Reviews

AIDS in Africa: The Social and Policy Impact edited by Norman Miller and Richard C. Rockwell Edwin Mellen Press, Lewiston (New York) and Queenston (Ontario), 1988. xxxi plus 336 pp. including map, tables, figures, notes, appendices and selected bibliographies. $110,00.

The Politics of Africa's Economic Stagnation by Richard Sandbrook Cambridge University Press, Cambridge, 1985. xiii plus 180 pp. including map, tables, notes and index. R.25,50 paperback.

Imperialism and Dependency: Obstacles to African Development by Daniel A. Offiong Howard University Press, Washington, DC, 1982. 304 pp. including tables, bibliography and index. $6,95 paperback.

Early Field Recordings: A Catalogue of Cylinder Collections at the Indiana University Archives of Traditional Music edited by Anthony Seeger and Louise S. Spear Indiana University Press, Bloomington, 1987. xviii plus 198 pp. $22,50.

Western Sahara: The Roots of a Desert War by Tony Hodges Lawrence Hill and Co., Westport (Connecticut), 1983. xii plus 388 pp. including maps, illustrations, tables, notes, appendix, bibliography and index. £6,95 paperback.

Somalia: Nation in Search of a State by David D. Laitin and Said S. Samatar Westview Press, Boulder (Colorado), and Gower, London, 1987. xvii plus 198 pp. including maps, illustrations, figures, tables, notes and index. $28,00.

Superpower Diplomacy in the Horn of Africa by Samuel M. Makinda Croom Helm, London and Sydney, 1987. 242 pp. including notes, appendices, select bibliography and index. £22,50.

Industrialization in West Africa by J.O.C. Onyemelukwe Croom Helm, London, 1984. v plus 226 pp. including tables, figures, bibliography and index. £17,95.

Modern Kongo Prophets: Religion in a Plural Society by Wyatt MacGaffey Indiana University Press, Bloomington, 1983. xiii plus 285 pp. including tables, figures, illustrations, notes, references and index. $12,00 paperback.

Naissance du Mozambique: Résistance et Révoltes Anticoloniales, 1854–1918 (Two Volumes) by René Pélissier Editions Pélissier, Orgeval (France), 1984. 833 pp. including maps, tables, notes, bibliography and index. $45,00 paperback.

The Political Economy of Namibia: An Annotated, Critical Bibliography by Tore LinnÉ Eriksen with Richard Moorsom Scandinavian Institute of African Studies, Uppsala, 1985. 423 pp. including map and authors’ index. SEK 110.

The Bureaucratic Struggle for Control of US Foreign Aid: Diplomacy versus Development in Southern Africa by Caleb Rossiter Bowker Publishing Co., Epping (England), and Westview Press, Boulder (Colorado), 1985. xiii plus 250 pp. including figures, tables, notes, bibliography and index. $25,50 paperback.

The Politics of Economic Power in Southern Africa by Ronald T. Libby Princeton University Press, Princeton (New Jersey), 1987. xxiii plus 361 pp. including maps, tables, bibliography and index. $45,00. $14,50 paperback.

South Africa in Crisis edited by Jesmond Blumenfeld Croom Helm, London, 1987. x plus 207 pp. including tables, notes and index. £19,95.

Pass Controls and the Urban African Proletariat in South Africa By Doug Hindson Ravan Press, Johannesburg, 1987. xii plus 121 pp. including notes, bibliography and index. R 14,00 paperback.

Hidden Struggles in Rural South Africa: Politics and Popular Movements in the Transkei and Eastern Cape, 1890–1930 by William Beinart and Colin Bundy Ravan Press, Johannesburg, 1987. xxvi plus 326 pp. including illustrations, maps, notes and index. R24,00 paperback.     

The Downstream Benefits of Experimentation

The debate about the cost-effectiveness of randomized fieldexperimentation ignores one of the most important potentialuses of experimental data. This article defines and illustrates"downstream" experimental analysis—that is, analysis ofthe indirect effects of experimental interventions. We arguethat downstream analysis may be as valuable as conventionalanalysis, perhaps even more so in the case of laboratory experimentation.     

Driver and front seat passenger fatalities associated with air bag deployment. Part 2: A review of injury patterns and investigative issues

Assessment of the role of air bag deployment in injury causation in a crash of any severity requires analysis of occupant, vehicle, and impact data. The potential injurious role of an air bag is independent of crash severity and is more obvious in minor collisions, particularly those involving "out-of-position" occupants. Factors such as occupant height and other constitutional and medical factors, intoxication, age, type, and proper use of other restraint systems, pre-impact braking and multiple impacts can contribute to an occupant being "out-of-position." Two injury mechanisms are described in out-of-position occupants: "punch-out" when the individual covers the air bag module before deployment and "membrane-force" when the occupant contacts a partly deployed air bag. Each mechanism is associated with injury patterns. In adults, "punch-out" can cause thoraco-abdominal trauma and "membrane-force" loading can lead to craniocervical injury. This can also occur in short-statured occupants including children subjected to both types of loading. In more severe collisions, other factors, e.g., intrusion, steering column and seatbelt loading and other occupant compartment contacts, can contribute to trauma.     

Ego identity status and decision styles

It was hypothesized that the decision processes used in coping with the identity crisis would be related to more general decision styles in that identity achievers and moratoriums would tend to be reflective in their conceptual tempo while foreclosures would typically be impulsive. No prediction was made about identity diffusions. Ninety-two male college students were given an identity status interview and the Matching Familiar Figures Test. The results were consistent with the hypotheses, and in addition it was found that identity diffusions were generally impulsive. Since conceptual tempo has been found to be well established in childhood, the results of this study have implications for the early prediction of adult identity status.Received Ph.D. from SUNY/Buffalo. Recent research has been mainly concerned with the development of ego identity and correlates of the different identity statuses.Received Ph.D. from SUNY/Buffalo. Recent research has been mainly concerned with the development of ego identity and correlates of the different identity statuses.     

Attrition in the new beneficiary survey and followup, and its correlates

Panel surveys interview the same individuals more than once over a period of time. Attrition from the survey occurs when those individuals die, refuse to be interviewed again, or, for some other reason, cannot be contacted. If the original sample was representative of a specific population, then survey analysis may provide misleading conclusions about changes in population characteristics over time if these individuals leave the sample in a nonrandom way. Therefore, it is important to identify the characteristics of individuals who leave the survey for various reasons. This article explores the extent of and reasons for attrition in the New Beneficiary Survey (NBS) between the first interview in 1982 and the followup interview in 1991. Presented is a comparison of the characteristics of survivors (the reinterviewed sample) with attriters (those in the sample not reinterviewed) from the retired-worker and disabled-worker samples. The article explores a variety of potential determinants of attrition to the probability of attrition. These determinants are examined alone and in a multivariate framework. The NBS sample population is drawn from and linked to Social Security Administrative records, which have exact matched data on mortality as a cause of attrition. These data do not depend on survey-reported reasons for attrition; hence, it allows the examination of the differences in the patterns and predictors of attrition due to death and due to other reasons, primarily, the refusal to be interviewed. Attrition due to death must be identified precisely because misidentification of death as refusal to be interviewed may lead researchers to infer more selective attrition than might be the case. Different patterns of attrition are evident in the comparison of attrition levels and the determinants of attrition for the retired and disabled samples, both composed of persons with relatively high mortality risk. In particular, individuals' health, health insurance coverage, and level of education have different impacts on their likelihood of attrition. In general, it appears that refusal to be interviewed is more evenly spread across populations and characteristics than is death. The analysis shows that attrition due to death and attrition due to refusal are quite different processes, even though health conditions play a role in both processes. The results suggest that because attrition patterns (including death) may be quite different across population samples, sample-specific attrition patterns must be analyzed over the lifetime of any panel study. Long-term studies of panel attrition are necessary to provide researchers analyzing the data with information on potential biases due to nonrandom attrition.     

Can We Start to Understand Emergence?

When a new property is required to characterise an altered system, it is said to be 'emergent'. The fundamental importance of emergence for social activists is stressed. It is proposed that we deepen our understanding of it by examining well-understood processes to see exactly how new properties emerge in them. Reasons are given for hoping that this approach can be more fruitful now than in past eras. To illustrate the method, a simple case is examined which brings out inter alia the role of the environment and the precise way that a continuous process underlies the abrupt emergence. The results appear encouraging enough to stimulate further studies along these lines, and it is suggested where suitable cases can be found.