This article introduces to the statistical and insurance literature a mathematical technique for an a priori classification of objects when no training sample exists for which the exact correct group membership is known. The article also provides an example of the empirical application of the methodology to fraud detection for bodily injury claims in automobile insurance. With this technique, principal component analysis of RIDIT scores (PRIDIT), an insurance fraud detector can reduce uncertainty and increase the chances of targeting the appropriate claims so that an organization will be more likely to allocate investigative resources efficiently to uncover insurance fraud. In addition, other (exogenous) empirical models can be validated relative to the PRIDIT-derived weights for optimal ranking of fraud/nonfraud claims and/or profiling. The technique at once gives measures of the individual fraud indicator variables' worth and a measure of individual claim file suspicion level for the entire claim file that can be used to cogently direct further fraud investigation resources. Moreover, the technique does so at a lower cost than utilizing human insurance investigators, or insurance adjusters, but with similar outcomes. More generally, this technique is applicable to other commonly encountered managerial settings in which a large number of assignment decisions are made subjectively based on "clues," which may change dramatically over time. This article explores the application of these techniques to injury insurance claims for automobile bodily injury in detail.

Fraud Classification Using Principal Component Analysis of RIDITs

Child survival in big cities: the disadvantages of migrants.

Analysis of the 1986 Senegal Demographic and Health Survey reveals that mothers may be able to improve their children’s survival chances by migrating from the countryside to the city. Children of urban migrants, however, continue to experience a much higher risk of mortality before the age of 5 than children of urban nonmigrants, even after the mother has lived in the city for several years. This migrant mortality disadvantage persists when controlling for numerous socioeconomic and fertility-related factors typically associated with child mortality in developing countries, which also serve as indicators of migrant selection and adaptation.

Rural-to-Urban migration and child survival in Senegal

Utilization of health care in an African urban area: Results from a household survey in Ouagadougou, Burkina-Faso

Evidence regarding the effects of health status on migration are mixed with some concluding that there is a positive relation while others conclude a negative relation. This study examines the analytical bases for conflicting findings and proposes a model of the health-migration relation which allows for age selectivity nonlinearities interactions and dynamic effects. Often in migration research we focus on migrant-nonmigrant differentials which helps us to understand the cross-sectional differences between the 2 groups of persons but it does little to elucidate the complex process by which nonmigrants become migrants. The sequence of migration and health events from the US National Health Interview Survey from 1979-1980 show that for the population under age 45 there is little temporal connection between migration and health status changes. 2/3 of the younger population with at least 1 health or migration event migrated only with health status changes neither preceding nor following the migration. Since the migration and health events for these persons are not associated in time there is little basis for positing strong relations of either direction for the nonelderly. The age groups for which migration and health events are connected in time are those over age 45 and the temporal proximity becomes even more marked for the elderly. Among the elderly the migrant-only group constituted only 10% of those with at least 1 event. As expected for the elderly the dominant relation is health deterioration after migration the pattern displayed by 65% of the elderly with events in the last 5 years. The elderly are also more likely to be in the Destabilized Migrant category experiencing health status declines both before and after migration. This is also consistent with the theory that the elderly in poor health at the time of migration will be more likely to be stressed by their migration and experience further deteriorations in health. The conditional probabilities indicate that health status declines are unlikely to precipitate immediate migrations except for those with pre-existing serious conditions or more severe activity limitations. (authors modified)

The directionality and age selectivity of the health-migration relation: evidence from sequences of disability and mobility in the United States.

Health effects of rural-urban migration in developing countries—Senegal☆

La migration à large éclrelle vers les villes constitue l'un des cliangerneitts sociodémographiques profonds qui se produisent à l'heure actuelle dans le monde, en particulier dans les pays du tiers inonde. Par ailleurs, il y a longtemps qu'on a remarqué que la vie urbaine était associée à une ailginentation du risque de nialadie. Afin de mieux comprendre les effets de la migration urbaine sur la santé, et d'autre part, d'essayer d'assister les responsables de la planifkation et de la gestion des services de santé, l'OMS a développé et inis sur pied, en collaboration avec des pays tels que le Sénégal, l'Iran et la NouvelleZélande, quelques études sur ce tlième. L'étude collective a ét& réalisée au Sénégal en 1970-1973 par l'organisation mondiale de la Santé, l'Université de Dakar et l'OfJice de la Recherche scientifique et technique Outre-Mer avec l'assistaiice technique du Ministère de la Santé publique et des Affaires sociales. C'est une enquête ponctuelle dont l'objectif est l'étilde de la migration urbaine et de ses effets sur la sante d'un échantillon de migrants Sérer originaires de l'Arrondissement rural de Niakhar, résidant à Dakar au moinent de l'enquête. C'est aussi, et surtout, une recherche appliquée destinée à comparer deux écchantillons ruraux et urbains du triple point de vue socio-démographique, de la santé physique et inentale et enfin de l'habitat-hygiène. L'analyse de l'éclzantillon urbain est conçue de façon à permettre de déterminer les conditions d'adaptation à la vie urbaine des sujets éfudiés. Les ineiiibres de l'épipe collective y voient égalernent la possibilité d'utiliser I'iFlformation à des fins de planijicatioii sanitaire et de tirer des enseignements pour des recherches appliquées futures. Les objectifs de cette etude ont été réalisés. Les résultats méthodologiques et de substance ainsi que les implications pratiques sont présentés ici. .

/pdf/sante-migration-et-urbanisation-une-etude-collective-au-1kwj9rmtat.pdf

Santé, migration et urbanisation: une étude collective au Sénégal

The definition and measurement of disability.

During 1970-1973 a study was done on the Serer a Senegalese tribe known to have difficulty in adapting to new situations. The study was done by the World Health Organization and the University in Dakar to determine the health differences if any of those still living in their rural environment and those residing in the city. 262 adults were surveyed in the rural area of Niakhar and 225 Serer natives living in the urban area of Dakir were also surveyed. Questionnaires were prepared dealing with sociodemographic biomedical mental health housing and hygiene data. It was found that urban dwellers tended to be younger than their rural counterparts. There was also a greater percentage of Serer women who live in the city. Education was higher among those who lived in Dakar with male urban dwellers having a 13% higher ratio than women. Serer men who live in the city tend to socialize more with other groups while women mixed poorly saying that other cultures had "doubtful morality." Women who moved to Dakir trusted modern medicine while urban dwelling men believed both in modern and folk medicine. 3 areas of medical concern were studied: precursors to heart disease anemia and infectious diseases. Little difference was observed between rural and urban populations for precursors to heart disease. Anemia was common in the rural area for both sexes. More malaria intestinal parasites and tuberculosis were found in rural households. In regard to mental health depression and anxiety are approximately the same for urban and rural dwellers while psychiatric syndrome cerebral syndromes and personality disorders do appear more frequently in urban dwellers. The authors discuss the practical implications of their study and suggest further research that can be done to extend their analysis. (summary in FRE)

Migrants' health and adjustment to urban life--Senegal.

Lamigration a large e&chelle verslesvilles constitue l'undeschangements sociodemographiques profonds quiseproduisent al'heure actuelle danslemonde, enparticulier danslespaysdutiers monde. Parailleurs, ilyalongtemps qu'on aremarque quelavie urbaine e'tait associe'e auneaugmentation durisque demaladie. Afindemieuxcomprendre leseffets delamigration urbaine surlasante, etd'autre part, d'essayer d'assister lesresponsables delaplanification etdelagestion desservices desante, l'OMSadiveloppe et missurpied, encollaboration avecdespaystels queleSene'gal, l'Iran etlaNouvelleZe'lande, quelques e'tudes surcetheme. L'etude collective ae'te re'alise'e auSenegal en1970-1973 parl'Organisation mondiale delaSante, l'Universite deDakaretl'Office delaRecherche scientifique ettechnique Outre-Mer avecl'assistance technique duMinistere delaSante publique etdesAffaires sociales. C'est uneenque'te ponctuelle dontl'objectif estl'etude delamigration urbaine etdeseseffets surlasante d'unechantillon demigrants Serer originaires del'Arrondissementrural deNiakhar, residant aDakaraumomentdel'enquezte. C'est aussi, etsurtout, unerecherche appliquee destine'e acomparer deuxechantillons ruraux eturbains dutriple point devuesocio-demographique, delasante physique etmentale etenfin del'habitat-hygie' ne. L'analyse del'echantillon urbain estcon!Vue defaCon apermettre dedeterminer lesconditions d'adaptation a lavieurbaine dessujets etudies. Lesmembres del'e'quipe collective yvoient e'galement lapossibilite d'utiliser l'information a desfins deplanification sanitaire etdetirer desenseignements pourdesrecherches appliquees futures. Lesobjectifs decette etude ontete' realise's. Lesre'sultats methodologiques etdesubstance ainsi quelesimplications pratiques sont presentes ici.

J.L. Cutler

Papers

Health effects of rural-urban migration in developing countries—Senegal☆

Santé, migration et urbanisation: une étude collective au Sénégal

The definition and measurement of disability.

Migrants' health and adjustment to urban life--Senegal.

Sante, migration eturbanisation Uneetudecollective auSenegal