Mai Thi Nguyen-Kim – laut dem Kommunikationsdienst der Medienbranche Turi2 Deutschlands bekannteste Wissenschaftsjournalistin – brachte in der Vergangenheit immer wieder spannende Videos. Allerdings hat sie sich bei dem Thema Genetik überhoben und ist offensichtlich auch nicht gut in der Wissenschaftsszene vernetzt. Anders sind ihre Aussagen zur Genetik jedenfalls nicht zu erklären.
Ihr Zweifel an dem Rassenbegriff ist ja völlig berechtigt, denn nur Rassisten reden von Rassen. Wir reden schon lange nicht mehr von Rassen bei Menschen, sondern von Populationen, Volksgruppen, Ethnien oder was auch immer (Rassen sind ansonsten die gezielt gezüchtete Tier- oder Pflanzenarten, die sich durch Selektion auf bestimmte Eigenschaften vermehrt haben). Wir reden deshalb nicht mehr davon, weil die Anfang des letzten Jahrhunderts von Anthropologen beschriebenen äusseren Merkmale von Menschen eben nicht mit den Ergebnissen der modernen Genetik überein stimmen. Aber statt dann wenigstens bei dem Thema Populationsgenetik in ihrem Video zu bleiben, zieht sie auch noch eine direkte Linie zum Kolonialismus. Und stellt dann auch noch eine Verbindung zur Kriminalstatistik her. Das ist unseriös und nur der Aufmerksamkeitsökonomie geschuldet.. Continue reading Die unangenehme Wahrheit des Mai Thi Videos→
Having been confronted with the “pull” doctrine now many times, I went for further literature. The best summary that I have found is by the European Asylum Support Office 2016
On the conceptual level, there are serious limitations with the commonly used (yet often critiqued) push and pull framework as an explanatory tool for migration decision-making processes … it makes strong assumptions about the way individuals respond to stimuli; it presumes that an individual can make cost/benefit decisions based on full information, in markets tending to a general equilibrium, far from the complex reality of human mobility. As such, the model fails to explain why, for instance, people respond differently to the same ‘push’ and ‘pull’ forces, and why emigration and immigration occur simultaneously in the same area.
There seem to be many more limitations than currently assumed.
factors explaining migration 1) often originate in the household/community/country of origin (e.g. unemployment, gender discrimination, conflict), while factors influencing migration 2) are more likely to be destination-specific (e.g. presence of co-ethnic community members, perception of the country as having a permissive asylum regime, language similarities) or process- specific (e.g. a smuggler has chosen a destination).
Another key issue, is the high death toll that is of course known to refugees.
Studying migration flows across the Mediterranean, particularly along two routes (the western and central Mediterranean routes), Altai Consulting found that social, political, and economic instability inspired migration flows but that individuals fleeing greater threats to their personal security were willing to traverse more dangerous and uncertain migration routes.
So we are dealing with
Socio-economic factors
Political factors
Demographic factors
Historical, cultural and geographic factors
Environmental factors
Migration policy factors
Economic factors in the asylum destination choice
Summary of convergence/divergence trends
The report shows the relevance of migrant networks in facilitating asylum migration movements and influencing migrants’ destination choices. Going back even to an earlier report of migration direction in Science, I can’t find any evidence for any pull effect.
Guy J. Abel and Nikola Sander. Quantifying Global International Migration Flows. Science 2014; 343:6178
Aug 4, 2023
There is a new time series study in Sci Rep by Alejandra Rodríguez Sánchez aggregating counts of arrivals, pushbacks, and deaths adjusting for various known drivers of irregular migration via the Central Mediterranean Route
A comparison of the observed and predicted counterfactual time-series in the post-intervention periods suggest that pushback policies did affect the migration flow, but that the search-and-rescue periods did not yield a discernible difference between the observed and the predicted counterfactual number of crossing attempts.
Unfortunately most studies in the farming environment do not report the prevalence of parental history. Neither did they report the effect size of parental genetic risk in the farming population. This is, however, a critical issue as the so called healthy worker effect (HEW) may be a rather trivial explanation of the results.
Specifically, it is a sampling bias: the kind of subjects that voluntarily enroll in a clinical trial and actually follow the experimental regimen are not representative of the general population. They can be expected, on average, to be healthier as they are concerned for their health [or as ill people already dropped out]
Leynaert 2001 showed only a slightly reduced prevalence of “allergy” (39.1% vs 41.5%, NS). Her table 4 is most interesting. The association started only after year 1960 which points towards severe misclassification as far as the analysis is not stratified by year of birth.
Remes 2002 showed a dose dependent effect decline between farming (36.2%) and controls (31.6%, P=0.075),
Perkin 2006 also found some significant lower prevalence in farmers 47.3% versus 57.7%, P<0.001. HWE is therefore likely.
I found further six studies (Thelin 1994, Braback 2006, Chenard 2007, Thaon 2011, Elholm 2013 and Spierenburg 2015) that examined in detail a possible relationship of HWE, allergy and farming. Unfortunately the examination period in five of these studies is too short to make any conclusion while Braback 2006 seems to be the only reliable study.
From this study, we can safely conclude, that there is a significant HWE.
Addendum 22 Nov 2019
It seems that I missed some papers on HWE and farming.
Timm 2019 is a hard to understand cluttered 3 generation study of unclear asthma type. Point estimates of parental asthma on farm upbringing are not really a measure of HWE – shuffling exposure and outcome distorts temporality. In contrast to the interpretation of the authors, I see a clear effect if both parents are born on a farm and one parent has asthma. The RR drops here to 0.33 that their child will be raised on a farm.
Vogelzang 1999: 400 pig farmers, X-sectional point estimates, not a real HWE study, although HWE offered as explanation.
Health-based selection of nonasthmatics for pig farming, which tends to mask a work-related hazard for asthma, is offered as an explanation for these results.
Eduard 2015: compares asthma prevalence of 313 Danish farm children to their 518 sibs (which is identical) but useless, as affected parents would basically dropout all children.
There is even a second comparison of Norwegian farmers with a clear effect. Instead of comparing the early retired farmers with their respective age cohort they invented a c complicated quantile logitic regression in 4 year intervals. Detailed model parameter and significance levels are missing.
At least the conclusion was
A healthy survivor selection was observed in Norwegian farmers, but it was too small to fully explain the reduced risk of asthma observed in this population. A strong selection effect was observed among farmers who had changed production type
