Returns to Tenure or Seniority

This study documents two empirical facts using matched employer-employee data for Denmark and Portugal. First, workers who are hired last, are the first to leave the firm. Second, workers' wages rise with seniority (= a worker's tenure relative to the tenure of her colleagues). The identification problems for the wage return to tenure are shown not to apply to the return to seniority because seniority is not a deterministic function of time. Controlling for tenure, the probability of leaving the firm decreases with seniority. The increase in expected seniority with tenure explains a large part of the negative duration dependence of the hazard. Using a variety of estimation methods, we show that a 10% increase in seniority raises your wage by 0.1-0.2%, depending on the country and the method applied. Conditional on ten years of tenure, one standard deviation of seniority raises your wage by 0.5 to 1.6 percent. Forthcoming in Econometrica

What do near-term observations tell us about long-term developments in greenhouse gas emissions? A letter

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated with these systems The phenomena that determine these long-term developments (several decades or even centuries) are very different than those that operate on a shorter time-scales (a few years) Nevertheless, in the literature, we still often find direct comparisons between short-term observations and long-term developments that do not take into account the differing dynamics over these time scales In this letter, we discuss some of the differences between the factors that operate in the short term and those that operate in the long term We use long-term historical emissions trends to show that short-term observations are very poor indicators of long-term future emissions developments Based on this, we conclude that the performance of long-term scenarios should be evaluated against the appropriate, corresponding long-term variables and trends The research community may facilitate this by developing appropriate data sets and protocols that can be used to test the performance of long-term scenarios and the models that produce the

Scenarios as the basis for assessment of mitigation and adaptation

The possibilities and need for adaptation and mitigation depends on uncertain future developments with respect to socio-economic factors and the climate system. Scenarios are used to explore the impacts of different strategies under uncertainty. In this chapter, some scenarios are presented that are used in the ADAM project for this purpose. One scenario explores developments with no mitigation, and thus with high temperature increase and high reliance on adaptation (leading to 4oC increase by 2100 compared to pre-industrial levels). A second scenario explores an ambitious mitigation strategy (leading to 2oC increase by 2100 compared to pre-industrial levels). In the latter scenario, stringent mitigation strategies effectively reduces the risks of climate change, but based on uncertainties in the climate system a temperature increase of 3oC or more cannot be excluded. The analysis shows that, in many cases, adaptation and mitigation are not trade-offs but supplements. For example, the number of people exposed to increased water resource stress due to climate change can be substantially reduced in the mitigation scenario, but even then adaptation will be required for the remaining large numbers of people exposed to increased stress. Another example is sea level rise, for which adaptation is more cost-effective than mitigation, but mitigation can help reduce damages and the cost of adaptation. For agriculture, finally, only the scenario based on a combination of adaptation and mitigation is able to avoid serious climate change impacts

Genetic variant of canine distemper virus from clinical cases in vaccinated dogs in South Africa

Canine distemper virus (CDV) is a highly contagious viral pathogen of worldwide distribution that can cause lethal disease in domestic dogs and other members of the family Canidae. Genetic diversity is found among reference strains and isolates of CDV, mainly in the haemagglutinin (H) protein, and this may be associated with the increasing incidence of distemper in dogs. CDV was isolated in Vero cells expressing canine signalling lymphocyte activation molecule (Vero.DogSLAM) from peripheralblood mononuclear cells and spleen of clinically diseased, previously vaccinated South African dogs. Direct fluorescence antibody test and electronmicroscopy were used to confirm the isolation procedure. Subsequently, RT-PCR was performed on the cell culture isolates, the amplified products were purified and the complete H gene wassequenced and phylogenetically analysed. The H gene of vaccines in use in South Africa was also sequenced and comparative analyses performed. However, the sequences obtained from the sick dogs showed 100% nucleotide identity and was different to that found in virus strains used in vaccines and in isolates reported from other parts of the world in GenBank. The results suggest that a novel CDV lineage may be present in South Africa and we conclude that a recent reversion of vaccine virus to virulence was not the cause of the clinical signs seen in dogs with a previoushistory of vaccination

Antibacterial and antimycobacterial activities of South African Salvia species and isolated compounds from S. chamelaeagnea

Extracts of 16 South African Salvia species commonly used in traditional medicine to treat various microbial infections were investigated for in vitro antibacterial and antimycobacterial activities using the micro-dilution and respiratory BACTEC method, respectively. The micro-organisms tested include two Gram-positive (Staphylococcus aureus and Bacillus cereus); two Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacterial strains and the common pathogen responsible for tuberculosis, Mycobacterium tuberculosis. Extracts of the majority of species exhibited moderate to good antibacterial activity with minimum inhibitory concentration (MIC) values ranging from 0.03 to 8.00 mg/ml. Promising activity was observed against M. tuberculosis (MIC ≤ 0.50 mg/ml) with S. radula, S. verbenaca and S. dolomitica displaying the most favourable activity (MIC: 0.10 mg/ml). The antibacterial bioassay-guided fractionation of S. chamelaeagnea resulted in the isolation of four compounds: carnosol, 7-O-methylepirosmanol, oleanolic acid and its isomer ursolic acid as the active principles against S. aureus. The in vitro antibacterial and antimycobacterial activities may support the use of Salvia species in traditional medicine to treat microbial infections

Applying consumer responsibility principle in evaluating environmental load of carbon emissions

There is a need for a proper indicator in order to assess the environmental impact of international trade, therefore using the carbon footprint as an indicator can be relevant and useful. The aim of this study is to show from a methodological perspective how the carbon footprint, combined with input- output models can be used for analysing the impacts of international trade on the sustainable use of national resources in a country. The use of the input-output approach has the essential advantage of being able to track the transformation of goods through the economy. The study examines the environmental impact of consumption related to international trade, using the consumer responsibility principle. In this study the use of the carbon footprint and input-output methodology is shown on the example of the Hungarian consumption and the impact of international trade. Moving from a production- based approach in climate policy to a consumption-perspective principle and allocation, would also help to increase the efficiency of emission reduction targets and the evaluation of the ecological impacts of international trade