HIGH-TECHNOLOGY JOBS AND WORKER MOBILITY*

ABSTRACT. The premise of this paper is that one can discover much about the location determinants of high-technology industry by examining the location (migration) decision of workers with high-technology occupations. A model of the high-technology worker migration decision is developed that permits estimation of worker response to both personal and area characteristics, the latter chosen to mirror location factors often cited by high-technology firms as important for both the attraction and retention of their specialized work force. Logit estimates of this model between 1975 and 1980 are presented. The paper is concluded with a discussion of policy implications.     

ON THE STABILITY OF HOUSING SECTOR INTERACTION: EVIDENCE FROM 42 METROPOLITAN AREAS*

ABSTRACT. Residential vacancy chain models based on White's (1971) application of Markov chain theory are used to simulate flows of housing vacancies through a set of interdependent housing market sectors. Measures of housing sector interaction are derived from such models. Our purpose here is to address the issue of time stationarity raised by their use. U.S. census data are available to calibrate such models at two, and sometimes three, points in time. Data from 42 different SMSAs are used to generate 56 cross-temporal comparisons with interobservation periods ranging from three to eight years. Stability of interaction is addressed from two perspectives–the sectoral perspective and the areawide perspective. Results are mixed and depend upon which measure of interaction is used, which perspective is addressed, and the duration of the interobservation period. However, within limits, findings support continued use of vacancy chain models.     

EVALUATION OF THE MANGANESE ESR METHOD OF MARBLE CHARACTERIZATION

Results suggest that ESR studies of Mn⁺² in marble can provide an excellent discriminator for the determination of marble provenance. In comparison with other methods of quantitative analysis for manganese such as AA or NAA, the ESR method determines only Mn⁺² rather than total Mn, is inexpensive and rapid with no chemical preparation required, and does not consume the sample.     

Fire and its roles in early hominid lifeways

Discovery of the uses and later the invention of fire-making are fundamental to humanity. Following reports over the last decade of traces of fire found on Lower Pleistocene archaeological sites in eastern Africa, the dating of the control of fire by hominids has become a controversial issue. In this paper we critically review the contexts and, in the light of a battery of archaeometric techniques, the nature of reported instances of fire from Koobi Fora and Chesowanja in Kenya, and from Gadeb and the Middle Awash in Ethiopia. We conclude with a discussion of the roles fire may have played in the lifeways of early Pleistocene savanna-living hominids.

---

Résumé La découverte des usages du feu et ensuite de sa préparation est fondamentale pour l'humanité. Suite à des rapports au cours de la dernière décennie signalant des traces de feu relevées dans des sites archéologiques du Pléistocène inférieur dans l'est de l'Afrique, la datation du contrôle du feu par les hominiens est devenu une source de controverse. Dans cet article, nous révisons d'un oeil critique les contextes et la nature des cas de feu signalés à Koobi Fora et à Chesowanja au Kenya, et à Gadeb et dans l'Awash moyen en Éthiopie, à la lumière d'une suite de techniques archéometriques. Suit en conclusion une discussion sur les rôles qu'aurait pu jouer le feu dans les modes de vie des hominiens vivant dans les savannes du Pléistocène inférieur.