Archive for Nature

postdoc shortage

Posted in Books, pictures, Statistics, Travel, University life with tags , , , , , , , , , on October 4, 2022 by xi'an

An interesting tribune in Nature (30 August) about the difficulty in hiring postdocs… I myself faced this difficulty in the recent years but though it was mostly due to unattractive French salaries and working conditions, or COVID issues (or myself!). Nature mentions politics, economics, ethics, and personal priorities as main reasons for the postdoctoral drought. In Britain, Brexit is definitely a central factor as candidates face enormous bills to secure entry to the United Kingdom (as Hai-Dang Dau, now in Oxford, was explaining to us after his successful PhD defense at ENSAE-CREST this morning). But more globally this may reflect a general exodus from academia towards company jobs, and their much more attractive salaries. Especially in STEM where Amazon and buddies created a new definition of “dream jobs”… Anyway,  I still have a prAirie postdoc position open in Paris Dauphine and the new PariSanté campus provides a great working environment, so feel free to contact me!

probability model for credits

Posted in pictures, University life with tags , , , , on September 13, 2022 by xi'an

A recent article in Nature examines the gender imbalance in scientific authorship, by building a probability model of how likely women are to fail being associated with the authorship of a scientific paper to which they contributed. I did not read the paper in detail (while on a train) and thus cannot comment about the scientific basis of the model but am surprised at the specific case of Mathematics, where the 50% share in the above graph seems to conflict with the strong (and sad) gender imbalance in the current faculty composition for the field. The analysis is based on US data from (a) a self-reporting survey, (b) administrative data,  where records are available about “every payment that is made during each pay period from each grant and provide information on each employee’s job title”, which only covers US research work covered by grant money, and (c) percentage of women against paper citation index. For (b), it is unclear to me who would qualify as research staff in a theoretical math research project.

toilet issues [infographics]

Posted in Books, pictures, Travel with tags , , , , , , , , on August 25, 2022 by xi'an

As Western Europe is currently gasping under the worst drought in 500 years (?), a few sentences heard on the French public radio, about domestic grey water double-usage, as well as an email from>Nature about the above infographics winning a prize this year, made me re-ponder about the unsustainable way flush toilets process human waste, from wasting insane amounts of drinkable water to requiring energy-greedy processing plants. Not to mention the wipes-induced fatbergs. The above is one of several urine diversion toilets that divert it from the solids and, provided it is processed properly, turn it into a high quality fertilizer. Maybe the current water crisis will push towards new waste management policies, more sustainable.

In the same article, the attitude towards food grown with human fertilizers was shown as highest in France and at first I thought this was unsurprising given that wastewater here was recycled into the water cycle, but this is not at all the case. Only 1% is reused for irrigation (or wasted, since it is for golf courses!).

efficient measures?

Posted in Books, Statistics, University life with tags , , , , , , , , , on July 24, 2022 by xi'an

When checking the infographics of the week highlighted by Nature, I came across this comparison of France and Germany for the impact of their respective vaccination mandates on health and economics. And then realised this was from a preprint from a Paris Dauphine colleague, Miquel Oliu-Barton (and co-authors). The above graphs compare the impact of governmental measures towards vaccination, short of compulsory vaccination (unfortunately).  Between Germany and France, it appears as if the measures were more effective in the latter. Which may be interpreted as either a consequence of the measures being more coercive in [unruly] France or an illustration of the higher discipline of the German society [despite the government contemplating compulsory vaccination for a while]. As an aside, I am very surprised at the higher death rate in Germany but, beside a larger percentage of people over 65 there and a lower life expectancy, the French curve is interrupted in December 2021. Looking at 2022, the peak was reached at 3.3 cases per day per million people.

Concerning the red counterfactual curves, I did not find much explanation in the preprint, apart from

“Our results are supported by the well-established econometric method of synthetic control.³⁰ We construct counterfactuals for each treated country based on a weighted average of countries that did not implement the COVID certificate and find consistent trajectories for the time period where this method is feasible, i.e., until the end of September 2021.”


“constructing counterfactuals ( i.e., by modelling vaccine uptake without this intervention), using innovation diffusion theory.⁶Innovation diffusion theory was introduced to model how new ideas and technologies spread”

which is not particularly helpful without further reading.

easy does it?! [fuel crisis]

Posted in Statistics with tags , , , , , , , , on July 9, 2022 by xi'an

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