NBER Publications by Franck Portier

Gold rushes are periods of economic boom, generally associated with large increases in expenditures aimed at securing claims near new found veins of gold. An interesting aspect of gold rushes is that, from a social point of view, much of the increased activity is wasteful since it contributes simply to the expansion of the stock of money. In this paper, we explore whether business cycle fluctuations may sometimes be driven by a phenomenon akin to a gold rush. In particular, we present a model where the opening of new market opportunities causes an economic expansion by favoring competition for market share, which is essentially a dissolution of rents. We call such an episode a market rush. We construct a simple model of a market rush that can be embedded into an otherwise standard Dynami...

This paper uses aggregate Japanese data and sectoral U.S. data to explore the properties of the joint behavior of stock prices and total factor productivity (TFP) with the aim of highlighting data patterns that are useful for evaluating business cycle theories. The approach used follows that presented in Beaudry and Portier [2004b]. The main findings are that (i) in both Japan and the U.S., innovations in stock prices that are contemporaneously orthogonal to TFP precede most of the long run movements in total factor productivity and (ii) such stock prices innovations do not affect U.S. sectoral TFPs contemporaneously, but do precede TFP increases in those sectors that are driving U.S. TFP growth, namely durable goods, and among them equipment sectors.

It is often argued that changes in expectation are an important driving force of the business cycle. However, it is well known that changes in expectations cannot generate positive co-movement between consumption, investment and employment in the most standard neo-classical business cycle models. This gives rise to the question of whether changes in expectation can cause business cycle fluctuations in neo-classical setting or whether such a phenomenon is inherently related to market imperfections. This paper offers a systematic exploration of this issue. Our finding is that expectation driven business cycle fluctuation can arise in neo-classical models when one allows for a sufficient rich description of the inter-sectorial production technology, however such a structure is rarely allowed ...

In this paper we show that the joint behavior of stock prices and TFP favors a view of business cycles driven largely by a shock that does not affect productivity in the short run -- and therefore does not look like a standard technology shock -- but affects productivity with substantial delay -- and therefore does not look like a monetary shock. One structural interpretation we suggest for this shock is that it represents news about future technological opportunities which is first captured in stock prices. We show that this shock causes a boom in consumption, investment and hours worked that precede productivity growth by a few years. Moreover, we show that this shock explains about 50\% of business cycle fluctuations.