Common and idiosyncratic shocks to labor productivity across sectors and countries: Is climate relevant?

We use two methodologies, the least square dummy variables approach and the dynamic factor models, to decompose the labor productivity growth rate for a large sample of countries into common, i.e. global, and idiosyncratic, i.e. country, components. We find that country specific effects are much more important than common effects in explaining labor productivity. The interesting result is that, when splitting the sample of countries into those located in temperate zones and those located in tropical zones, we find that the common component plays a larger role in temperate countries. Thus, given the wide gap in labor productivity between the two climatic zones, policy should be targeted on developing technologies for tropical zones and/or on helping them to absorb R&D targeted for temperate countriesLabor productivity, Decomposition, Dynamic factors, Panel unit roots.

International R&D Spillovers and Productivity Growth in the Agricultural Sector A Panel Cointegration Approach

This paper analyses, within the new growth theory framework and using panel cointegration techniques, the effect of agricultural international technological spillovers on total factor productivity growth for a sample of 47 countries during the period 1970-1992. The analysis shows that total factor productivity is strongly influenced by domestic as well as foreign public R&D spending in agricultural sector and geographical factors matters. Countries located in temperate zones benefit more than countries located in tropical zones from technological spillovers. Finally, the analysis shows that the rate of return to agricultural R&D spending is higher in tropical countries and this could justify new support and an even greater investment of funds for agricultural R&D for these countries.Technology spillover, agricultural productivity, panel cointegration, Research and Development/Tech Change/Emerging Technologies, C14, O30, Q16,

Tropical Underdevelopment

Most recent cross-country analyses of economic growth have neglected the importance of physical geography. This paper reviews the distinctive development challenges faced by economies situated in tropical climates. Using geographic information system (GIS) mapping, the paper presents evidence that production technology in the tropics has lagged behind temperate zone technology in the two critical areas of agriculture and health, and this in turn opened a substantial income gap between climate zones. The difficulty of mobilizing energy resources in tropical economies is emphasized as another significant contributor to the income gap. These factors have been amplified by geopolitical power imbalances and by the difficulty of applying temperate-zone technological advances in the tropical setting. The income gap has also been amplified because poor public health and weak agricultural technology in the tropics have combined to slow the demographic transition from high fertility and mortality rates to low fertility and mortality rates. The analysis suggests that economic development in tropical ecozones would benefit from a concerted international effort to develop health and agricultural technologies specific to the needs of the tropical economies.

Phylogeography of Japanese encephalitis virus:genotype is associated with climate

The circulation of vector-borne zoonotic viruses is largely determined by the overlap in the geographical distributions of virus-competent vectors and reservoir hosts. What is less clear are the factors influencing the distribution of virus-specific lineages. Japanese encephalitis virus (JEV) is the most important etiologic agent of epidemic encephalitis worldwide, and is primarily maintained between vertebrate reservoir hosts (avian and swine) and culicine mosquitoes. There are five genotypes of JEV: GI-V. In recent years, GI has displaced GIII as the dominant JEV genotype and GV has re-emerged after almost 60 years of undetected virus circulation. JEV is found throughout most of Asia, extending from maritime Siberia in the north to Australia in the south, and as far as Pakistan to the west and Saipan to the east. Transmission of JEV in temperate zones is epidemic with the majority of cases occurring in summer months, while transmission in tropical zones is endemic and occurs year-round at lower rates. To test the hypothesis that viruses circulating in these two geographical zones are genetically distinct, we applied Bayesian phylogeographic, categorical data analysis and phylogeny-trait association test techniques to the largest JEV dataset compiled to date, representing the envelope (E) gene of 487 isolates collected from 12 countries over 75 years. We demonstrated that GIII and the recently emerged GI-b are temperate genotypes likely maintained year-round in northern latitudes, while GI-a and GII are tropical genotypes likely maintained primarily through mosquito-avian and mosquito-swine transmission cycles. This study represents a new paradigm directly linking viral molecular evolution and climate

WetNet: Using SSM/I data interactively for global distribution of rainfall and precipitable water

By completing hardware installation, preparing for comparative studies of SSM/I, radar, and lightning data, it is believed that this will be a powerful combination for evaluating the global distribution of tropical rainfall, and the vertical distribution of latent heating, with strong application to algorithms for use on TRMM, EOS-A, and future GOES spacecraft. Potential data bases will be surveyed, about 5 case studies with surface rainfall, radar, lightning, and sounding data will be identified. SSM/I algorithms will be used to identify convective regions of MCSs. A catalog will be developed of the global profile of heavy tropical rainfall, and how these zones are organized within larger tropical weather systems. Beginning with the first few months of SSM/I data distributed over WetNet, SSM/I radiances will be compared with TOVS radiance (moisture and thermal) and OLR observations. The purpose is to improve understanding of how real world water vapor profiles in the tropical atmosphere are perceived by SSM/I precipitable water algorithm and, at the same time, by the TOVS water vapor channel

Stratospheric Ozone Trends over the Tropics

The study of the variability and seasonality of ozone over the tropics was carried out between the regions spreading from Latitude 300 South to 300 North. The region was divided into twelve zones of 50 latitudes each, that is, Latitude 0-50 South, 0-50 North,5– 100South and 5– 100 North etc. Secondary data from satellite for each zone was studied both individually and collectively for the period of 1997 to 1999. The results of the statistical analysis indicated that there was seasonality in time of occurrence of maximum and minimum ozone concentration in the tropics. In the northern zones where Nigeria fell, the period of maximum concentration appeared to conincide with the raining season while the minimum with the dry season. The variability of ozone was found to be higher in the high tropical latitudes than around the equato

Scientific results of the Bryotrop expedition to Zaire and Rwanda : 7., life strategies of epiphytic bryophytes from tropical lowland and montane forests, ericaceous woodlands and the Dendrosenecio subpáramo of the eastern Congo basin and the adjacent mountains (Parc National de Kahuzi-Biega/Zaire, Forêt de Nyungwe/Rwanda)

Life strategies of epiphytic bryophytes are studied along an altitudinal gradient from the eastern Congo basin (tropical lowland zone) to the mountains of the East-African graben (tropical subalpine/alpine Zone; BRYOTROP III-transect). Three strategies, Colonists, Perennial shuttle species and Perennial stayers can be observed, which are further subdivided according to their reproduction tactic (high sexual reproductive effort, high asexual reproductive effort, moderately or low sexual and asexual reproductive effort). Of these, only taxa with a long life span (perennials) are of importance, indicating the unchanging and constant ecological conditions and long-lasting microsites, provided by the epiphytic habitats. The basis for the life strategy pattern analysis along the altitudinal gradient were plant sociological investigations and the determination of the mean percentage cover values for the different life strategy categories. By this, the distribution and occurrence of the different strategies within the communities and the altitudinal zones can be shown

Chemical and mineralogical heterogeneities of weathered igneous profiles: implications for landslide investigations

International audienceLandslides in tropical and sub-tropical regions are generally associated with weathered rock profiles which often possess chemical and mineralogical heterogeneities at material- and mineral-scales. Such heterogeneities reach a climax by the occurrences of oxyhydroxide- and clay-rich zones. Weakness and low permeability of these zones makes them ideal for the development of slip zones along which landslides take place. This paper describes the nature and distribution of chemical and mineralogical heterogeneities within weathered profiles developed from felsic igneous rocks in Hong Kong. It sets out the use of integrated geochemical and mineralogical studies to improve understanding of the development of critical heterogeneities and hence to predict their types and presence in a given weathered profile

Observed Tightening of Tropical Ascent in Recent Decades and Linkage to Regional Precipitation Changes

Climate models predict that the tropical ascending region should tighten under global warming, but observational quantification of the tightening rate is limited. Here we show that the observed spatial extent of the relatively moist, rainy and cloudy regions in the tropics associated with large‐scale ascent has been decreasing at a rate of −1%/decade (−5%/K) from 1979 to 2016, resulting from combined effects of interdecadal variability and anthropogenic forcings, with the former contributing more than the latter. The tightening of tropical ascent is associated with an increase in the occurrence frequency of extremely strong ascent, leading to an increase in the average precipitation rate in the top 1% of monthly rainfall in the tropics. At the margins of the convective zones such as the Southeast Amazonia region, the contraction of large‐scale ascent is related to a long‐term drying trend about −3.2%/decade in the past 38 years