We use a new firm-level dataset that establishes the location, ownership, and activity of 650,000 multinational subsidiaries. Using a combination of four-digit-level information and input-output tables, we find the share of vertical FDI (subsidiaries that provide inputs to their parent firms) to...

Do intellectual property rights influence multinationals' manufacturing location decisions? My theoretical model indicates that countries with strong patent laws attract multinational activity, but only in sectors with relatively long product life cycles. By contrast, firms with short life-cycle...

We present a theory of spatial development. Manufacturing and services firms located in a continuous geographic area choose each period how much to innovate. Firms trade subject to transport costs and technology diffuses spatially. We apply the model to study the evolution of the US economy in...

Why do firms cluster near one another? We test Marshall's theories of industrial agglomeration by examining which industries locate near one another, or coagglomerate. We construct pairwise coagglomeration indices for US manufacturing industries from the Economic Census. We then relate...

This paper develops microfoundations for the role that diversified cities play in fostering innovation. A simple model of process innovation is proposed, where firms learn about their ideal production process by making prototypes. We build around this a dynamic general-equilibrium model, and...

I discuss the measurement of world poverty and inequality, with particular attention to the role of purchasing power parity (PPP) price indexes from the International Comparison Project. Global inequality increased with the latest revision of the ICP, and this reduced the global poverty line...