ELEMENTS OF SKILL: TRAITS,INTELLIGENCES, EDUCATION,AND AGGLOMERATION*

ABSTRACT There are many fundamental issues in regional and urban economics that hinge on worker skills. This paper builds on psychological approaches to learning to characterize the role of education and agglomeration in the skill development process. While the standard approach of equating skill to worker education can be useful, there are important aspects of skill that are missed. Using a measure of skill derived from hedonic attribution, the paper explores the geographic distribution of worker traits, intelligences, and skills and considers the roles of urbanization and education in the skill development process.     

Agent-Based Simulation of Holocene Monsoon Precipitation Patterns and Hunter-Gatherer Population Dynamics in Semi-arid Environments

Based on archaeological evidence from Kutch-Saurashtra (N Gujarat, NW India), we use agent-based modelling (ABM) to explore the persistence of hunter-gatherer (HG) groups in semi-arid environments in the mid and late Holocene. Agents interact within a realistic semi-arid environment dominated by the monsoon. Precipitation trends are modelled from instrumental records (1871–2008) calibrated with existing models for the Asian monsoon in the Holocene (c. 12 ka–present). Experiments aim at exploring dependencies between population dynamics and climate-driven environmental change (in terms of resource availability) for precipitation patterns at the local, regional and continental scales. Resources are distributed across a simplified ground model. Average yearly precipitation (AYP, i.e. mean) and variance in yearly precipitation (VYP, i.e. standard deviation) are the main parameters affecting resource availability in the simulations. We assess the effects of environmental change on HG populations at different timescales: (1) patterns of seasonal (inter-annual) resource availability, (2) effects of changes in mean precipitation trends over the long (Pleistocene–Holocene) and the mid (Holocene, millennial) periods, and (3) effects of intra-annual precipitation variability, i.e. changes in standard deviation from mean precipitation trends over the short period (annual to decadal). Simulations show that (1) strong seasonality is coherent with the persistence of HG populations in India, independently of the geographical scale of the precipitation models, (2) changes in AYP over the mid period (Holocene) are not sufficient to explain the disappearance of HG populations in Kutch-Saurashtra (K-S) 4 ka and (3) precipitation variability (VYP) over the short period (annual to decadal) is the main parameter affecting population performance and overall ecosystem dynamics. To date, sufficiently refined palaeoclimatic records do not exist for the study area, but higher VYP values 4 ka do not exclude the possibility that other factors may have driven the disappearance of HG populations in Kutch-Saurashtra.     

Paleodiet in northern Chile through the Holocene: extremely heavy δN values in dental calculus suggest a guano-derived signature?

Dental calculus extracted from the teeth of 28 prehistoric human skeletons from coastal and valley archaeological sites in northern Chile that date from the Archaic period (∼2300 BC) to the Late Intermediate period (AD 1476) was analyzed for stable isotope (δ¹⁵N, δ¹³C) compositions. δ¹⁵N compositions were extremely heavy (+17.8 to +33.1‰), but comparable to some studies using conventional human biomaterials (hair, nail, muscle) at other prehistoric sites in northern Chile. There was a negative correlation between δ¹⁵N and δ¹³C for coastal sites, but a positive correlation for valley sites. Results for the valley sites point to a diet that was influenced by marine resources throughout all time periods. The unusually heavy δ¹⁵N values for the coastal sites require a dietary component with a δ¹⁵N composition significantly heavier than that of marine resources. The hyper-aridity at the study area (mean annual rainfall of 0.5–0.6 mm/year) is a likely contributing factor to the production of heavy δ¹⁵N values, but is unlikely to account for the heaviest δ¹⁵N values (>+30‰). One possible explanation for the heaviest δ¹⁵N values is that dietary components were impacted by isotopically-heavy guano, which is abundant in the region. Guano may have been used as a fertilizer during crop cultivation at the onset of the Formative period, continuing through the Historic period after Spanish contact. The indirect impact of guano from abundant bird habitats in the region may have influenced wild foodstuffs harvested throughout the pre-agricultural period. Results provide support for the utility of dental calculus as a proxy for obtaining stable carbon and nitrogen isotope signatures for use in paleodietary studies.     

Identification of psychoactive alkaloids in ancient Andean human hair by gas chromatography/mass spectrometry

Various ethnographic sources have demonstrated the symbolic and ritualistic importance of psychoactive plants in Native American societies. The social milieu of these mind- altering plants appears to be ancient. Archaeological evidence during the Tiwanaku empire expansion along the Atacama Desert of Chile, circa 500–1000 A.D., shows the presence of highly decorated snuffing tablets and tubes as grave goods. The preservation of mummified human bodies in the Azapa Valley, northern Chile, provided an opportunity to test the exact nature of the psychoactive plants used in this region. Using gas chromatography/mass spectrometry (GC–MS), here we show that ancient Andean populations from northern Chile consumed Banisteriopsis, a vine that contains harmine. This is the first direct archaeological evidence of hallucinogenic and medicinal ethnographic practices. Interestingly enough, this rainforest plant does not grow along the Atacama coast, thus our findings suggest extensive plant trade networks in antiquity as far as the Amazon.     

Peasants in Brazil?

Shepard Forman. The Brazilian Peasantry. New York and London: Columbia University Press, 1975. xiii + 319 pp. Tables, figures, bibliography, and references. $13.50.

*It would be difficult to claim that the experience of the Northeast can be generalized to the whole of Brazil, taking into account the different historical backgrounds and economic development of Brazilian regions.     

Land Use Patterns in Central Asia. Step 1: The Musical Chairs Model

Herding and farming coexisted in Central Asia for several thousand years as main options of preindustrial economic production. The relationship between people practicing different variants of these modes of subsistence is known to have been dynamic. Among the many possible explanations, we explore this dynamic by modeling mechanisms that connect aggregate decisions to land use patterns. Within the framework of the SimulPast project, we show here the results from step 1 of our modeling program: the Musical Chairs Model. This abstract agent-based model describes a mechanism of competition for land use between farming and herding. The aim is the exploration of how mobility, intensity, and interdependence of activities can influence land use pattern. After performing a set of experiments within the framework of this model, we compare the implications of each condition for the corroboration of specific land use patterns. Some historical and archaeological implications are also discussed. We suggest that the overall extension of farming in oases can be explained by the competition for land use between farming and herding, assuming that it develops with little or no interference of climatic, geographical, and historical contingencies.     

Faunal acquisition,maintenance, and consumption: how the Teotihuacanos got their meat

The compilation of the last 40 years of zooarchaeological exploration at Teotihuacan, Mexico, provides a unique opportunity to create more nuanced models of New World vertebrate consumption that did not focus on domesticated animals (dog and turkey). Any single model of ancient food systems fails to represent how varied ecological and social contexts led to a complex web of adaptations, and here, it is argued that Teotihuacan’s arid, highland, and urban environment contributed to a distinct faunal acquisition strategy. Intra-site variation and diverse degrees of animal procurement and management were practiced throughout the site. For example, the low proportion of deer compared to the abundant evidence of rabbit/hare consumption suggests small-scale animal management and breeding programs in the residential complexes supplemented with opportunistic garden hunting and meat purchased through a market economy. Such foodstuffs would have been both more predictable and readily made available to organize large feasting events, a possibility that is strengthened by evidence of extraordinarily high abundances of rabbits in ceremonial contexts.     

Exploring chronic arsenic poisoning in pre-Columbian Chilean mummies

This paper explores to what extent arsenic poisoning affected pre-Columbian northern Chile populations living between Arica and Iquique cities. We hypothesize, the pre-Columbian inhabitants of this region, will show arseniasis according to modern geographic endemic levels. Continuous exposure to high levels of arsenic causes serious health problems. Today, in the Camarones valley, where many Chinchorro people lived, arsenic levels are 100 times above the 10 μg/L recommended by the World Health Organization (WHO). Using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) we determined arsenic levels in a single strand of hair of 45 Arica mummies coming from ten sites (Morro 1, Morro 1/5, Yungay 372, Camarones 8, 9, 15D, and 17 and Azapa 140, Sermenia and Patillos), ranging from Chinchorro (ca. 5000–2000 years B.C.) to the Late Intermediate Period (1000–1400 years A.D.). Each hair was cleaned using distilled ionized water and placed on double sided mounting tape and ablated using a 266 nm Nd-YAG UV laser. Hair samples were also investigated for potential diagenesis.     

Making Territory Visible: The Revenue Surveys of Colonial South Asia

Once the British became a colonial power in south Asia in the eighteenth century, they had to struggle to determine the internal divisions and boundaries of the territories under their control. In north India, these units had been organized around various pre‐colonial administrative divisions, such as parganas, which had never been mapped. With the introduction of detailed revenue (cadastral) surveys in the early nineteenth century, the British were able to map the parganas and other administrative units, thereby creating a durable record of property holdings. In the nineteenth century, they also allowed the colonial administrators to reorganize the old divisions into a well‐defined and more coherent pattern that endured to form the geographical template of the modern state.     

Breccia verde di Sparta,an elusive decorative stone used in antiquity

Breccia verde di Sparta is the traditional name given by the Roman marmorarii of the 19th century to a brecciated volcanic rock whose unknown precise provenance has been determined here for the first time through exploration of the broader area of Psefí (south of Krokees, province of Sparta, Peloponnese, Greece). This location was well known in antiquity and in modern times for having been exploited by the Romans for an important green porphyry named lapis lacedaemonius, nowadays also known as porfido verde antico. This breccia has been seldom used in Roman times for opera sectilia; in contrast, it appears more frequently reused in medieval floors; it is also frequently present in historical lithotecs formed in the 19th and 20th centuries. To fully characterise it and determine its relationships with green porphyry, breccia verde di Sparta samples from the newly discovered source have been thoroughly studied minero-petrographically and geochemically, and their complex genesis has been reconstructed. It appears that after extrusion the original brecciated basaltic andesite underwent extensive hydrothermal low-grade metamorphism, with a complete alteration of the igneous assemblage and minerals that preserved only part of the clinopyroxene phenocrysts. Alteration was accompanied by crystallisation of abundant epidote and chlorite, which imparted its predominant green colour to the rock. These breccias intruded in the lithoclases of the porphyry.