Research and Policy Impact (2024)

M. Esfahani, J. Fernald, B. Hobijn (2024), "World Productivity: 1996–2014", American Economic Journal: Macroeconomics, 16(3), pp. 160-189

We use a new growth accounting method to quantify the drivers of world total factor productivity (TFP) growth during 1996–2014 and uncover four main results. World productivity growth is volatile from year to year. This mainly reflects reallocation of labor across country-industries. The contribution of country-industry level productivity growth to world productivity is relatively constant over time. This constancy masks that the increased importance of emerging economies offsets a productivity slowdown in advanced economies. After 2008, this offsetting effect dissipated and world TFP growth declined. These conclusions are robust to the inclusion of markups in the analysis.

We study the joint evolution of the sectoral composition and the investment rate of developing economies. Using panel data for several countries in different stages of development, we document three novel facts: (a) the share of industry and the investment rate are strongly correlated and follow a hump-shaped profile with development, (b) investment goods contain more domestic value added from industry and less from services than consumption goods do, and (c) the evolution of the sectoral composition of investment and consumption goods differs from the one of GDP. We build a multi-sector growth model to fit these patterns and provide two important results. First, the hump-shaped evolution of investment demand explains half of the hump in industry with development. Second, asymmetric sectoral productivity growth helps explain the decline in the relative price of investment goods along the development path, which in turn increases capital accumulation and promotes growth.

The relative price of services rises with development. A standard interpretation of this fact is that productivity differences across countries are larger in manufacturing than in services. The service sector comprises heterogeneous categories and we document that many disaggregated service categories feature a negative income elasticity of relative prices. We divide service industries into two broad categories based on the income gradient of its relative price: traditional services with positive income elasticities and nontraditional services with negative income elasticities of relative prices. Using an otherwise standard multisector development accounting framework extended to include an input–output structure, we find that the cross-country income elasticity of sectoral productivity is large in nontraditional services (1.15), smaller in manufacturing (1.05), and much smaller in traditional services (0.67). Eliminating cross-country productivity differences in nontraditional services reduces aggregate income disparity by 58%, a 7.9-fold reduction in aggregate productivity differences. Heterogeneity between traditional and nontraditional services also has a substantial impact on aggregate productivity.

This paper develops a multi‐stage general‐equilibrium model of global value chains (GVCs) and studies the specialization of countries within GVCs in a world with barriers to international trade. With costly trade, the optimal location of production of a given stage in a GVC is not only a function of the marginal cost at which that stage can be produced in a given country, but is also shaped by the proximity of that location to the precedent and the subsequent desired locations of production. We show that, other things equal, it is optimal to locate relatively downstream stages of production in relatively central locations. We also develop and estimate a tractable, quantifiable version of our model that illustrates how changes in trade costs affect the extent to which various countries participate in domestic, regional, or global value chains, and traces the real income consequences of these changes.

On June 23, 2016, the United Kingdom voted to leave the European Union. The trade policies that will replace E.U. membership are uncertain, however, and speculation abounds that this uncertainty will cause immediate harm to the U.K. economy. In this paper, I use a dynamic general equilibrium model with heterogeneous firms, endogenous export participation, and stochastic trade costs to quantify the impact of uncertainty about post-Brexit trade policies. I find that the total consumption-equivalent welfare cost of Brexit for U.K. households is between 0.4 and 1.2%, but less than a quarter of a percent of this cost is due to uncertainty.

We document that international input-output linkages contribute substantially to synchronizing producer price inflation (PPI) across countries. Using a multicountry, industry-level data set that combines information on PPI and exchange rates with global input-output linkages, we recover the underlying cost shocks that are propagated internationally via the global input-output network, thus generating the observed dynamics of PPI. We then compare the extent to which common global factors account for the variation in actual PPI and in the underlying cost shocks. Across a range of econometric tests, input-output linkages account for half of the global component of PPI inflation.

Intermediate-input intensities vary systematically with economic development across countries. These cross-country differences in input–output linkages account for 74% of the curvature in the hump shape in industry’s share in value added across levels of income per capita. This is twice as much as can be accounted for by variation in the composition of final demand. Using a three-sector, open-economy model of structural change I find that this result is robust to general equilibrium effects.

Between 1990 and 2008, air pollution emissions from U.S. manufacturing fell by 60 percent despite a substantial increase in manufacturing output. We show that these emissions reductions are primarily driven by within-product changes in emissions intensity rather than changes in output or in the composition of products produced. We then develop and estimate a quantitative model linking trade with the environment to better understand the economic forces driving these changes. Our estimates suggest that the implicit pollution tax that manufacturers face doubled between 1990 and 2008. These changes in environmental regulation, rather than changes in productivity and trade, account for most of the emissions reductions.

In macroeconomic models, the elasticity of substitution between clean and dirty energy inputs within the energy aggregate is a central parameter in assessing the necessary conditions for long-run green growth. Using new sectoral data in a panel of 26 countries, we formulate specifications of nested constant elasticity of substitution production functions that allow estimating this parameter for the first time. We present evidence that it significantly exceeds unity, a favorable condition for promoting green growth.

We develop a methodology to construct nonparametric counterfactual predictions, free of functional form restrictions on preferences and technology, in neoclassical models of international trade. First, we establish the equivalence between such models and reduced exchange models in which countries directly exchange factor services. This equivalence implies that, for an arbitrary change in trade costs, counterfactual changes in the factor content of trade, factor prices, and welfare only depend on the shape of a reduced factor demand system. Second, we provide sufficient conditions under which estimates of this system can be recovered nonparametrically. Together, these results offer a strict generalization of the parametric approach used in so-called gravity models. Finally, we use China's recent integration into the world economy to illustrate the feasibility and potential benefits of our approach.

Individuals that consume different baskets of goods are differentially affected by relative price changes caused by international trade. We develop a methodology to measure the unequal gains from trade across consumers within countries. The approach requires data on aggregate expenditures and parameters estimated from a nonhom*othetic gravity equation. We find that trade typically favors the poor, who concentrate spending in more traded sectors.

M.P. Timmer, A.A. Erumban, B. Los, R. Stehrer and G.J. de Vries (2014), "Slicing Up Global Value Chains", Journal of Economic Perspectives, 28(2), pp. 99-118

In this paper, we "slice up the global value chain" using a decomposition technique that has recently become feasible due to the development of the World Input-Output Database. We trace the value added by all labor and capital that is directly and indirectly needed for the production of final manufacturing goods. The production systems of these goods are highly prone to international fragmentation as many stages can be undertaken in any country with little variation in quality. We seek to establish a series of facts concerning the global fragmentation of production that can serve as a starting point for future analysis. We describe four major trends. First, international fragmentation, as measured by the foreign value-added content of production, has rapidly increased since the early 1990s. Second, in most global value chains there is a strong shift towards value being added by capital and high-skilled labor, and away from less-skilled labor. Third, within global value chains, advanced nations increasingly specialize in activities carried out by high-skilled workers. Fourth, emerging economies surprisingly specialize in capital-intensive activities.