Innovation and Economic Growth

This paper surveys the empirical evidence on the link between innovation and economic growth. It considers a number of different measures of innovation, such as R&D spending, patenting, and innovation counts, as well as the pervasive effect of technological spillovers between firms, industries, and countries. There are three main conclusions. The first is that innovation makes a significant contribution to growth. The second is there are significant spillovers between countries, firms and industries, and to a lesser extent from government-funded research. Third, that these spillovers tend to be localized, wit foreign economies gaining significantly less from domestic innovation than other domestic firms. This suggests that although technological 'catch-up' may act to equalize productivity across countries, the process is likely to be slow and uncertain, and require substantial domestic innovation effort.

The early evolution of the solar system

The problems of relating collapse conditions in an interstellar cloud to a model of the primitive solar nebula are discussed. In such a nebula there is a radial force balance between gravity, the pressure gradient, and centrifugal forces due to the rotation. Approximate values are given for the combinations of temperature and density throughout the nebula, from a maximum of about 2000 K near the center to less than 200 K in the outer portion. These conditions are based upon the compression adiabats in the terminal stages of the collapse of an interstellar cloud. One general conclusion, of great importance for accumulation of bodies within the solar system, is that interstellar grains should not be completely evaporated at distances in the nebula beyond about one or more astronomical units

Solar models in relation to terrestrial climatic variations

The possibility is discussed of occasional larger changes in the state of the sun, lasting for some millions of years, which might be responsible for producing more drastic changes in earth's climate, called ice ages

Band Crossing and Signature Splitting in Odd Mass fp Shell Nuclei

Structure of two sets of mirror nuclei: 47V - 47Cr and 49Cr - 49Mn, as well as 49V and 51Mn, is studied using the projected shell model. Their yrast spectra are described as an interplay between the angular momentum projected states around the Fermi level which carry different intrinsic K-quantum numbers. The deviations from a regular rotational sequence are attributed to band crossing and signature splitting, which are usually discussed in heavy nuclear systems. Our results agree reasonably with experimental data, and are comparable with those from the full $pf$ shell model calculations.Comment: 3 figures, submitted to Nucl. Phys.

Conditional variances in UK regional house prices

The returns of house price indices for the 13 UK regions are modelled using time series processes, including conditional variances. The first conclusion is that the UK follows the USA, with some regions displaying time-varying variances and others with constant variances. Secondly, there is limited evidence of an asymmetric component in six of the seven regions displaying autoregressive conditional heteroskedasticity. Thirdly, the results suggest that there are three distinct housing markets in the UK, based on common structures within their mean and variance processes, and that South West England is the region driving the other time-varying variances. Variances conditionnelles dans les prix regionaux de l'immobilier au Royaume-Uni Resume Les resultats de l'indice des prix de l'immobilier pour les 13 regions du Royaume-Uni sont modelises ici au moyen de procedes de series chronologiques, y compris des variances conditionnelles. La premiere conclusion est que le Royaume-Uni suit les Etats-Unis, certaines regions presentant des variances temporelles, d'autres des variances constantes. Deuxiemement, on releve peu de traces d'un composant asymetrique dans six des sept regions presentant une heteroscedasticite conditionnelle autoregressive. Troisiemement, les resultats indiquent qu'il y aurait trois marches de l'immobilier distincts au Royaume-Uni, sur la base de structures communes dans le cadre de leurs procedes moyens et de variance, et que le sud-ouest de l'Angleterre est la region qui dynamise les autres variances temporelles. Varianzas condicionales en los precios regionales de la vivienda en el Reino Unido Extracto Las cifras de los indices de precios de la vivienda en 13 regiones del Reino Unido se modelan utilizando procesos de series temporales, incluyendo varianzas condicionales. La primera conclusion es que el Reino Unido sigue a los EE UU, con varias regiones que muestran varianzas fluctuantes con el tiempo y otras con varianzas constantes. En segundo lugar, existe evidencia limitada de un componente asimetrico en seis de las siete regiones que muestran una heteroesquedacidad condicional autorregresiva. En tercer lugar, los resultados sugieren que existen tres mercados distintivos de la vivienda en el Reino Unido, basados en estructuras comunes dentro de sus procesos de media y varianza, y que el sudoeste de Inglaterra es la region que dirige las otras varianzas fluctuantes con el tiemp