Technology usage lags

We present evidence on the differences in the intensity with which ten major technologies are used in 185 countries across the world. We do so by calculating how many years ago these technologies were used in the U.S. with the same intensity as they are used in the countries in our sample. We denote these time lags as technology usage lags and compare them with lags in real GDP per capita. We find that (i) technology usage lags are large, often comparable to lags in real GDP per capita, (ii) usage lags are highly correlated with lags in per-capita income, and (iii) usage lags are highly correlated across technologies. The productivity differentials between the state-of-the-art technologies that we consider and the ones they replace, combined with the usage lags that we document, lead us to infer that differences in the intensity of usage of technologies might account for a large part of cross-country TFP differentials. The views expressed in this paper solely reflect those of the authors and not necessarily those of the National Bureau of Economic Research, Federal Reserve Bank of San Francisco, nor those of the Federal Reserve System as a whole. This research was completed when Emilie Rovito was an economist at the Federal Reserve Bank of New York. We appreciate the financial assistance of the NSF (Grants # SES-0517910 and SBE-738101) and the C.V. Starr Center for Applied Economics. We would like to thank Mark Bils, Hitesh Makhija, Andres Rodríguez-Clare, Romain Wacziarg, and Matt Wiswall for comments and suggestions.     

Dual aspects of mantle convection through time: Changes in global upper mantle temperature,Earth’s rotation,and global plate motion acceleration induced by mantle avalanches

We use modern and novel techniques to study the problems associated with detection and analysis of multitudinous seismic events, which form the background for isolated great earthquakes. This new approach involves multivariate analysis of low and large magnitude events recorded in space over a couple of centuries in time. We propose here the deployment of the clustering scheme both for extracting small local structures and large-scale trends in synthetic data obtained from four numerically simulated models with: uniform properties (U), a Parkfield-type asperity (A), fractal brittle properties (F), and multi-size-heterogeneity fault zone (M). The mutual nearest neighbor (mnn) clustering scheme allows for extraction of multi-resolutional seismic anomalies in both the spatio-temporal and multi-dimensional feature space. We demonstrate that the large earthquakes are correlated with a certain pathway of smaller events. Visualization of the anomalies by using a recently introduced visualization package Amira reveals clearly the spatio-temporal relationships between clusters of small, medium and large earthquakes, indicating significant stress relaxation across the entire fault region. We demonstrate that this mnn scheme can extract distinct clusters of the smallest events, which precede and follow a singularly large magnitude earthquake. These clusters form larger spatio-temporal structures comprising a series of large earthquakes. The link between the large and medium magnitude events is not so clearly understood. Short-ranged correlations are dominated by strong spatio-temporal anomalies, thus reflecting the global seismic properties of the entire fault zone.     

A Comparative Study of Radio Audience Measurement Methodology

Little published research exists to guide self-regulators in their evaluation of advertising directed to children. Academic researchers have principally studied the effects of advertising upon children, rather than children's perceptions of specific commercials and ads. Research on such questions as fantasy, using famous presenters, scale disclosures and disclaimers would undoubtedly show age-related differences of perception. This might call into question the advertisers' responsibilities to the pre-school, pre-literate child. The situation is more complex when the advertiser seeks to address older children at times when younger children are also watching. Research will never satisfy the critics, but industry and self-regulators should pursue the question of how children perceive advertising.