International comparison of sectoral energy- and labour-productivity performance; stylised facts and decomposition of trends

This paper simultaneously explores trends in energy- and labour productivity for 14 OECD countries and 13 sectors over the period 1970-1997. A principal aim of this paper is to trace back macroeconomic productivity developments to developments at the level of individual sectors, in order to correct trends in technology-driven productivity improvements for the impact of structural effects. First, we document trends in macroeconomic energy- and labour productivity performance, examining the role of the Manufacturing, Services, Transport and Agricultural sector. Second, we take a closer look at the role of 10 Manufacturing sectors in driving aggregate Manufacturing energy- and labour-productivity performance. A cross-country decomposition analysis reveals that in some countries structural changes contributed considerably to aggregate energy-productivity growth while in other countries they partly offset energy-efficiency improvements. In contrast, structural changes only play a minor role in explaining aggregate labour-productivity developments. We identify for each country the percentage contribution of each sector to aggregate structural and efficiency changes. Furthermore, we find labour productivity growth to be higher on average than energy productivity growth. Over time, this bias towards labour productivity growth is increasing in the Transport, Agriculture and aggregate Manufacturing sectors, while it is decreasing in Services and most Manufacturing sectors.

Dutch Sectoral Energy Intensity Developments in International Perspective, 1987–2005

This paper makes use of a new dataset to investigate energy intensity developments in the Netherlands over the period 1987–2005, in comparison with 18 other OECD countries. A key feature of our analysis is that we combine this cross-country perspective with a high level of sector detail, covering 51 sectors. Particularly innovative is our evaluation of energy intensity developments in a wide range of Service sectors. We find that between 1987 and 2005 energy intensity in the Netherlands decreased on average with 0.9% points per year at the aggregate economy level and with 0.2% points at the aggregate manufacturing sector level, whereas it increased with 0.4% points at the aggregate Service sector level. This performance is considerably below the OECD average, and has been especially poor between 1987 and 1995. In terms of energy intensity levels, performance of the Netherlands is close to the OECD average at the aggregate economy level and in Manufacturing. In Services, the energy intensity level in the Netherlands was about 50% lower than the OECD average in 1987, but this lead has almost disappeared by 2005. Finally, we find that in the Manufacturing sector, between 1987 and 2005, about half of the energy efficiency improvements were undone by a shift towards a more energy-intensive industry structure, most notably through growth of the Chemical sector. In the Service sector, on the contrary, shifts in the underlying sector structure helped in slowing down energy intensity increase by about one-third between 1987 and 2005. �

Sectoral energy- and labour-productivity convergence

This paper provides an empirical analysis of convergence patterns for energy- and labour-productivity developments at a detailed sectoral level for 14 OECD countries, covering the period 1970-1997. Cross-country differences of energy-productivity levels are shown to be substantially larger than cross-country differences of labour-productivity levels at all levels of sectoral aggregation. A s-convergence analysis shows that the development of cross-country variation in productivity performance depends on the level of aggregation. Both patterns of international productivity convergence and divergence exist across sectors. Using a panel-data approach, we find in most sectors energy productivity to grow relatively fast in countries with relatively low initial productivity levels, while in several sectors this is also true for labour productivity. This evidence of ß-convergence supports the hypothesis that lagging countries tend to catch up with technological leaders, in particular in terms of energy productivity. Moreover, the results show that convergence is conditional rather than unconditional, meaning that productivity levels converge to country-specific steady states. Searching for the fundamentals determining cross-country productivity differentials reveals a positive productivity effect of energy prices and economies of scale in several sectors, while wages, investment share, openness and specialisation play only a very limited role in explaining (cross-country differences in) energy- and labour-productivity growth.

Sectoral Energy- and Labour-Productivity Convergence

This paper provides an empirical analysis of energy- and labour-productivity convergence at a detailed sectoral level for 14 OECD countries, covering the period 1970-1997. A -convergence analysis shows that the development of cross-country variation in productivity performance depends on the level of aggregation. Both patterns of convergence as well as divergence are found. A -convergence analysis provides support for the hypothesis that in most sectors lagging countries tend to catch up with technological leaders, in particular in terms of energy productivity. Moreover, the results show that convergence is conditional rather than unconditional, meaning that productivity levels converge to country-specific steady states, and that cross-country differences of energy-productivity levels are substantially larger than of labour-productivity levels at all levels of sectoral aggregation. Finally, searching for the fundamentals determining cross-country productivity differentials reveals a positive productivity effect of energy prices and economies of scale in several sectors, while wages, investment share, openness and specialization play only a very limited role in explaining (cross-country differences in) energy- and labour-productivity growth. Keywords: energy productivity, labour productivity, convergence, sectoral analysis JEL codes: O13, O47, O5, Q43

Energy-intensity developments for 19 OECD countries and 51 sectors

This paper presents stylized facts on energy-intensity developments for 19 OECD countries and 51 sectors over the period 1980âËâ2005. A principal aim of this paper is to introduce and discuss a new database that combines the recently launched ‘EU KLEMS Growth and Productivity Accounts’ with physical-energy data from the International Energy Agency (IEA). We do so by means of an empirical analysis consisting of the following components at various levels of sectoral detail. First, we document per country the growth rates of energy use, value added and energy intensity (i.e. the ratio of energy use to value added). Second, we compare levels of energy intensity across countries and analyze the evolution of the observed cross-country differences over time. Third, by means of a decomposition analysis we calculate for each country to what extent aggregate energy-intensity trends can be explained from, respectively, shifts in the underlying sectoral structure and efficiency improvements within individual sectors. Finally, we identify issues and areas of research within the field of energy economics where these data may be applied fruitfully.

Structural Change and Convergence of Energy Intensity across OECD Countries, 1970-2005

This paper uses a new dataset derived from a consistent framework of national accounts to compute and evaluate energy intensity developments across 18 OECD countries and 50 sectors over the period 1970-2005. We find that across countries energy intensity levels tend to increase in a fairly wide range of Services subsectors, but decrease in most Manufacturing sectors. A decomposition analysis reveals that changes in the sectoral composition of the economy explain a considerable and increasing part of aggregate energy intensity dynamics. A convergence analysis reveals that only after 1995 cross-country variation in aggregate energy intensity levels clearly tends to decrease, driven by a strong and robust trend break in Manufacturing and enhanced convergence in Services. Moreover, we find evidence for the hypothesis that across sectors lagging countries are catching-up with leading countries, with rates of convergence on average being higher in Services than in Manufacturing. Aggregate convergence patterns are almost exclusively caused by convergence of within-sector energy intensity levels, and not by convergence of the sectoral composition of economies

Experimental investigation of negatively buoyant sediment plumes resulting from Dredging operations

In a first step to investigate the behaviour of sediment plumes released from dredging vessels, an experimental facility has been built to release scaled fine sediment plumes in the presence of cross flow. High-frequency measurements of velocity components and sediment concentration are obtained using acoustic and optical backscatter instruments. The paths of the axis of the experimental buoyant plumes in cross-flow have been compared to integral laws by Fisher et al. (1979), showing relatively good agreement for plumes not influenced by the dredger’s hull. Plumes with low relative density difference and high crossflow to outflow velocity ratio deviate from the integral laws due to additional mixing induced by the hull boundary layer and wake

Population Growth in American Cities between 1990 and 2010: True Contagion and Urban Hierarchy

Cities and towns are loci of population and production. In 2010, 80.7 percent of the United States population resided in urban areas, and the U.S. Bureau of Economic Analysis reported that in 2011, 90.1 percent of GDP was produced in metropolitan statistical areas (MSAs), emphasizing that urban areas and their immediate hinterlands are also centers of production. Academic interest in urban population change can be split into two literature branches. The first branch focuses on the growth and structure of individual cities. The second branch focuses on the urban system. Some of the literature in this branch implicitly assumes interconnectedness among cities, while other authors explicitly include the spatial proximity between cities or network flows among cities. However, in many studies the difference between contagious and hierarchical interrelations across cities comprised in the urban system are obfuscated. In this paper we clearly distinguish and quantify the effects of both. In other words, we focus on how the structure of the urban system influences population growth. We do this by using central place theory as a theoretical basis for addressing the research question: what natural and man-made locational characteristics influence population growth? We envisage three major contributions to the existing literature. First, we utilize a unique dataset of urban areas with decennial observations from 1990 to 2010. Most of the literature studying urban systems in the United States uses MSAs, which include rural hinterlands that are not part of the urban area, preventing a clear separation between cities and hinterlands and obscuring results. We built a new dataset at the more appropriate and precise geographic level of urban areas, which capture the agglomerated economic activity and built extent of urban locations. Second, departing from literature that includes either urban hierarchy or continuous urban proximity, our analysis includes both the hierarchical relationship among cities of differing sizes and the continuous nature of proximity to other cities. The novel use of a spatially-lagged hierarchical linear model allows us to include both these critical aspects of the urban system in our analysis. This econometric model captures the influence of the structure of the urban system on population change by allowing city-level explanatory variables to affect population growth differently, given the unique characteristics of each location's regional and central place market areas. Concurrently we account for contiguous effects through the inclusion of neighbors. Third, we include man-made amenities and characteristics of cities, which have been omitted from previous studies in an effort to avoid endogeneity in the analysis. The inclusion of these characteristics allows us to include both producer-based and consumer-based characteristics in the analysis, to capture the idea that cities are markets