Technological diversification

Economies at early stages of development are often shaken by abrupt changes in growth rates, whereas in advanced economies growth rates tend to be relatively stable. To explain this pattern, we propose a theory of technological diversification. Production makes use of different input varieties, which are subject to imperfectly correlated shocks. Technological progress takes the form of an increase in the number of varieties, raising average productivity. In addition, the expansion in the number of varieties in our model provides diversification benefits against variety-specific shocks and it can hence lower the volatility of output growth. Technological complexity evolves endogenously in response to profit incentives. The decline in volatility thus arises as a by-product of firms’ incentives to increase profits and is hence a likely outcome of the development process. We quantitatively asses the predictions of the model in light of the empirical evidence and find that for reasonable parameter values, the model can generate a decline in volatility with the level of development comparable to that in the data.

A Spatial Explanation for the Balassa-Samuelson Effect

We propose a simple spatial model to explain why the price level is higher in rich countries. There are two sectors: manufacturing, which is freely tradable, and non-tradable services, which have to locate near customers in big cities. As countries develop, total factor productivity increases simultaneously in both sectors. However, because services compete with the population for scarce land, labor productivity will grow slower in services than in manufacturing. Services become more expensive, and the aggregate price level becomes higher. The model hence provides a theoretical foundation for the Balassa--Samuelson assumption that productivity growth is slower in the non-tradable sector than in the tradable sector. Empirical results confirm two key implications of the theory. First, we compare countries where land is scarce (densely populated, highly urban countries) to rural countries. The Balassa--Samuelson effect is stronger among urban countries. Second, we compare sectors that locate at different distance to consumers. The Balassa--Samuelson effect is stronger within sectors that locate closer to consumers.

Lumpy Trade and the Welfare Effects of Administrative Barriers

Using detailed U.S. and Spanish export data, we document that administrative trade costs of per shipment nature (documentation, customs clearance and inspection) lead to less frequent and larger-sized shipments, i.e. more lumpiness, in international trade. We build a model to analyze these effects and their welfare consequences. Exporters decide not only how much to sell at a given price, but also how to break up total trade into individual shipments. Consumers value frequent shipments, because they enable them to consume close to their preferred dates. Having fewer shipments hence entails a welfare cost. Calibrating the model to observed shipping frequencies and per-shipment costs, we show that countries would gain 2--3 percent of their GDP by eliminating such barriers. This suggests that trade volumes alone are insufficient to understand the gains from trade.

Machines and machinists: Capital-skill complementarity from an international trade perspective

We estimate the effect of imported machines on the wages of machine operators utilizing Hungarian linked employer-employee data. We infer exposure to imported machines from detailed trade statistics of the firm and the occupation description of the worker. We find that workers exposed to imported machines earn about 8 percent higher wages than other machine operators at the same firm. When we proxy for unobserved worker characteristics, we find a significant 3 percent wage premium, suggesting that the relationship is causal. The return to schooling is also higher on imported machines. We build a simple matching model consistent with these findings. Our findings suggest that machine imports can be an important channel through which skill-biased technical change reaches less developed and emerging economies.

Technological diversification

Why is GDP so much more volatile in poor countries than in rich ones? To answer this question, we propose a theory of technological diversification. Production makes use of different input varieties, which are subject to imperfectly correlated shocks. As in endogenous growth models, technological progress increases the number of varieties, raising average productivity. In our model, the expansion in the number of varieties provides diversification benefits against variety-specific shocks and it hence lowers the volatility of output. Technological complexity evolves endogenously in response to profit incentives. Complexity (and hence output stability) is positively related with the development of the country, the comparative advantage of the sector, and the sector’s skill and technology intensity. Using sector-level data for a broad sample of countries, we provide extensive empirical evidence confirming the cross-country and cross-sectoral predictions of the model. JEL Classification: O11, O14, O41, E32diversification, economic fluctuations, specialization, technology choice

Economies of Scale and the Size of Exporters

Exporters are few---less than one fifth among U.S. manufacturing firms---and are larger than non-exporting firms---about 4-5 times more total sales per firm. These facts are often cited as support for models with economies of scale and firm heterogeneity as in Melitz (2003). We find that the basic Melitz model cannot simultaneously match the size and share of exporters given the observed distribution of total sales. Instead exporters are expected to be between 90 and 100 times larger than non-exporters. It is easy to reconcile the model with the data. However, a lot of variation independent of firm size is needed to do so. This suggests that economies of scale play only a minor role in determining the export status of a firm. We show that the augmented model also has markedly different implications in the event of a trade liberalization. Most of the adjustment is through the intensive margin; and productivity gains due to reallocation are halved.

Imported Inputs and Productivity

We estimate a model of importers in Hungarian micro data and conduct counterfactual policy analysis to investigate the effect of imports on productivity. We find that importing all foreign varieties would increase firm productivity by 12 percent, almost two-fifths of which is due to imperfect substitution between foreign and domestic goods. The effectiveness of import use is higher for foreign firms and increases when a firm becomes foreign-owned. Our estimates imply that during 1993-2002 one-third of the productivity growth in Hungary was due to imported inputs. Simulations show that the productivity gain from a tariff cut is largest when the economy has many importers and many foreign firms, implying policy complementarities between tariff cuts, dismantling non-tariff barriers, and FDI liberalization.

Administrative barriers to trade

We build a model of administrative barriers to trade to understand how they affect trade volumes, shipping decisions and welfare. Because administrative costs are incurred with every shipment, exporters have to decide how to break up total trade into individual shipments. Consumers value frequent shipments, because they enable them to consume close to their preferred dates. Hence per-shipment costs create a welfare loss.We derive a gravity equation in our model and show that administrative costs can be expressed as bilateral ad-valorem trade costs. We estimate the ad-valorem equivalent in Spanish shipment-level export data and find it to be large. A 50% reduction in per-shipment costs is equivalent to a 9 percentage point reduction in tariffs. Our model and estimates help explain why policy makers emphasize trade facilitation and why trade within customs unions is larger than trade within free trade areas. © 2015 The Authors

Per-shipment costs and the lumpiness of international trade

Using detailed U.S. and Spanish export data, we document that trade costs of a per-shipment nature are associated with less frequent and larger shipments (i.e., more lumpiness) in international trade. This finding is pervasive across broad product categories, but most apparent for industrial supplies, parts and accessories, and food products. © 2015 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology