Search results for "LAB"

Comparing past and present wage inequality in two globalisation periods

2013

Abstract This paper compares past and present globalisation with an aim to highlighting the different factors that drove wage inequality then and those which are doing so now. We have constructed a ratio of wage inequality for 15 countries in the first period of globalisation (1870–1913) and the subsequent period of deglobalisation (1914–1930) and then compare this pattern to wage inequality in the 1980s and 1990s. We propose that the difference in wage inequality trends for the two globalisation periods is due to migration and institutional factors (education and labour market institutions). These factors offset the increase in wage inequality produced by globalisation and technological ch…

Plant Productivity Dispersion and the College Premium: Evidence from the United States 1977-1997

2015

For the United States in 1987-2014, I document at business cycle frequencies that the high-skill workers’ employer size wage premium is high (low) in times of low (high) unemployment relative to that of the low-skill workers. Specifically, the differential employer size wage premium between high-skill and low-skill workers has an unconditional correlation of -0.4 with the unemployment rate, and varies by about 6 percent over the business cycle. The skill premium itself does not exhibit a clear business cycle pattern over the sample period.

Technology Diffusion, Worker Mobility and the Returns to Skill

2015

In this paper I illustrate how the diffusion across firms of a skill-neutral technology leads to a skill-biased impact on the economy. The model identifies (i) differences in inter-firm mobility between skill groups, (ii) productivity dispersion across firms within industries, and (iii) differences in wages between small and large firms as key determinants of the skill premium. Calibrated to match differences in inter-firm mobility between skill groups and rising productivity dispersion across firms, the model ascribes one-third of the sharp increase in the skill premium in U.S. manufacturing from 1977 to 1997 to skill-neutral technical progress and the technology diffusion process itself. …

Globalization, Worker Mobility and Wage Inequality

2015

In the present paper, I integrate frictional labor markets with on-the-job search into an otherwise standard heterogeneous firm model of intra-industry trade. Most importantly, I show that the returns to workers’ inter-firm mobility are higher in a trade equilibrium than in autarky. Intuitively, by favoring large and productive firms, international trade amplifies the disparities in profitability between small and large firms. Hence, the returns to labor reallocation across firms rise. In view of the empirically observed higher inter-firm mobility among high-skill workers, this suggests a skill-biased impact of trade liberalization.

Small Employers, Large Employers and the Skill Premium

2015

I document the comovement of the skill premium with the differential employer size wage premium between high- and low-skill workers in U.S. manufacturing during the postwar era. For the baseline specification, i.e., establishments with at least 500 employees categorized as large employers and non-production workers as high-skilled, I obtain a correlation coefficient of 0.87. Exploiting variations across subindustries while controlling for other potentially relevant factors, I estimate that an increase by ten log-points in the differential size premium is associated with an increase in the skill premium by three log-points.

Turbulent Flow Structures For Different Roughness Conditions of Channel Walls: Results of experimental investigation in laboratory flumes

2013

The warping torsion as a sequence of infinite bending problems

2014

[EN] In the present article, a methodology for teaching modeling problem of mixed torsion for thin-walled open sections. The mathematical analogy of warped twist as a problem of Euler-Bernoulli beams is exploited. In fact, the paper proposes to represent the warped torsion differential equation as a perturbation of the pure torsion or also called the Saint-Venant theory. Thus, it is demonstrated that under certain conditions related to the value of the torsional slenderness the response of a beam is the addition of infinite pure warped problems, that is, infinite bending problems, according to the analogy. We call this the asymptotic torsion analogy.

Effect of pH and nitrite concentration on nitrite oxidation rate

2011

The effect of pH and nitrite concentration on the activity of the nitrite oxidizing bacteria (NOB) in an activated sludge reactor has been determined by means of laboratory batch experiments based on respirometric techniques. The bacterial activity was measured at different pH and at different total nitrite concentrations (TNO 2). The experimental results showed that the nitrite oxidation rate (NOR) depends on the TNO 2 concentration independently of the free nitrous acid (FNA) concentration, so FNA cannot be considered as the real substrate for NOB. NOB were strongly affected by low pH values (no activity was detected at pH 6.5) but no inhibition was observed at high pH values (activity wa…

Characterisation and Anaerobic Batch Degradation of Materials Accumulating in Anaerobic Digesters Treating Poultry Slaughterhouse Waste

2001

We characterised materials accumulating in two failed mesophilic semi-continuous anaerobic digesters treating poultry slaughterhouse waste and, for reference, materials in the two well-performing digesters, to find the anaerobic degradability of these materials and the factors affecting their degradation. We also studied materials accumulating and stratifying in various layers in one of the two well-performing digesters. The material from the most severely failed digesters produced methane sluggishly and did not improve appreciably even with 33 percent dilution suggesting that the recovery of failed process is slow. The methane production was apparently affected by the accumulated long-chai…

The significance of soils and soil science towards realization of the United Nations Sustainable Development Goals

2016

Abstract. In this forum paper we discuss how soil scientists can help to reach the recently adopted UN Sustainable Development Goals (SDGs) in the most effective manner. Soil science, as a land-related discipline, has important links to several of the SDGs, which are demonstrated through the functions of soils and the ecosystem services that are linked to those functions (see graphical abstract in the Supplement). We explore and discuss how soil scientists can rise to the challenge both internally, in terms of our procedures and practices, and externally, in terms of our relations with colleague scientists in other disciplines, diverse groups of stakeholders and the policy arena. To meet th…