Journal Articles

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.

El Salvador is a star reformer. After the civil war of the 1980s, the country was able to adopt important political and institutional reforms. These included the incorporation of all political groups into the electoral process, the adoption of a new constitution, the elimination of the military police, the creation of a civilian police with members from both sides of the war, and the adoption of rules to strengthen the independence of the judiciary. On the economic front, the country consolidated its fiscal position, modernized its tax system, liberalized trade and banking, improved the regulation and supervision of its financial system, privatized most state productive assets including energy and telecommunications, and reformed its social security system in line with the Chilean model. It also expanded and granted local autonomy to the school system through the Community-Managed Schools Program (EDUCO). Finally, El Salvador dollarized its financial system in November 2000. Given the investment-grade rating earned by the country, domestic money market rates have converged to U.S. levels.

Unfortunately, El Salvador is not a star performer. Standard theory would predict that such an improvement in the institutional and regulatory environment should be followed by convergence to a higher income level. Instead, after an initial period of recovery that lasted until 1997, real gross national income per capita stagnated at levels comparable to those achieved by the country in the late 1970s. Its income relative to the United States has not recovered from the fall associated with the civil war and is just over half the ratio achieved in the late 1970s.

El Salvador is not alone in finding that reform efforts have had smaller-than-expected
growth effects. With the exception of Chile, the effects of reform ongrowth throughout Latin America have been smaller than the initial estimates carried out in the mid-1990s.In this context, El Salvador is an interesting case, since it has been particularly effective in applying wide-ranging reforms.

This paper explores why these reforms have failed to produce more growth and what can be done about it.2 We begin by placing the economic choices faced by the incoming Salvadoran administration in a regional and historical perspective. The late 1980s and early 1990s in Latin America were preceded by a decade of stagnation, but coincided with a time of unusual confidence in the future. The collapse of communism, the failure of many interventionist policies in Latin America in the 1980s, and Chile’s success gave governments a clear idea of the road they wanted to leave and the road they wanted to take. Inadequate past performance and consensus on the road ahead led to a forceful policy agenda.

For Adam Smith, wealth was related to the division of labor. As people and firms specialize in different activities, economic effi- ciency increases, suggesting that development is associated with an increase in the number of individual activities and with the complexity that emerges from the interactions between them. Here we develop a view of economic growth and development that gives a central role to the complexity of a country’s economy by interpreting trade data as a bipartite network in which countries are connected to the products they export, and show that it is possible to quantify the complexity of a country’s economy by characterizing the structure of this network. Furthermore, we show that the measures of complexity we derive are correlated with a country’s level of income, and that deviations from this relationship are predictive of future growth. This suggests that countries tend to converge to the level of income dictated by the complexity of their productive structures, indicating that development efforts should focus on generating the conditions that would allow complexity to emerge to generate sustained growth and prosperity.

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 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.

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.