This paper provides a simple and empirically plausible model of artworks as investment vehicles. It reconciles the observation that average financial returns for collectibles are low and volatile with the theory of consumption-based asset pricing. Art assets are appealing both for their ability to transfer consumption over time and for their use as signals of wealth, as in the literature on the demand for luxuries. Adding art value to utility, returns also reflect this "conspicuous consumption" dividend; as a result, average financial returns are low. Risk premia for artworks are predicted to be modest or even negative. (JEL G11, Z11)

In this paper, we show that the substitution of imported for domestically produced goods and services—often known as offshoring—can lead to overestimates of U.S. productivity growth and value added. We explore how the measurement of productivity and value added in manufacturing has been affected by the dramatic rise in imports of manufactured goods, which more than doubled from 1997 to 2007. We argue that, analogous to the widely discussed problem of outlet substitution bias in the literature on the Consumer Price Index, the price declines associated with the shift to low-cost foreign suppliers are generally not captured in existing price indexes. Just as the CPI fails to capture fully the lower prices for consumers due to the entry and expansion of big-box retailers like Wal-Mart, import price indexes and the intermediate input price indexes based on them do not capture the price drops associated with a shift to new low-cost suppliers in China and other developing countries. As a result, the real growth of imported inputs has been understated. And if input growth is understated, it follows that the growth in multifactor productivity and real value added in the manufacturing sector have been overstated. We estimate that average annual multifactor productivity growth in manufacturing was overstated by 0.1 to 0.2 percentage point and real value added growth by 0.2 to 0.5 percentage point from 1997 to 2007. Moreover, this bias may have accounted for a fifth to a half of the growth in real value added in manufacturing output excluding the computer and electronics industry.

We are grateful for Mike Harper's assistance with the analysis of the productivity measurement implications. We draw heavily upon Alterman, Diewert and Feenstra (1999), and the authors are indebted to Bill Alterman and Erwin Diewert for that earlier study which we apply here to U.S. productivity growth. For helpful comments we thank seminar participants at Columbia, Harvard, Oxford, and the NBER. For financial support Feenstra and Slaughter thank the National Science Foundation. Finally, the views expressed in this paper are those of the authors, not those of the Bureau of Economic Analysis, and should not be interpreted as reflecting the views of the Board of Governors of the Federal Reserve System or of any other person associated with the Federal Reserve System. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.© 2009 by Robert C. Feenstra, Benjamin R. Mandel, Marshall B. Reinsdorf, and Matthew J. Slaughter. All rights reserved. Short sections of text, not to exceed two paragraphs, may be quoted without explicit permission provided that full credit, including © notice, is given to the source. ABSTRACTSince 1995, growth in productivity in the United States appears to have accelerated dramatically. In this paper, we argue that part of this apparent speed-up actually represents gains in the terms of trade and tariff reductions, especially for information-technology products. We demonstrate how unmeasured gains in the terms of trade and declines in tariffs can cause conventionally measured growth in real output and productivity to be overstated. Building on the GDP function approach of Diewert and Morrison, we develop methods for measuring these effects. From 1995 through 2006, the average growth rates of our alternative price indexes for U.S. imports are 1.5% per year lower than the growth rate of price indexes calculated using official methods. Thus properly measured terms-of-trade gain can account for close to 0.2 percentage points per year, or about 20%, of the 1995-2006 apparent increase in productivity growth for the U.S. economy. Bias in the price indexes used to deflate domestic output is a question beyond the scope of this paper, but if upward bias were also present in those indexes, this could offset some of the effects of mismeasurement of gains in terms of trade.

A key emerging insight in international economics is that the scope for quality differentiation can help to explain patterns in export prices at the level of products or firms. In this paper, a unified theoretical framework of firm heterogeneity in cost and quality is brought to bear on an expansive data set of U.S. import transaction prices collected by the Bureau of Labor Statistics (BLS). The higher moments of the price distribution are used to identify the scope for quality differentiation at the detailed product level; highly differentiated products account for about half of U.S. import value. The product classification is then used to evaluate two claims in the nascent firm-level trade quality literature. First, the positive link between exporter capability and price is found to depend on the nature of the product: productive exporters simultaneously specialize in high-priced varieties in quality differentiated goods and low-priced varieties in more homogeneous goods. Second, a novel time series test documents firm sorting into export markets according to output quality.