Coscia, M., et al., 2020. The Node Vector Distance Problem in Complex Networks. ACM Computing Surveys , 53 (6). Publisher's VersionAbstract

We describe a problem in complex networks we call the Node Vector Distance (NVD) problem, and we survey algorithms currently able to address it. Complex networks are a useful tool to map a non-trivial set of relationships among connected entities, or nodes. An agent—e.g., a disease—can occupy multiple nodes at the same time and can spread through the edges. The node vector distance problem is to estimate the distance traveled by the agent between two moments in time. This is closely related to the Optimal Transportation Problem (OTP), which has received attention in fields such as computer vision. OTP solutions can be used to solve the node vector distance problem, but they are not the only valid approaches. Here, we examine four classes of solutions, showing their differences and similarities both on synthetic networks and real world network data. The NVD problem has a much wider applicability than computer vision, being related to problems in economics, epidemiology, viral marketing, and sociology, to cite a few. We show how solutions to the NVD problem have a wide range of applications, and we provide a roadmap to general and computationally tractable solutions. We have implemented all methods presented in this article in a publicly available open source library, which can be used for result replication.

Goldstein, P., 2020. Pathways for Productive Diversification in Ethiopia,Abstract

Ethiopia will need to increase the diversity of its export basket to guarantee a sustainable growth path. Ethiopia has shown stellar growth performance throughout the last two decades, but, in this period, export growth has been insufficient to finance the country’s balance of payments needs. As argued in our Growth Diagnostic report,1 Ethiopia’s growth decelerated as a result of the increasing external imbalances which have resulted in a foreign exchange constraint. This macroeconomic imbalance is now slowing the rate of economic growth, job creation and poverty alleviation across the country. Although export growth will not be rapid enough to address the foreign exchange constraint on its own in the short-term, the only way for the country to achieve macroeconomic balance as it grows in the longer term is to increase its exports per capita. With only limited opportunities to expand its exports on the intensive margin, the Government of Ethiopia (GoE) will have to strategically support the diversification of its economy to expand its exports base.

This report applies the theory of Economic Complexity in order to describe the base of productive knowhow and assess the opportunities and constraints to diversification in Ethiopia’s economy. The theory of Economic Complexity offers tools to capture and quantitatively estimate the diversity and sophistication of productive knowhow in an economy and to analyze the potential to develop comparative advantage in new industries. These tools provide valuable inputs for informing diversification strategies and the use of state resources by providing rigorous information on the risks and potential returns of government industrial policies in support of different sectors.

Hausmann, R., et al., 2020. Diagnóstico de Crecimiento de Loreto: Principales Restricciones al Desarrollo Sostenible.Abstract

Sembrado en el flanco oeste de la selva amazónica, Loreto se encuentra entre los departamentos más pobres y con peores indicadores sociales del Perú. El desarrollo enfrenta allí un sinfín de barreras, pero no todas son igualmente limitantes y tampoco hay recursos para atender todos los problemas a la vez. El Laboratorio de Crecimiento de la Universidad de Harvard, bajo el auspicio de la Fundación Gordon and Betty Moore, ha desarrollado un Diagnóstico de Crecimiento que buscar identificar las restricciones más limitantes, y priorizar las intervenciones de políticas públicas alrededor de un número reducido de factores con el mayor impacto. La investigación, que se fundamenta en análisis de bases de datos nacionales e internacionales, e incluye factores cuantitativos y cualitativos derivados de las visitas de campo, identifica a la conectividad de transporte, los problemas de coordinación asociados al autodescubrimiento, y la energía eléctrica, como las restricciones más vinculantes para el desarrollo de Loreto. De acuerdo con nuestras conclusiones, mejoras en la provisión de estos tres factores tendrían un mayor impacto sobre el desarrollo sostenible de la región que mejores en la educación y los niveles de capital humano, el acceso a financiamiento, y otros sospechosos habituales. Este reporte es el segundo de una investigación más amplia – Transformación estructural y restricciones limitantes a la prosperidad en Loreto, Perú – que busca aportar insumos para el desarrollo de políticas públicas a escala nacional y regional que contribuyan a promover el desarrollo productivo y la prosperidad de la región.

Hartog, M., Lopez-Cordova, J.E. & Neffke, F., 2020. Assessing Ukraine's Role in European Value Chains: A Gravity Equation-cum-Economic Complexity Analysis Approach.Abstract
We analyze Ukraine's opportunities to participate in European value chains, using traditional gravity models, combined with tools from Economic Complexity Analysis to study international trade (exports) and Foreign Direct Investment (FDI). This toolbox is shown to be predictive of the growth and entry of new exports to the EU's Single Market, as well as foreign direct investments from the Single Market in Ukraine. We find that Ukraine has suffered from a decline of trade with Russia, which has led not only to a quantitative but also a qualitative deterioration in Ukrainian exports. Connecting to western European value chains is in principle possible, with several opportunities in the automotive, information technology and other sectors. However, such a shift may lead to a spatial restructuring of the Ukrainian economy and a mismatch between the geographical supply of and demand for labor.
Schetter, U. & Tejada, O., 2020. On Globalization and the Concentration of Talent: A General Result on Superstar Effects and Matching.Abstract
We analyze how globalization affects the allocation of talent across competing teams in large matching markets. Focusing on amplified superstar effects, we show that a convex transformation of payoffs promotes positive assortative matching. This result holds under minimal assumptions on how skills translate into competition outcomes and how competition outcomes translate into payoffs. Our analysis covers many interesting special cases, including simple extensions of Rosen (1981) and Melitz (2003) with competing teams. It also provides new insights on the distributional consequences of globalization, and on the role of technological change, urban agglomeration, and taxation for the composition of teams.
revised October 2020
Hausmann, R., et al., 2020. La Riqueza Escondida de Loreto: Análisis de Complejidad Económica y Oportunidades de Diversificación Productiva.Abstract

El Laboratorio de Crecimiento de la Universidad de Harvard, bajo el auspicio de la Fundación Gordon and Betty Moore, ha desarrollado esta investigación para identificar las capacidades productivas existentes en Loreto y las actividades económicas con potencial para liderar la transformación estructural de su economía. Este reporte forma parte de una investigación más amplia – Transformación estructural y restricciones limitantes a la prosperidad en Loreto, Perú – que busca aportar insumos para el desarrollo de políticas públicas a escala nacional y regional que contribuyan a promover el desarrollo productivo y la prosperidad de la región, tomando en cuenta sus características particulares.

2020-10-cid-wp-386-economic-complexity-loreto-es.pdf 2021-03-cid-wp-386-economic-complexity-loreto-en.pdf.pdf
Hausmann, R., et al., 2020. Emerging Cities as Independent Engines of Growth: The Case of Buenos Aires.Abstract

What does it take for a sub-national unit to become an autonomous engine of growth? This issue is particularly relevant to large cities, as they tend to display larger and more complex know-how agglomerations and may have access to a broader set of policy tools. To approximate an answer to this question, specific to the case of Buenos Aires, Harvard’s Growth Lab engaged in a research project from December 2018 to June 2019, collaborating with the Center for Evidence-based Evaluation of Policies (CEPE) of Universidad Torcuato di Tella, and the Development Unit of the Secretary of Finance of the City of Buenos Aires. Together, we have developed research agenda that seeks to provide inputs for a policy plan aimed at decoupling Buenos Aires’s growth trajectory from the rest of Argentina’s.

Listen to the Growth Lab Podcast interview with the authors. 

Lora, E., 2020. Income Changes after Inter-city Migration.Abstract
Using panel data for workers who change jobs, changes in several labor outcomes after inter-city migration are estimated by comparing workers in similar circumstances who move to a new city –the treatment group—with those who stay in the same city –the control group. After matching the two groups using Mahalanobis distances over a wide range of covariates, the methodology of “difference-in-difference treatment effects on the treated” is used to estimate changes after migration. On average, migrants experience income gains but their dedication to formal employment becomes shorter. Income changes are very heterogenous, with low-wage workers and those formerly employed by small firms experiencing larger and more sustained gains. The propensity to migrate by groups of sex, age, wage level, initial dedication, initial firm size and size of city of origin is significantly and directly correlated with the expected cumulative income gains of migration, and inversely with the uncertainty of such gains.
Zhao, D., Chen, Y. & Shen, J.H., 2020. Mortgage Payments and Household Consumption in Urban China. Economic Modelling , 93 , pp. 100-111. Publisher's VersionAbstract

By exploiting variation both in mortgage payoffs and mortgage interest rate resets, we find that a decline in mortgage payments induces a significant increase in nondurable goods spending, even when households have substantial amounts of liquidity. Following mortgage payoff, households increase consumption expenditures by 61% of the original payment. In comparison, households increase consumption by only 36% in response to a transitory payment adjustment induced by interest rate changes. Households with a higher payment-to-income ratio have a significantly lower marginal propensity to consume (MPC). These results have practical implications for policy markers seeking to design consumption boosting policies and are important for understanding how changes in monetary policy may affect consumer spending patterns.

Knowledge Diffusion in the Network of International Business Travel
Coscia, M., Neffke, F. & Hausmann, R., 2020. Knowledge Diffusion in the Network of International Business Travel. Nature Human Behaviour , 4 (10). Publisher's VersionAbstract

We use aggregated and anonymized information based on international expenditures through corporate payment cards to map the network of global business travel. We combine this network with information on the industrial composition and export baskets of national economies. The business travel network helps to predict which economic activities will grow in a country, which new activities will develop and which old activities will be abandoned. In statistical terms, business travel has the most substantial impact among a range of bilateral relationships between countries, such as trade, foreign direct investments and migration. Moreover, our analysis suggests that this impact is causal: business travel from countries specializing in a specific industry causes growth in that economic activity in the destination country. Our interpretation of this is that business travel helps to diffuse knowledge, and we use our estimates to assess which countries contribute or benefit the most from the diffusion of knowledge through global business travel.

Additional content:

Santos, M., et al., 2020. Albania's Industry Targeting Dashboard. Publisher's VersionAbstract
This industry targeting tool is custom-made for Albania. Users can choose any of 272 industries (based on NACE Rev. 2 industry codes) from the above drop-down list and explore the industry’s match with Albania’s current productive capabilities and comparative advantages and disadvantages. The tool is designed for use by government and non-government entities that seek to attract foreign direct investment (FDI) to Albania to accelerate economic development. Harvard Growth Lab research in Albania shows that the long-term pace of economic growth will be determined by the pace at which the country can absorb new economic activities and productive capabilities from abroad. Detailed information on the methodology and data sources used in this tool can be found here. This tool can be used in combination with the Growth Lab’s Atlas of Economic Complexity to explore patterns in global trade in very high detail.
O'Brien, T. & Lu, J., 2020. Can Albania’s Economic Turnaround Survive COVID-19? A Growth Diagnostic Update. The Growth Lab's VizHub. Publisher's VersionAbstract
The Growth Lab, which works with countries to identify obstacles to growth and propose targeted policy solutions, has been conducting applied research in Albania since 2013. This brief analysis takes stock of Albania’s economic growth prior to the COVID-19 crisis and what the strengths and weaknesses of the pre-COVID economy imply for recovery and the possibility of accelerating long-term and inclusive growth in the years to come. Albania is a place where much has been achieved to expand opportunity and well-being as growth has gradually accelerated since 2013-14, but where much remains to be done to continue this acceleration once the immediate crisis of COVID-19 has passed.
Hausmann, R. & Schetter, U., 2020. Horrible Trade-offs in a Pandemic: Lockdowns, Transfers, Fiscal Space, and Compliance.Abstract

In this paper, we develop a heterogeneous agent general equilibrium framework to analyze optimal joint policies of a lockdown and transfer payments in times of a pandemic. In our model, the effectiveness of a lockdown in mitigating the pandemic depends on endogenous compliance. A more stringent lockdown deepens the recession which implies that poorer parts of society find it harder to subsist. This reduces their compliance with the lockdown, and may cause deprivation of the very poor, giving rise to an excruciating trade-off between saving lives from the pandemic and from deprivation. Lump-sum transfers help mitigate this trade-off. We identify and discuss key trade-offs involved and provide comparative statics for optimal policy. We show that, ceteris paribus, the optimal lockdown is stricter for more severe pandemics and in richer countries. We then consider a government borrowing constraint and show that limited fiscal space lowers the optimal lockdown and welfare, and increases the aggregate death burden during the pandemic. We finally discuss distributional consequences and the political economy of fighting a pandemic.

Additional readings:

Cortes, P., Kasoolu, S. & Pan, C., 2020. Labor Market Nationalization Policies and Firm Outcomes: Evidence from Saudi Arabia.Abstract
Saudi Arabia is home to the world’s third largest migrant population. Under mounting pressure to increase the private sector employment of Saudis during the last decade, a series of nationalization policies on the labor force have been imposed since late 2011. In this paper, we study how the first nationalization policy, Nitaqat, affected the overall labor market and non-oil firms in the private sector, especially exporting firms. Our rich and novel data allow us to assess the effect of the policy on a wide set of outcomes: employment decisions by composition and size, the output and productivity of exporting firms, labor costs, and exit from the market. Using a difference-in-difference analysis, we compare the 2011 to 2012 change in outcomes between firms above and firms below the threshold required for the minimum share of Saudi workers in a firm. Our results suggest that the policy succeeded in encouraging firms to increase the share of Saudis in private firms. It also increased the share of Saudi women in the workforce, suggesting that the policy had a positive effect on increasing female labor force participation. However, these gains came at a very high cost to firms: our findings suggest that the policy led to a reduced firm size, reduced productivity and output of exporting firms, increased wage bill, increased share of low-skilled Saudi workers, and higher firm exit rates.
Gadgin Matha, S., Goldstein, P. & Lu, J., 2020. Air Transportation and Regional Economic Development: A Case Study for the New Airport in South Albania.Abstract

Considering the case of the proposed airport in Vlora, South Albania, this report analyzes the channels through which a new greenfield airport can contribute to regional economic development. In December 2019, the Government of Albania opened a call for offers to build a new airport in the south of the country. While there is evidence indicating that the airport could be commercially viable, this does not provide a grounded perspective on the channels by which the airport could boost the regional economy. To evaluate how the new airport would interact with existing and potential economic activities, this report evaluates three of the most important channels of impact by which the airport could serve as a promoter: (1) economic activities directly related to or promoted by airports, (2) the airport’s potential contribution to the region’s booming tourism sector and (3) the potential for the country’s development of air freight as a tool for export promotion. In each of these three cases, the report identifies complementary public goods or policies that could maximize the airport’s impact in the region.

The operation of the airport itself could stimulate a series of economic activities directly related to air traffic services. Airports have the ability to mold the economic structure of the places immediately around them, acting both as a consumer and as a supplier of air transport services. Not only activities related to transportation and logistics thrive around airports, but also a variety of manufacturing, trade and construction industries. Nevertheless, the agglomeration benefits of a successful aerotropolis are not guaranteed by the construction of an airport. For South Albania’s new airport to actualize its potential returns, integrated planning of the airport site will be required, with focus on real estate planification and provision of complementary infrastructure.

Establishing an airport in Vlora has the potential to spur regional development in South Albania through facilitating the growth of the tourism sector and its related activities. Albania’s tourism industry has seen strong growth in the last two decades, but still lags behind its potential. Albania only has a strong penetration in the tourism market of its neighboring markets, and the high seasonality of the tourism season further limits the sector’s growth. The establishment of an airport in South Albania would ease some of the tourism industry constraints tied to transportation into the country and region. Given the high reliance of the tourism industry on its many complementary inputs, more than one area of concern may have to be addressed for the impact of the new airport to be maximized. Facilitating transportation access around the South Albania region and specifically to tourist sites; preparing natural and cultural heritage sites for tourism use and expanding tourism infrastructure to accommodate potential growth are some of the interventions analyzed.

Airfreight infrastructure could in theory provide opportunities to improve the competitiveness of Albanian exports but developing a successful air cargo cluster is no simple task. An airport can facilitate an alternative mode of transport for specific types of goods and hence promote a country’s exports. In Albania’s case, not only existing textile and agriculture products could be competitively exported through air freight, but also air freight itself could improve Albania’s position to diversify into “nearby” industries, identified by the theory of Economic Complexity. Nevertheless, an effective air freight strategy does not and cannot uniquely depend on the simple availability of a nearby airport. Air cargo operations require both traffic volume that Albania may not be able to provide, as well as complementary cargo-specific infrastructure. Although the potential for air freight in South Albania could be high, it is by no means a safe bet nor does it imply with certainty significant impact in the immediate future.

Levy-Yeyati, E. & Montane, M., 2020. Specificity of Human Capital: An Occupation Space Based on Job-to-Job Transitions.Abstract
Using job transition data from Argentina’s Household Survey, we document the extent to which human capital is specific to occupations and activities. Based on workers’ propensity to move between occupations/industries, we build Occupation and Industry Spaces to illustrate job similarities, and we compute an occupation and industry similarity measures that, in turn, we use to explain wage transition dynamics. We show that our similarity measures influence positively post-transition wages. Inasmuch as wages capture a worker´s marginal productivity and this productivity reflects the degree to which a worker matches the job’s skill demand, our results indicate that a worker´s human capital is specific to both occupation and activity: closer occupations share similar skill demands and task composition (in other words, demand similar workers) and imply a smaller human capital loss in the event of a transition.
Revised May 2020.
Ganguli, I., Hausmann, R. & Viarengo, M., 2020. Gender Differences in Professional Career Dynamics: New Evidence from a Global Law Firm.Abstract

We examine gender gaps in career dynamics in the legal sector using rich panel data from one of the largest global law firms in the world. The law firm studied is representative of multinational law firms and operates in 23 countries. The sample includes countries at different stages of development. We document the cross-country variation in gender gaps and how these gaps have changed over time. We show that while there is gender parity at the entry level in most countries by the end of the period examined, there are persistent raw gender gaps at the top of the organization across all countries. We observe significant heterogeneity among countries in terms of gender gaps in promotions and wages, but the gaps that exist appear to be declining over the period studied. We also observe that women are more likely to report exiting the firm for family and work-life balance reasons, while men report leaving for career advancement. Finally, we show that various measures of national institutions and culture appear to play a role in the differential labor-market outcomes of men and women.

Schetter, U., 2020. Quality Differentiation, Comparative Advantage, and International Specialization Across Products.Abstract

We introduce quality differentiation into a Ricardian model of international trade. We show that (1) quality differentiation allows industrialized countries to be active across the full board of products, complex and simple ones, while developing countries systematically specialize in simple products, in line with novel stylized facts. (2) Quality differentiation may thus help to explain why richer countries tend to be more diversified and why, increasingly over time, rich and poor countries tend to export the same products. (3) Quality differentiation implies that the gains from inter-product trade mostly accrue to developing countries. (4) Guided by our theory, we use a censored regression model to estimate the link between a country’s GDP per capita and its export quality. We find a much stronger relationship than when using OLS, in line with our theory.

Bahar, D., Rapoport, H. & Turati, R., 2020. Does Birthplace Diversity Affect Economic Complexity? Cross-country Evidence.Abstract
We empirically investigate the relationship between a country’s economic complexity and the diversity in the birthplaces of its immigrants. Our cross-country analysis suggests that countries with higher birthplace diversity by one standard deviation are more economically complex by 0.1 to 0.18 standard deviations above the mean. This holds particularly for diversity among highly educated migrants and for countries at intermediate levels of economic complexity. We address endogeneity concerns by instrumenting diversity through predicted stocks from a pseudo-gravity model as well as from a standard shift-share approach. Finally, we provide evidence suggesting that birthplace diversity boosts economic complexity by increasing the diversification of the host country’s export basket.
Bahar, D., Choudhury, P. & Rapoport, H., 2020. Migrant Inventors and the Technological Advantage of Nations.Abstract

We investigate the relationship between the presence of migrant inventors and the dynamics of innovation in the migrants’ receiving countries. We find that countries are 25 to 60 percent more likely to gain advantage in patenting in certain technologies given a twofold increase in the number of foreign inventors from other nations that specialize in those same technologies. For the average country in our sample, this number corresponds to only 25 inventors and a standard deviation of 135. We deal with endogeneity concerns by using historical migration networks to instrument for stocks of migrant inventors. Our results generalize the evidence of previous studies that show how migrant inventors "import" knowledge from their home countries, which translates into higher patenting in the receiving countries. We interpret these results as tangible evidence of migrants facilitating the technology-specific diffusion of knowledge across nations.