Essays on the causes of migration

This thesis consists of three chapters. All three are linked by our desire to better understand the determinants of labour migration; that is, the motivation for a person to change his or her location of residence for a period of at least a year. While immigration receives much public discourse, the economic evidence on how migrants self-select is still lacking. In particular, we have little evidence on the relative importance of determinants. We focus on three areas that have received substantially less attention in the migration literature: the importance of relative versus absolute income motives for migration; the effect of wealth and intertemporal choice on return migration; and the role of place attachment as an obstacle to labour mobility. Common to all three chapters is an emphasis on counterbalancing forces that tend to offset spatial income differentials in determining migration. The first chapter examines the extent to which relative income – that is, one’s position in the income distribution – matters in migration choice. Virtually all studies of migration focus on absolute income. This is at odds with the mounting evidence that suggests people care about their relative position in the income distribution. We argue that, in order to test between the absolute income and relative income theories of migration, one needs individual-level panel data on before and after migration outcomes. Indeed, since one has to estimate counterfactual migrant earnings of non-migrants, if migrants are selected on unobservables then cross-sectional estimates will systematically bias the predicted migrant earnings of non-migrants. We estimate the relative importance of the two main theories in explaining interstate migration in the U.S. using a panel of individuals. Relative income is calculated with respect to those persons in the same U.S. state. We find that, although migration leads to a substantial rise in absolute income, the trigger for migration is low relative income and not low absolute income. In the second chapter we show analytically that, under some conditions, return migration is optimal. We build a model where consumers choose either to never migrate, permanently migrate or, migrate and subsequently return. To generate an incentive for return migration, the model assumes a nominal income differential between the source and destination and a compensating differential – which exerts a counterbalancing force to the income differential. Examples of compensating differentials may include differences between the source and destination in climate, place attachment, price levels, unemployment and average consumption. We characterise the optimal migration decision space with respect to the three key variables: initial wealth, the income differential and the compensating differential between the source and destination. The marginal utility of consumption is assumed to be location-dependent due to a non-separable nonpecuniary preference for the source. Consequently, when the region with the best economic opportunities is not the source region, there is a trade-off between income maximisation on the one hand and the marginal utility of consumption on the other. We find that, all else equal, those with low wealth are more likely to migrate and, conditional on migration, those with higher wealth are more likely to return migrate. The third chapter seeks to estimate a key obstacle to migration: place attachment. Place attachment refers to the emotional bonds a person feels towards the place (or area) he or she resides. We estimate place attachment within a tructural model of spatial job search where migration is a by-product of accepting a job offer from another region. The chapter can broadly be split into two parts. The first takes a standard job search model and adapts it to allow search in many potential destinations. Acceptance of an offer from a destination necessarily involves migration to that destination and its associated costs. We consider two types of costs: a cost of migration that is related to distance-to-destination and a non-pecuniary cost of leaving the current region. The latter is deemed to be the negative of place attachment. In the second part, we estimate the structural model for a sample of individual durations in a U.S. state. Our estimates suggest that place attachment is steeply increasing in duration for our reduced-form model; however, the opposite is true for our structural model. We also find that for half the population, the dollar values of place attachment are prohibitively large

Impact de l'Homme sur les milieux naturels : perceptions et mesures

International audienceL'omniprésence de la référence à la nature s'est imposée avec le souci de protection des sites d'abord, de la nature en tant que système vivant ensuite. Mais l'histoire montre que toute une gamme de représentations se sont succédées. De la nature ennemie, on est passé à l'homme ennemi de la nature, jusqu'au moment récent où la réflexion a mis en question le concept même de nature à l'état pur : l'homme n'a-t-il pas imprimé sa marque sur tous les écosystèmes ? Le concept d'anthropisation tente d'exprimer ces effets de façon objective, mais il ne reçoit pas la même acception de tous. L'impact des activités humaines sur les milieux naturels ne peut en effet pas être évalué à partir des mêmes critères par l'agronome, l'économiste, l'écologue, le géographe, le juriste, l'anthropologue, le sociologue,.... et par les différents groupes d'acteurs et d'utilisateurs. Le présent ouvrage tente de rendre compte de cette pluralité à travers le thème « Impact de l'homme sur les milieux naturels-perceptions et mesures ». Sa première partie traite des définitions et représentations de l'anthropisation, la seconde de la dynamique de l'anthropisation à travers des études de cas, illustrant la diversité des situations et des méthodes d'étude, la dernière examine les problèmes et politiques de gestion des milieux. L'ouvrage est issu pour l'essentiel des travaux présentés lors des 7èmes Journées scientifiques de la Société d'Ecologie Humaine qui se sont tenues à Aix-en-Provence en mai 1995 (www.ecologie-humaine.eu

Treatment of malaria from monotherapy to artemisinin-based combination therapy by health professionals in urban health facilities in Yaoundé, central province, Cameroon

<p>Abstract</p> <p>Background</p> <p>After adoption of artesunate-amodiaquine (AS/AQ) as first-line therapy for the treatment of uncomplicated malaria by the malaria control programme, this study was designed to assess the availability of anti-malarial drugs, treatment practices and acceptability of the new protocol by health professionals, in the urban health facilities and drugstores of Yaoundé city, Cameroon.</p> <p>Methods</p> <p>Between April and August 2005, retrospective and current information was collected by consulting registers and interviewing health practitioners in urban health facilities using a structured questionnaire.</p> <p>Results</p> <p>In 2005, twenty-seven trade-named drugs have been identified in drugstores; quinine tablets (300 mg) were the most affordable anti-malarial drugs. Chloroquine was restricted to food market places and no generic artemisinin derivative was available in public health centres. In public health facilities, 13.6% of health professionals were informed about the new guidelines; 73.5% supported the use of AS-AQ as first-line therapy. However, 38.6% apprehended its use due to adverse events attributed to amodiaquine. Malaria treatment was mainly based on the diagnosis of fever. Quinine (300 mg tablets) was the most commonly prescribed first-line anti-malarial drug in adults (44.5%) and pregnant women (52.5%). Artequin^®was the most cited artemsinin-based combination therapy (ACT) (9.9%). Medical sales representatives were the main sources of information on anti-malarials.</p> <p>Conclusion</p> <p>The use of AS/AQ was not implemented in 2005 in Yaoundé, despite the wide range of anti-malarials and trade-named artemisinin derivatives available. Nevertheless, medical practitioners will support the use of this combination, when it is available in a paediatric formulation, at an affordable price. Training, information and participation of health professionals in decision-making is one of the key elements to improve adherence to new protocol guidelines. This baseline information will be useful to monitor progress in ACT implementation in Cameroon.</p

Treatment of malaria from monotherapy to artemisinin-based combination therapy by health professionals in rural health facilities in southern Cameroon

<p>Abstract</p> <p>Background</p> <p>One year after the adoption of artesunate-amodiaquine (AS/AQ) as first-line therapy for the treatment of uncomplicated malaria, this study was designed to assess the treatment practices regarding anti-malarial drugs at health facilities in four rural areas in southern Cameroon.</p> <p>Methods</p> <p>Between April and August 2005, information was collected by interviewing fifty-two health professionals from twelve rural health facilities, using a structured questionnaire.</p> <p>Results</p> <p>In 2005, only three anti-malarial drugs were used in rural health facilities, including: amodiaquine, quinine and sulphadoxine-pyrimethamine. Only 2.0% of the health professionals prescribed the recommended AS/AQ combination. After reading the treatment guidelines, 75.0% were in favour of the treatment protocol with the following limitations: lack of paediatric formulations, high cost and large number of tablets per day. Up to 21.0% of professionals did not prescribe AS/AQ because of the level of adverse events attributed to the use of amodiaquine as monotherapy.</p> <p>Conclusion</p> <p>The present study indicates that AS/AQ was not available in the public health facilities at the time of the study, and health practitioners were not informed about the new treatment guidelines. Results of qualitative analysis suggest that prescribers should be involved as soon as possible in projects related to the optimization of treatment guidelines and comply with new drugs. Adapted formulations should be made available at the international level and implemented locally before new drugs and treatments are proposed through a national control programme. This baseline information will be useful to monitor progresses in the implementation of artemisinin-based combination therapy in Cameroon.</p

The virus in territory, between perceptions and measures

The handling of the health crisis resulting from the Covid19 pandemic has brought out the discrepancy between a centralizing State, in charge of its population’s safety, that in an emergency health situation applies uniform measures to the entire country, and a population whose everyday experience in its territory doesn’t necessarily reflect the same interpretation of the event and the logic behind the actions taken. We think that it might be interesting to consider the gap that may exist bet..

Processus migratoire et qualité de vie. L'exemple des migrants retournés au village dans une zone forestière du Sud Cameroun

International audienceFrom a survey conducted in a rural population of South Cameroon on the return to the village we wanted to know: who are the migrants and how big is the phenomenon of return to the village? - what are the reasons for the return and the means of reintegration of migrants in their village of origin? - what is their vision of the city and do they have new migration projects? - how do they speak about their quality of life in their migratory journey ? Our study concerns all the thirteen villages bordering the track ending the Ma'an - Ebolowa axis belonging to the geographical area of ​​the Ntem loop in South Cameroon. Fifty-two people were interviewed. The answers to these open questions, rich in information, were the subject of an analysis that allowed the construction of quantified variables. The results, supported by life stories and observations on the ground, made it possible to argue the questions previously asked. This analysis of "return migration" in a very low density equatorial forest area, the Ntem Loop, sheds light on one aspect of town-country relations by clearly denying the prejudices that forest areas are autarkic places of life without links with the outside world and in particular the urban centers. These areas also participate, and in a significant way, in the internal migration of Cameroon. "Return migration" is a relatively old phenomenon in this region; and even if it affects the villages differently, all participate in this population flow. Its recent development coincides with a qualitative transformation observed in other places, which results mainly from the more sensitive economic crisis in urban centers. Some major characteristics stand out, despite the heterogeneity of our body of work. Migrants enjoy a rather high level of education. They leave the village young and do not emigrate after thirty-five years. Their social status at the time of departure is very fragile since most of them are not married, do not have a plantation or a home of their own. No destination seems privileged (even if Gabon and Equatorial Guinea, countries nearby and sheltering the same ethnic group, represent attractive zones); however, three-quarters of migrants head for the city. The time spent outside the village is relatively long, but depends on the causes of return. If the return is mainly suffered (economic crisis, succession), this does not prevent a fairly rapid reintegration of migrants (marriage, creation of a plantation, even a box), especially since they never stopped maintaining relations with the village during their stay in the city. Their attitude towards a new beginning is a wait-and-see attitude (except for the youngest, who are also the least in the village), because it seems to them necessary to have a job to support the family. Nevertheless, the majority of the "return migrants" remain attracted to the city because, as one of them will tell us "... when you are in town, you are more dynamic, whereas in the village of It's not the same, it's routine, so I'd like to go back to town one day. "À partir d’une enquête réalisée dans une population rurale du Sud Cameroun sur le retour au village nous avons voulu savoir : qui sont les migrants et quelle est l’ampleur du phénomène de retour au village ? - quelles sont les raisons du retour et les modalités de réinsertion des migrants dans leur village d’origine ? - quelle est leur vision de la ville et ont-ils de nouveaux projets migratoires ? - comment parlent-ils de leur qualité de vie dans leur parcours migratoire ? Notre étude concerne l’ensemble des treize villages bordant la piste terminant l’axe Ma’an - Ebolowa appartenant à la zone géographique de la boucle du Ntem au Sud Cameroun. Cinquante-deux personnes ont été interrogées. Les réponses obtenues à ces questions ouvertes, d’un contenu riche en informations, ont fait l’objet d’une analyse qui a permis la construction de variables quantifiées. Les résultats, confortés par des récits de vie et des observations de terrain, ont permis d’argumenter les questions préalablement posées. Cette analyse de la “migration de retour” dans une zone de forêt équatoriale à densité très faible, la boucle du Ntem, permet d’éclairer un des aspects des rapports ville-campagne en démentant clairement les préjugés selon lesquels les zones de forêt seraient des lieux de vies autarciques sans liens avec l’extérieur et en particulier les centres urbains. Ces zones participent aussi, et de manière non négligeable, aux migrations internes du Cameroun. La “migration de retour” est un phénomène relativement ancien dans cette région ; et même si elle affecte diversement les villages, tous participent de ce flux de population. Son développement récent est concomitant d’une transformation qualitative observée en d’autres lieux, et qui résulte principalement de la crise économique plus sensible dans les centres urbains. Quelques grandes caractéristiques ressortent, malgré l’hétérogénéité de notre corpus. Les migrants jouissent d’un niveau d’étude plutôt élevé. Ils quittent jeunes le village et n’émigrent plus après trente-cinq ans. Leur statut social au moment du départ est très fragile puisque la plupart ne sont pas mariés, ne possèdent pas de plantation, ni d’habitation propre. Aucune destination ne semble privilégiée (même si le Gabon et la Guinée Équatoriale, pays tout proches et abritant la même ethnie, représentent des zones attractives) ; cependant, les trois quarts des migrants se dirigent vers la ville. Le temps passé à l’extérieur du village est relativement long, mais dépend toutefois des causes de retour. Si le retour est majoritairement subi (crise économique, succession), ceci n’empêche nullement une réinsertion assez rapide des migrants (mariage, création d’une plantation, voire d’une case), d’autant qu’ils n’ont jamais cessé d’entretenir des relations avec le village au cours de leur séjour en ville. Leur attitude vis-à-vis d’un nouveau départ est attentiste (sauf pour les plus jeunes, qui sont aussi les moins insérés au village), car il leur semble nécessaire d’avoir un emploi pour subvenir aux besoins de la famille. Malgré tout, la majorité des “migrants de retour” reste attirée par la ville car, comme nous le dira l’un d’entre eux “...quand vous êtes en ville, vous êtes plus dynamique, alors qu’au village c’est pas pareil, c’est la routine, alors j’aimerais rentrer un jour en ville”

Public perceptions and behaviours related to the risk of infection with Aedes mosquito-borne diseases: a cross-sectional study in Southeastern France

International audienceObjectives: To explore public perceptions and behaviours related to the risk of flavivirus and alphavirus infection in Southeastern regions of France following the recent colonisation of the Asian tiger mosquito, Aedes albopictus, and the identification of four autochthonous cases of dengue and chikungunya fever in these regions.Design: Cross-sectional telephone survey using a proportional random digit dialling selection method.Setting: Interviews were conducted from 28 November 2011 to 29 January 2012 using a computer-assisted telephone interviewing system. Participants: 1506 French speaking adults aged 18 years or older residing in French Mediterraneanregions.Results: Protective health behaviours were found to be performed less frequently among men (AOR=0.65, 95% CI 0.52% to 0.80%), residents with lower educational status (AOR=0.61, 95% CI0.43% to 0.85% for respondents with primary school education ; AOR=0.69, 95% CI 0.53% to 0.90% for those with some secondary school education), and those living in regions where the Aedes mosquito is objectively rare (AOR=0.60, 95% CI 0.36% to 0.98% for Aude; AOR=0.63, 95% CI 0.44% to 0.89% for Herault; AOR=0.56, 95% CI 0.34% to 0.93% for Eastern Pyrenees). Empirical results also suggest that behavioural responses to infection risk are greater shaped by the perceived exposure to Aedes, notably the perceived frequency of mosquito bites (AOR=2.07, 95% CI 1.84% to 2.32%) and visual identification of Aedes mosquitoes in one’s immediate environment (AOR=1.98, 95% CI 1.45% to 2.71%) rather than by other common predictors of protective behaviours.Conclusions : These findings may help with the development of innovative instruments designed tomake more visible and personal the threat of flavivirus and alphavirus infections induced by the presence of A albopictus in order to promote significant behavioural changes among populations at risk

Ducha modular portátil con filtrado de aguas grises

Ducha modular portátil con filtrado de aguas grises que cuenta con un sistema modular de recolección y filtrado que permite separar las suspensiones coloidales del agua en su base y que incluye por lo menos cuatro módulos. Primer módulo que se encarga de la recolección de aguas grises producto del aseo, la cual es tratada con agentes floculantes para lograr una coagulación y obtener su sedimentación, el agua tratada pasa a un módulo de filtrado primario donde un sistema de compartimientos de filtrado horizontal que contiene grava, arena y carbón activado filtra el agua la cual se es recolectada en un compartimiento inferior de almacenamiento. El agua filtrada almacenada en el módulo de filtrado primario es trasladada a un módulo de filtrado secundario, módulo que contiene filtros cerámicos, los cuales, tienen la capacidad de tratar aguas residuales y transformarlas en agua potable ya que estos filtros tienen la capacidad de atrapar partículas y microorganismos tóxicos mediante la filtración tortuosa, inhibiendo su reproducción con la aplicación de una capa de plata coloidal en su superficie. El agua tratada por los filtros cerámicos es conducida a un grifo de extracción de agua potable. El cuarto módulo es de almacenamiento de agua del filtrado primario, este módulo recoge el agua que rebalsa del filtro cerámico del módulo de filtrado secundario, esto es debido al tiempo que necesita el agua para atravesar el filtro secundario. El agua obtenida por el filtrado primario es utilizada para el aseo y es elevada a la ducha mediante un sistema de presurización para así volver al inicio del proces