Stable Oxygen and Carbon Isotopic Compositions of Lates stappersii Otoliths from Lake Tanganyika,East Africa

In this study, we measured growth trends in oxygen and carbon isotopic ratios in whole sagittal otoliths from three adult centropomid fish (Lates stappersii) from each of three sub-basins of Lake Tanganyika, East Africa. Sampling density was 20 to 50 samples per otolith. Both δ¹⁸O and δ¹³C values increase with age. The δ¹⁸O data suggest that otoliths were precipitated near the expected equilibrium with the ambient environment (ca. +3.5‰) and support a migration pattern from surface waters during larval stages to deeper waters (40 to 80 m) for mature fish. Relatively high δ¹⁸O values in the southern sub-basin are consistent with cooler temperatures in the region during seasonal upwelling. The δ13C increase from otolith core to edge is large (up to 4‰) and is interpreted as due to ontogenetic changes in diet and contributions from a decrease in the proportion of respired CO₂ incorporated into otolith carbonate as metabolic rates of the fish dropped with maturity. The data seem to successfully reveal life strategy and migration patterns of L. stappersii, document regional differences in lake conditions, and provide a record of temperature within the water column during which the fish lived. Higher resolution studies and analyses of historical samples could be used to constrain modern and past growth patterns, and to reconstruct past temperature gradients and productivity patterns in the lake.     

Understanding Urban Inequality: A Model Based on Existing Theories and an Empirical Illustration

In the debate on urban inequality, Sassen’s theory on social polarization and Wilson’s theory on spatial mismatch have received much attention. Where Sassen highlights the decline of the middle classes, Wilson focuses on the upgrading of urban labour markets. In this article we argue that both theories may be valid, but that they have to be put in a more extended theoretical framework. Of central importance are national institutional arrangements, membership of different ethnic groups and networks, and place–specific characteristics rooted in local socio–economic histories. As a first empirical illustration of our model, we use data on the labour markets of Amsterdam and Rotterdam and show that different forms of inequality can be found both in economic sectors and within ethnic groups. The model we present could be used both to reinterébatpret existing data and as an analytical framework for the analysis of different forms of urban inequality. Dans le d& sur l’inégalitéurbaine, la théorie de la polarisation sociale de Sassen et celle de la disparité spatiale de Wilson ont retenu l’attention. Alors que Sassen souligne le déclin des classes moyennes, Wilson s’attache à la revalorisation des marchés du travail urbains. Cet article soutient que, si ces deux théories sont admissibles, elles doivent étre placées dans un cadre théorique plus large. En effet, sont essentielles les dispositions institutionnelles nationales, l’adhésion de différents réseaux et groupes ethniques, et les spécificités du lieu enracinées dans les histoires socio–économiques locales. Comme première illustration empirique de notre modèle, nous utilisons des données relatives aux marchés du travail d’Amsterdam et de Rotterdam pour montrer qu’il y existe différentes formes d’inégalitéà la fois dans les secteurs économiques et les groupes ethniques. Le modèle présenté pourrait servir à réinterpréter les données existantes et fournir un cadre à l’analyse des diverses formes d’inégalité urbaine.     

Book review

Built by Japan: Competitive Straegies of the Japanese Construction Industry, Fumio Hasegawa & Shimizu Group FS New York, John Wiley & amp; Sons, 1988, 204 pp., US$25.00.

Technological Change at Work Ian McLouglin & Jon Clark Milton Keynes, Open University Press, 1988, 202 pp., Pb £9.00, Hb £25.00.

Enterprising Innovation: An Alternative Approach Veronica Mole & Dave Elliott London, Frances Pinter, 1987, pp. 180.

Flexible Automation: The Global Diffusion of New Technology in the Engineering Industry Charles Edquist Jacobsson Oxford, Basil Blackwell, 1988, Hb £35.00.

Expert Systems: Strategic Implications and Applications A. Beerel Chichester, Ellis Horwood Ltd, 1988, 173 pp., £22.50.     

From individual skills to organizational capability in Japan

Two contrasting conceptualizations of skills lead one to attributedifferent roles to inter-firm networks. If skills are regardedas a public good, then inter-firm networks are like clubs thatpolice the scope for firms to benefit from skills without payingfor their acquisition. By contrast, if skills are regarded asa distinct and hard-to-imitate asset, then inter-firm networksprovide an essential non-market mechanism for spreading it.The problem in the former conceptualization is market failuredue to the ease of spill-over of knowledge, while the counterpartproblem in the latter conceptualization is the difficulty ofdiffusing tacit knowledge by market mechanisms. This paper describesToyota Motor Corporation's supplier development programmes inthe wider industrial context of Japan. It concludes that ofthe two perspectives, the knowledge-as-a-distinctive-asset perspectiveis more appropriate in understanding the rationale behind theelaborate mechanisms for developing suppliers in the long term.     

Outsourcing and Offshoring: Implications for Productivity of Business Services

This paper reviews the implications of outsourcing and offshoringfor the productivity of business services in the UK. Officialstatistics indicate that business-service productivity has grownby over 20 per cent in the last 7 years at the same time asemployment grew by 20 per cent. The paper considers possiblefactors that account for the simultaneous growth of employmentand productivity. First, we discuss outsourcing and offshoring,and their role in enhancing productivity through greater specialization,standardization, and consolidation of business processes, anda shift to higher value-added services. Outsourcing of businessservices is interpreted as part of corporate restructuring,namely as the unbundling of corporate functions as well as verticaldisintegration. Second, as some services become more like products,both low-skilled and high-skilled jobs are subjected to productivitygrowth through standardization and digitization. It is argued,however, that the future of business-service productivity ison a knife-edge, depending on the mix of two sources of productivityenhancement—namely greater standardization and capturingvalue from customized solutions. Footnotes ¹ E-mail addresses: mari.sako{at}sbs.ox.ac.uk     

Book review

Built by Japan: Competitive Straegies of the Japanese Construction Industry, Fumio Hasegawa & Shimizu Group FS New York, John Wiley & amp; Sons, 1988, 204 pp., US$25.00.

Technological Change at Work Ian McLouglin & Jon Clark Milton Keynes, Open University Press, 1988, 202 pp., Pb £9.00, Hb £25.00.

Enterprising Innovation: An Alternative Approach Veronica Mole & Dave Elliott London, Frances Pinter, 1987, pp. 180.

Flexible Automation: The Global Diffusion of New Technology in the Engineering Industry Charles Edquist Jacobsson Oxford, Basil Blackwell, 1988, Hb £35.00.

Expert Systems: Strategic Implications and Applications A. Beerel Chichester, Ellis Horwood Ltd, 1988, 173 pp., £22.50.