Urban areas with larger and more connected populations offer an auspicious environment for contagion processes such as the spread of pathogens. Empirical evidence reveals a systematic increase in the rates of certain sexually transmitted diseases (STDs) with larger urban population size. However, the main drivers of these systemic infection patterns are still not well understood, and rampant urbanization rates worldwide makes it critical to advance our understanding on this front. Using confirmed-cases data for three STDs in US metropolitan areas, we investigate the scaling patterns of infectious disease incidence in urban areas. The most salient features of these patterns are that, on average, the incidence of infectious diseases that transmit with less ease– either because of a lower inherent transmissibility or due to a less suitable environment for transmission– scale more steeply with population size, are less predictable across time and more variable across cities of similar size. These features are explained, first, using a simple mathematical model of contagion, and then through the lens of a new theory of urban scaling. These frameworks help us reveal the links between the factors that determine the transmissibility of infectious diseases and the properties of their scaling patterns across cities.
Are regions poor because they have bad institutions or are they poor because they are disconnected from the social channels through which technology diffuses? This paper tests institutional and technological theories of economic convergence by looking at income convergence across Colombian municipalities. We use formal employment and wage data to estimate growth of income per capita at the municipal level. In Colombia, municipalities are organized into 32 departamentos or states. We use cellphone metadata to cluster municipalities into 32 communication clusters, defined as a set of municipalities that are densely connected through phone calls. We show that these two forms of grouping municipalities are very different. We study the effect on municipal income growth of the characteristics of both the state and the communication cluster to which the municipality belongs. We find that belonging to a richer communication cluster accelerates convergence, while belonging to a richer state does not. This result is robust to controlling for state fixed effects when studying the impact of communication clusters and vice versa. The results point to the importance of social interactions rather than formal institutions in the growth process.
Labor informality, associated with low productivity and lack of access to social security services, dogs developing countries around the world. Rates of labor (in)formality, however, vary widely within countries. This paper presents a new stylized fact, namely the systematic positive relationship between the rate of labor formality and the working age population in cities. We hypothesize that this phenomenon occurs through the emergence of complex economic activities: as cities become larger, labor is allocated into increasingly complex industries as firms combine complementary capabilities derived from a more diverse pool of workers. Using data from Colombia, we use a network-based model to show that the technological proximity (derived from worker transitions between industry pairs) of current industries in a city to potential new complex industries governs the growth of the formal sector in the city. The mechanism proposed has robust strong predictive power, and fares better than alternative explanations of (in)formality.
Cities thrive through the diversity of their occupants because the availability of complementary skills enables firms in the formal sector to grow, delivering increasingly sophisticated products and services. The appearance of new industries is path dependent in that new economic activities build on existing strengths, leading cities to both diversify and specialize in distinct areas. Hence, the location of necessary capabilities, and in particular the distance between firms and people with the skills they need, is key to the success of urban agglomerations. Using data for Colombia, this paper assesses the extent to which cities benefit from skills and capabilities available in their surrounding catchment areas. Without assuming a prioria a definition for cities, we sequentially agglomerate the 96 urban municipalities larger than 50,000 people based on commuting time. We show that a level of agglomeration equivalent to between 45 and 75 minutes of commuting time, corresponding to between 62 and 43 cities, maximizes the impact that the availability of skills has on the ability of agglomerations to generate formal employment. Smaller urban municipalities stand to gain more in the process of agglomeration. A range of policy implications are discussed.
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.
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.
Tourism is one of the most important economic activities in the world: for many countries it represents the single largest product in their export basket. However, it is a product difficult to chart: "exporters" of tourism do not ship it abroad, but they welcome importers inside the country. Current research uses social accounting matrices and general equilibrium models, but the standard industry classifications they use make it hard to identify which domestic industries cater to foreign visitors. In this paper, we make use of open source data and of anonymized and aggregated transaction data giving us insights about the spend behavior of foreigners inside two countries, Colombia and the Netherlands, to inform our research. With this data, we are able to describe what constitutes the tourism sector, and to map the most attractive destinations for visitors. In particular, we find that countries might observe different geographical tourists' patterns - concentration versus decentralization -; we show the importance of distance, a country's reported wealth and cultural affinity in informing tourism; and we show the potential of combining open source data and anonymized and aggregated transaction data on foreign spend patterns in gaining insight as to the evolution of tourism from one year to another.
This paper presents a descriptive analysis of wage inequality in Colombia by cities and industries and attempts to evaluate the impact of the inequality of industries on inequality of cities. Using the 2010-2014 Colombian Social Security data, we calculate the gini coefficient for cities and industries and draw comparisons between their distributions. Our results show that while cities are unequal in similar ways, industries differ widely on how unequal they can be with ginis. Moreover, industrial structure plays a significant role to determine city inequality. Industrial framework proves to be a key element in this area for researches and policymakers.
Este documento propone un nuevo marco institucional para la implementación de políticas de desarrollo productivo (PDP) en Chiapas, con el objetivo de impulsar un cambio estructural de la economía chiapaneca en búsqueda de mayor diversidad y complejidad productiva.
La primera sección contiene un diagnóstico del contexto actual de PDP en el Estado. Se observa un bajo grado de implementación y ejecución, pese a la abundancia de análisis, prescripciones e iniciativas de apoyo a la empresa privada. Esta situación no se puede atribuir a la escasez de recursos. Aunque a nivel estatal no se dispone de muchos recursos para PDP, sí los hay al nivel de programas federales existentes. Se trata de deficiencias de coordinación y liderazgo en el sector público, que interactúan con problemas de coordinación dentro del propio sector privado, con la percepción de inestabilidad político-institucional, y con una historia de desconfianza, para conformar un escenario de escasa colaboración a distintos niveles, por lo que muchas de las oportunidades existentes quedan desaprovechadas.
La segunda sección describe los fundamentos conceptuales para un nuevo marco institucional que haga posible la implementación efectiva de PDP, reflejados en cuatro principios básicos. Primero, el nuevo marco debe construirse con relativamente pocos recursos presupuestarios del Estado. Segundo, se subraya que debe centrarse en la coordinación entre sector público y sector privado, lo que requiere capacidades y conocimientos específicos dentro del sector público, la construcción de una relación de confianza, y la promoción proactiva de la organización y coordinación del sector privado. Tercero, un énfasis en la provisión de bienes y servicios públicos, y no intervenciones de mercado. Cuarto, la promoción de un proceso dinámico iterativo.
Una vez establecidos los principios, en la tercera sección se detalla la propuesta concreta de coordinación para la implementación del nuevo marco institucional. Se centra ella en los siguientes cinco puntos. Primero, la designación de un ente implementador sobre el cual recaiga con claridad el liderazgo y la responsabilidad del proceso de implementación de PDP. Segundo, se recomienda dotar a dicho ente de un staff técnicamente competente. Tercero, debe tener autonomía política. Cuarto, debe ser proactivo, en un proceso de dinamización orientado a la acción. Por último, debe fomentar el liderazgo en el sector privado. Al final, se discuten ejemplos ilustrativos de cómo se podría dar la implementación práctica de ese proceso dinámico.
We examine in this paper the relation between government size and capital and labor openness employing a panel of the 32 Mexican states over the period 1996-2006. Making use of two alternative measures of capital and labor openness and employing several alternative econometric specifications, we first find systematic positive effects of our openness measures on the size of the states’ total government spending. Thereafter, we break down total government expenditure and focus on three subcategories of spending associated with social welfare: education, health and poverty alleviation programs. We find that FDI flows, our proxy for capital openness, are not significant determinants of the state’s social spending, but labor openness, in the form of international migration, has a significant and even greater impact on some of the aforementioned categories than on total spending.