Developing country growth collapse revisited: demographic influences and regional differences

This paper bridges two related, but up to now, unconnected literatures: economic growth stability and population-economic growth. The paper is different from previous population-economic growth analyses by focusing on instability of economic growth in developing countries. This study contributes to a previous paper on the developing country growth collapse by adding important demographic variables. The paper provides an explanation for “new” negative correlations of population and economic growth: because 1960s were a relatively smooth time for economic growth, youth dependency did not seem important; however, during turbulent 1970s and 1980s, countries with falling dependency burdens weathered economic shocks better.demographic transition, developing countries, economic growth, population growth

Consumption-Driven Environmental Impact and Age Structure Change in OECD Countries

This paper examines two environmental impacts for which population has a substantial demonstrated influence: transport carbon emissions and residential electricity consumption. It takes as its starting point the STIRPAT framework and disaggregates population into four key age groups: 20-34, 35-49, 50-69, and 70 and older. Population age structure’s influence was significant and varied across cohorts, and its profile was different for two dependent variables. For transport, young adults (20-34) were intensive, whereas the other cohorts had negative coefficients. For residential electricity consumption, age structure had a U-shaped impact: the youngest and oldest had positive coefficients, while the middle cohorts had negative coefficients.demography, environment, FMOLS panel cointegration, GHG emissions projections, IPAT, STIRPAT

Breaks and Trends in OECD Countries’ Energy-GDP Ratios

This paper uses the econometrics of endogenous structural breaks to examine changes in energy intensity for OECD countries over 1960-2009. Nearly all OECD countries currently have significant negatively trending energy-GDP ratios; but for several countries those negative trends are recent, and two countries have recent significant positive trends. For several countries, energy intensity had a significant positive trend followed by a break and then a significant negative trend. Those break-dates, however, appear to have little to do with level of development (GDP per capita). Instead, among the likely causes of break timing are the volatile energy prices of the 1970s and early 1980s and the increased concern for the environment in the late 1960s and early 1970s. These findings have implications for future modeling of energy consumption as well as for the role of energy price policy in developed and developing countries.energy intensity, endogenous structural breaks, modeling environment and development, Resource /Energy Economics and Policy, Q43, O13,

Demographic dynamics and per capita environmental impact: using panel regressions and household decompositions to examine population and transport

Demographic variables have tended to be ignored in many environment-development analyses. This paper examines how population changes (in aging, households, and urbanization/density) can help explain changes/differences in personal transport using both macro- and micro- level data. First, panel regressions are performed with IEA-OECD road sector energy use data (spanning 1960-2000) on spatial population measures, average household size, and age structure data. Then US household data is used to determine the extent compositional changes in the nature of households can explain changes in per capita driving. An Environmental Kuznets Curve for per capita road energy use was rejected—the coefficients on the GDP squared terms were insignificant and the implied turning points were well outside the sample range; instead, the relationship between wealth and road energy was found to be monotonic (log-linear). The ideas that more densely populated countries have less personal transport demands, the young drive more, and smaller households mean higher per capita driving were confirmed. The basic result from the household decompositions was that changes in demand were more important than compositional changes, however, during some periods the compositional change component was considerable. A few policy implications can be drawn from these analyses. First, the look at micro data implies that there is much potential for policy to affect transport behavior since the compositional component of change—more difficult for policy to alter—is smaller than the behavioral or demand component. However, the look at the macro data implies that spatial factors, like population density and urbanization—which also can be difficult to alter—are significant in influencing personal transport demand.OECD countries, energy consumption, environmental policy, household size, transport

Solar energy trap

An apparatus is described for trapping solar energy for heating a fluid that could be subsequently used in turbines and similar devices. The apparatus includes an elongated vertical light pipe having an open end through which the visible spectrum of electromagnetic radiation from the sun passes to strike a tubular absorber. The light pipe has a coated interior surface of a low absorptivity and a high reflectivity at the visible wavelengths and a high absorptivity/emissivity ratio at infrared wavelengths. The tubular absorber has a coating on the surface for absorbing visible wavelengths to heat the fluid passing through. Infrared wave lengths are radiated from the tubular absorber back into the light pipe for heating fluid passing through a tubular coil wound around it

Large-scale solar thermal collector concepts

Thermal collector could be used ultimately to power steamplant to produce electricity. Collector would consist of two major subsystems: (1) series of segmented tracking mirrors with two axes of rotation and (2) absorber mounted on centrally located tower

Laser power transmission for space power and propulsion

An early status report is presented for a review being made of the state of development of major components and subsystems required for ground-to-space, space-to-space, or space-to-ground laser power transmission for electric or thermal power or propulsion. System characteristics are being evaluated from an applications viewpoint, and major problem areas are being identified. The object is to identify a rewarding first application of lasers for space power and propulsion. An evolution of laser power transmission capabilities over the next 20 years is projected. Supporting technology requirements are to be identified, priorities set, and continued developments coordinated with other government agencies

Structures and Materials Working Group report

The appropriateness of the selection of four issues (advanced materials development, analysis/design methods, tests of large flexible structures, and structural concepts) was evaluated. A cross-check of the issues and their relationship to the technology drivers is presented. Although all of the issues addressed numerous drivers, the advanced materials development issue impacts six out of the seven drivers and is considered to be the most crucial. The advanced materials technology development and the advanced design/analysis methods development were determined to be enabling technologies with the testing issues and development of structural concepts considered to be of great importance, although not enabling technologies. In addition, and of more general interest and criticality, the need for a Government/Industry commitment which does not now exist, was established. This commitment would call for the establishment of the required infrastructure to facilitate the development of the capabilities highlighted through the availability of resources and testbed facilities, including a national testbed in space to be in place in ten years

LDAExplore: Visualizing Topic Models Generated Using Latent Dirichlet Allocation

We present LDAExplore, a tool to visualize topic distributions in a given document corpus that are generated using Topic Modeling methods. Latent Dirichlet Allocation (LDA) is one of the basic methods that is predominantly used to generate topics. One of the problems with methods like LDA is that users who apply them may not understand the topics that are generated. Also, users may find it difficult to search correlated topics and correlated documents. LDAExplore, tries to alleviate these problems by visualizing topic and word distributions generated from the document corpus and allowing the user to interact with them. The system is designed for users, who have minimal knowledge of LDA or Topic Modelling methods. To evaluate our design, we run a pilot study which uses the abstracts of 322 Information Visualization papers, where every abstract is considered a document. The topics generated are then explored by users. The results show that users are able to find correlated documents and group them based on topics that are similar