SKILL POLARIZATION IN LOCAL LABOR MARKETS UNDER SHARE‐ALTERING TECHNICAL CHANGE

This paper considers the “share‐altering” technical change hypothesis in a spatial general equilibrium model where individuals have different levels of skills. Building on a simple Cobb‐Douglas production function, our model shows that the implementation of skill‐biased technologies requires a sufficient proportion of highly educated individuals. Moreover, when technical progress disproportionately replaces middle‐skill jobs, the local distribution of skills will exhibit “fat‐tails,” where the proportion of both highly skilled and low‐skilled workers increases. These and several other predictions of the model are consistent with recent existing evidence, and avoid some major criticism against the “canonical” CES framework.     

NEARCHOS. Networked Archaeological Open Science: Advances in Archaeology Through Field Analytics and Scientific Community Sharing

The full release and circulation of excavation results often takes decades, thus slowing down progress in archaeology to a degree not in keeping with other scientific fields. The nonconformity of released data for digital processing also requires vast and costly data input and adaptation. Archaeology should face the cognitive challenges posed by digital environments, changing in scope and rhythm. We advocate the adoption of a synergy between recording techniques, field analytics, and a collaborative approach to create a new epistemological perspective, one in which research questions are constantly redefined through real-time, collaborative analysis of data as they are collected and/or searched for in an excavation. Since new questions are defined in science discourse after previous results have been disseminated and discussed within the scientific community, sharing evidence in remote with colleagues, both in the process of field collection and subsequent study, will be a key innovative feature, allowing a complex and real-time distant interaction with the scholarly community and leading to more rapid improvements in research agendas and queries.     

A Cost-Based Ripley’s <Emphasis Type="Italic">K</Emphasis> Function to Assess Social Strategies in Settlement Patterning

Most quantitative approaches to distributional analysis in archaeology assume a homogeneous study surface that is amenable to easy generalisations. This framework has been widely used to describe settlement processes, disregarding the spatial heterogeneity inherent to geographic reality. In other words, researchers have often assumed that the correlation between the elements of a spatial distribution is a function of the Euclidean distance (i.e. straight line distance) between them. Other archaeological studies have tested alternative measures to Euclidean distances, such as cost-based ones, both to describe optimal routes and to assess spatial autocorrelation in a point pattern. Nevertheless, until now there has been no suitable model to introduce these measures into spatial statistical equations. In order to overcome this obstacle, we approach the implementation problem inversely by embedding the spatial pattern under study into a Euclidean frame of reference based on its cost-distance pairwise matrix. This paper describes the application of this methodology on one of the main tools used by archaeologists to assess settlement patterns: Ripley’s K function. We present two case studies, covering both macroscale and mesoscale, with significant variations in the results depending on the use of the Euclidean or cost-based approach. Data, functions and results have been R-packaged for the sake of reproducibility and reusability, allowing other researchers to build upon our methods.     

Characterization of concrete from Roman buildings for public spectacles in <Emphasis Type="Italic">Emerita Augusta</Emphasis> (Mérida,Spain)

The aim of this work is to characterize the original concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required for a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (optical polarized microscopy and X-ray diffraction) and petrophysical (bulk and real density, open porosity to water and Hg, mechanical strength and ultrasonic velocity) analyses. With this work, it is possible to fill the gap that exists in this field and the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The results allowed us to determine the composition of the Roman concrete and to infer the provenance of the aggregates used in these monuments.     

THE EFFECT OF ACCESSIBILITY ON PRODUCTIVITY IN SPANISH MANUFACTURING FIRMS

This paper evaluates the impact of accessibility on the productivity of Spanish manufacturing firms. We suggest the use of accessibility indicators of workers and commodities, integrating transport, land use, and individual components, computing real distances or traveling times using the Spanish full road network. Estimated firms’ total factor productivity is explained as a function of the accessibility indicators and additional control variables. Results evidence the crucial role on firms’ productivity to the accessibility of commodities and to a slightly lesser extent the workers.     

A gender analysis of everyday mobility in urban and rural territories: from challenges to sustainability

Gender differences in mobility patterns between women and men have long been acknowledged. This study analyses how these differences are reproduced in different urban and rural contexts. Using mobility data from a large travel survey taken in 2006 in Spain, we examine the differences between gender mobility through age, modal split and trip purposes. Special attention is paid to how territory shapes mobility and how these territorial settings differently affect gendered mobilities. The use of this data source allows the comparison of all trips made by the total population, including all means of transport. By taking a global view on mobility, the uneven relationships that men and women have with different means of transport become more visible. After disaggregating data by age and territorial settings, results show that women are using sustainable transport modes more often than men, and travelling for more diverse reasons. Gender is thus a fundamental variable in understanding modal split and, by extension, transport sustainability, in terms of energy consumption and the emission of greenhouse gases. From this point of view, we consider women's mobility knowledge and practices – typically related to the most sustainable means of transport – as factors with rising value that could effectively guide public policy in its way to promote more sustainable mobility patterns.     

Evolution of the Territorial Coverage of the Railway Network and its Influence on Population Growth: The Case of England and Wales, 1871–1931

Abstract

The introduction of the railway network brought with it an unprecedented improvement in accessibility. In this work, the authors analyze the evolution of the territorial coverage of the railway network and its influence on the uneven distribution of population. To carry out this research, they used comparable data on total population obtained from census records relating to civil parishes of England and Wales, taken at 10-year intervals from 1871. The hypothesis that they wished to test was that good access to a railway station was related to significant increases in population. This exercise provides a better understanding of regional variations in population growth and allows the authors to identify current differences between urban and rural areas that have resulted from their historical evolution.     

Five thousand years of atmospheric Ni,Zn, As,and Cd deposition recorded in bogs from NW Iberia: prehistoric and historic anthropogenic contributions

The analysis of environmental archives from across the world has demonstrated that human perturbation of the geochemical cycles of trace metals and the resultant atmospheric metal contamination date back, at least, several millennia. However, an understanding of the local processes and timing of changes in trace metal deposition is also essential for a proper global interpretation. The Iberian Peninsula was a major mining area since prehistoric times and the analysis of environmental archives provides a good opportunity to improve our understanding of the history of mining and metallurgy in Europe. We present the results from three ¹⁴C dated peat cores from the Xistral Mountains (NW Iberia). These records are used to reconstruct past atmospheric deposition of Ni, Zn, As, and Cd. The chronology of the changes in concentrations and metal accumulation rates was found to be concordant in the three bogs, and showed great similarity to total Pb, Hg, and Pb isotope ratios as determined in previous investigations. They present a consistent view of changes in atmospheric pollution and the importance of metals in the development of human societies, especially: i) the first evidence of atmospheric metal pollution 3400 years ago, which is simultaneous with the expansion of the Atlantic Bronze Koine; ii) a pollution event between 2350 and 2150 years ago, associated to the development of so-called Celtic culture (local Late Iron Age); iii) a dramatic increase of metal fluxes in Roman times; iv) a severe and rapid increase in the last 250 years corresponding to the beginning of the industrial revolution in Europe, reflecting the emergence of the new dominant sources of pollution, and v) the increase of long range atmospheric transport of pollutants. Our data suggest that all detected ancient (until ca. 1450 cal BP) periods of enhanced Ni, Zn, As, and Cd accumulation may have had an anthropogenic origin, related to the onset and development of mining and metallurgy.