Principal curves revisited

A principal curve (Hastie and Stuetzle, 1989) is a smooth curve passing through the middle of a distribution or data cloud, and is a generalization of linear principal components. We give an alternative definition of a principal curve, based on a mixture model. Estimation is carried out through an EM algorithm. Some comparisons are made to the Hastie-Stuetzle definition.     

Fertility decline in Nigeria: the case of Ekpoma Region,Bendel State

Data concerning 624 randomly selected mothers in Ekpoma Region, Nigeria, are used to analyze socioeconomic and cultural determinants of fertility. Factors considered include education, occupation, income, religion, age at first marriage, breast-feeding, and contraceptive practice. The author concludes that the conditions for fertility decline are now in place and that this decline could be accelerated by discouraging early marriage, increasing female education, and promoting contraception.     

Return migration from Australia: a case study

"The study investigates the departure from Australia of former settlers who arrived during the 1980 calendar year. The 1980 settler arrival cohort [consists] of 75,167 visaed migrants.... The study has three main aims: (i) to analyse departures from Australia of the 1980 settler arrival cohort with a view to gauging the success of Australia's immigration program in retaining settlers; (ii) to examine the retention rates of settlers with respect to characteristics...including age, sex, marital status, country of last residence, and settler eligibility category; and (iii) to consider implications of the findings." Australia's present immigration policy is discussed, previous research on return migration from Australia is summarized, and a detailed analysis of the departure data is presented. "This study found that by August 1984, 12.4 per cent of non-refugee settlers who arrived in Australia during 1980 had departed permanently but that only 0.6 per cent of the 1980 refugee cohort had done so." These figures represent a decline in immigrant departure rates since the 1960s and early 1970s. Small differences in departure rates by place of birth, age, and marital status, which may have demographic consequences if sustained over time, are noted. (SUMMARY IN FRE AND SPA)     

Migration of the rural population under conditions of agro-industrial integration

Factors affecting rural-urban migration in the USSR are examined. The author suggests that a lower rate of such migration is associated with the creation of agro-industrial centers.     

Book reviews

Nathan Glazer Ethnic Dilemmas Harvard, Harvard University Press. 1985

Giddens, Anthony The Constitution of Society, Berkeley, University of California, 1985, pp.XXXVII, 402. Notes, glossary, diagrams, bibliographic notes and index.

Jeremy Rifkin Declaration of a Heretic. Boston. London, Melbourne and Henley, Routledge and Kegan Paul, 1985, pp.X,140.

Ted Benton The Rise and Fall of Structural Marxism: Althusser and his Influence, New York, St.Martin's Press, 1984, pp. VII,259.

Raymond L. Garthoff Détente and Confrontation Washington, The Brookings Institution, 1985, pp.XVI,1126.

Joseph J. Collins The Soviet Invasion of Afghanistan. A Study in the Use of Force in Soviet Foreign Policy, Massachusetts/Toronto, D.C. Heath and Company/Lexington, 1986, pp. XV, 195.

Jan Shipps Mormonism: The Story of a New Religious Tradition, Chicago, University of Illinois Press, 1985, pp.211.

Robert Jay Lifton Home from the War: Vietnam Veterans: Neither Victims nor Executioners, New York, Basic Books, 1985, pp.478     

Understanding manager resistance to blockchain systems

Blockchain technology has received much attention in the media and there is an increasing interest amongst organizations within financial services due to the potential benefits. As blockchain-based systems are a nascent technology, the requirements of the technology need to be understood, to allow blockchain systems to be successfully integrated within financial service organizations. There are gaps in academic research in understanding how managers evaluate the value of a blockchain-based system. This study develops a model to explain manager resistance to implementing blockchain-based systems in financial services organizations. This research advances the theoretical understanding of managers’ perspectives on blockchain-based systems and models their resistance to blockchain technology.     

Estimating the National High School Dropout Rate

Recent interest has focused on the high school dropout rate as one indicator of the national education picture. Empirical estimates of this "rate" vary considerably, because these estimates are poorly defined. This article reviews some of the current measures and presents a new measure of the high school dropout rate--the proportion of high school students who drop out in a defined period of time (1 year). The estimates show that the national yearly high school dropout rate was about the same in 1985 as it was in 1968. Improvement has occurred, however, since 1968 for specific racial groups as well as for some grade levels.     

Pluralism and ethnic conflict in Tanzania's arid lands: the case of the Maasai and the WaArusha

In Tanzania, the Maasai and Waarusha tribes are experiencing conflict because differences in their modes of productions and economic strategies undermine the peaceful coexistence that they have enjoyed since the 18th century. The Maasai are pastoralists, while the Waarusha are agricultural subsistence farmers who are encroaching on the best pasture lands. A sketch of the history of the two groups shows that the Maasai reached the peak of their land holding in 1880 before the arrival of European colonists who seized land and restricted the Maasai to a semi-arid reserve but allowed the Maasai to remain an autonomous and powerful group. The Waarusha began encroaching on Maasai land after independence due to land and population pressure. While closely tied, each group looks down on the other, and Maasai ascendancy has given way to Waarusha challenges. After independence, the tribal and ethnic rule that was protected by the colonial system was disrupted to allow for increased internal migration and new patterns of settlement. The rights of land ownership were transferred from tribes to the State, allowing privileged groups to benefit. The Waarusha began to engage in illegal land-grabbing and to encroach on the Maasai preserve using legal and illegal means. The Maasai view land as collective property and have had difficulty retaining title of traditional lands in the face of population pressure. This loss of grazing land has forced the Maasai into a mixed economy that depends upon agricultural production as well as livestock production. In the meantime, the Waarusha have deliberately sought political office to gain power to secure their holdings. Immediate action is needed to produce 1) a policy on spontaneous settlement, 2) an immediate adjustment of legal procedures for land acquisition, 3) a land tenure policy that equally emphasizes agricultural and livestock production, and 4) controls on undue expansion of subsistence agriculture into semi-arid rangelands.     

DO SURVEYS OVERSTATE PUBLIC CONCERNS?

Because the item, "How concerned are you about...?" asks respondentsto indicate their level of concern about an issue, some respondentsmay sense it assumes they are concerned or should be concernedabout the issue. Using a filter question to first determineif people are concerned about the issue before asking for theirdegree of concern may help solve this problem. To test thishypothesis, a split-ballot experiment was embedded in a nationalrandom digit dialing telephone survey on food-related issues.For the four items included in the experiment, the group receivingthe filter versions of the questions gave roughly double thepercentages of "not concerned" responses as the group receivingstandard items, and the filter group also gave fewer responsesat the upper end of the response scale.     

Psycho-social impacts of terrorism and organized crime: The counterfinality of the practico-inert

The phrase, the counterfinality of the practico-inert is from Sartre with reference to implications of modern technology as a shorthand for that enormous properly human and anti-natural power of dead human labor stored up in our machinery — an alienated power, which turns back on and against us in unrecognizable forms and can symbolize the massive dystopian horizon of organized crime as well as individual terrorist praxis (Jean-Paul Sartre (1948).Situations II. Paris: Gallimard).