value (NPV) magnitude of 30 trillion dollars - twice US GDP. Conversely, the collapse in output in Iran between 1976 and 1988 produced an NPV loss of $143,000 per person. The top 20 growth decelerations account for 35 trillion less in NPV of output. Paraphrasing Lucas, once one begins to think about what determines growth events that cause the appearance or disappearance of output value equal to the total US economy, it is hard to think about anything else.

    cid_working_paper_279.pdf
    2013
    Coscia, M., Hausmann, R. & Hidalgo, C.A., 2013. The Structure and Dynamics of International Development Assistance. Journal of Globalization and Development , 3 (2) , pp. 1-42. Publisher's VersionAbstract

    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.

    2012
    Bustos, S., et al., 2012. The Dynamics of Nestedness Predicts the Evolution of Industrial Ecosystems. PLoS ONE , 7 (11) , pp. 1-8. Publisher's VersionAbstract

    In economic systems, the mix of products that countries make or export has been shown to be a strong leading indicator of economic growth. Hence, methods to characterize and predict the structure of the network connecting countries to the products that they export are relevant for understanding the dynamics of economic development. Here we study the presence and absence of industries in international and domestic economies and show that these networks are significantly nested. This means that the less filled rows and columns of these networks' adjacency matrices tend to be subsets of the fuller rows and columns. Moreover, we show that their nestedness remains constant over time and that it is sustained by both, a bias for industries that deviate from the networks' nestedness to disappear, and a bias for the industries that are missing according to nestedness to appear. This makes the appearance and disappearance of individual industries in each location predictable. We interpret the high level of nestedness observed in these networks in the context of the neutral model of development introduced by Hidalgo and Hausmann (2009). We show that the model can reproduce the high level of nestedness observed in these networks only when we assume a high level of heterogeneity in the distribution of capabilities available in countries and required by products. In the context of the neutral model, this implies that the high level of nestedness observed in these economic networks emerges as a combination of both, the complementarity of inputs and heterogeneity in the number of capabilities available in countries and required by products. The stability of nestedness in industrial ecosystems, and the predictability implied by it, demonstrates the importance of the study of network properties in the evolution of economic networks.

     

    journal.pone_.0049393.pdf

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