state of the [des]Union

abortion in Québec

day one at ISBA 22

Started the day with a much appreciated swimming practice in the [alas warm⁺⁺⁺] outdoor 50m pool on the Island with no one but me in the slooow lane. And had my first ride with the biXi system, surprised at having to queue behind other bikes at red lights! More significantly, it was a great feeling to reunite at last with so many friends I had not met for more than two years!!!

My friend Adrian Raftery gave the very first plenary lecture on his work on the Bayesian approach to long-term population projections, which was recently  a work censored by some US States, then counter-censored by the Supreme Court [too busy to kill Roe v. Wade!]. Great to see the use of Bayesian methods validated by the UN Population Division [with at least one branch of the UN

Stephen Lauritzen returning to de Finetti notion of a model as something not real or true at all, back to exchangeability. Making me wonder when exchangeability is more than a convenient assumption leading to the Hewitt-Savage theorem. And sufficiency. I mean, without falling into a Keynesian fallacy, each point of the sample has unique specificities that cannot be taken into account in an exchangeable model. Nice to hear some measure theory, though!!! Plus a comment on the median never being sufficient, recouping an older (and presumably not original) point of mine. Stephen’s (or Fisher’s?) argument being that the median cannot be recursively computed!

Antonietta Mira and I had our ABC session this afternoon with Cecilia Viscardi, Sirio Legramanti, and Massimiliano Tamborino (Warwick) as speakers. Cecilia linked ABC with normalising flows, in collaboration with Dennis Prangle (whose earlier paper on this connection was presented as the first One World ABC seminar). Thus using past simulations to approximate the posterior by a neural network, possibly with a significant increase in computing time when compared with more rudimentary SMC-ABC methods in larger dimensions. Sirio considered summary-free ABC based on discrepancies like Rademacher complexity. Which more or less contains MMD, Kullback-Leibler, Wasserstein and more, although it seems to be dependent on the parameterisation of the observations. An interesting opening at the end was that this approach could apply to non iid settings. Massi presented a paper coauthored with Umberto that had just been arXived. On sequential ABC with a dependence on the summary statistic (hence guided). Further bringing copulas into the game, although this forces another choice [for the marginals] in the method.

Tamara Broderick talked about a puzzling leverage effect of some observations in economic studies where a tiny portion of individuals may modify the significance or the sign of a coefficient, for which I cannot tell whether the data or the reliance on statistical significance are to blame. Robert Kohn presented mixture-of-Gaussian copulas [not to be confused with mixture of Gaussian-copulas!] and Nancy Reid concluded my first [and somewhat exhausting!] day at ISBA with a BFF talk on the different statistical paradigms take on confidence (for which the notion of calibration seems to remain frequentist).

Side comments: First, most people in the conference are wearing masks, which is great! Also, I find it hard to read slides from the screen, which I presume is an age issue (?!) Even more aside, I had Korean lunch in a place that refused to serve me a glass of water, which I find amazing.

¡cuida tu vestido y no hables tanto, Jorge!

“I have no way of telling whether [Putin’s] rage has been provoked»” Bergoglio wonders, «but I suspect it was maybe facilitated by the West’s attitude” [“Un’ira che non so dire se sia stata provocata — si interroga —, ma facilitata forse sì”]

“I don’t know if it is the right thing to supply the Ukrainian fighters” [” all’interrogativo se sia giusto rifornire gli ucraini”]

“What seems indisputable is that in that country both sides are trying out new weapons. [” La cosa chiara è che in quella terra si stanno provando le armi.” Corriere Della Sera, 22 Maggio 2022]

“This is a historic day in the life of our country, one that stirs our thoughts, emotions and prayers. For nearly fifty years, America has enforced an unjust law that has permitted some to decide whether others can live or die; this policy has resulted in the deaths [sic] of tens of millions of preborn children, generations that were denied the right to even be born (…) We thank God today that the Court has now overturned this decision.” U.S. Conference of Catholic Bishops, 24 June 2022

a forecasted end to Roe v. Wade

“After today, young women will come of age with fewer rights than their mothers and grandmothers had. The majority [of the Supreme Court] accomplishes that result without so much as considering how women have relied on the right to choose or what it means to take that right away. The majority’s refusal even to consider the life-altering consequences of reversing Roe and Casey is a stunning indictment of its decision (…) Now a new and bare majority of this court – acting at practically the first moment possible – overrules Roe and Casey. It converts a series of dissenting opinions expressing antipathy toward Roe and Casey into a decision greenlighting even total abortion bans. It eliminates a 50-year-old constitutional right that safeguards women’s freedom and equal station. It breaches a core rule-of-law principle, designed to promote constancy in the law. In doing all of that, it places in jeopardy other rights, from contraception to same-sex intimacy and marriage. And finally, it undermines the court’s legitimacy.”  Stephen Breyer, Sonia Sotomayor and Elena Kagan, June 24, 2022

“Judge Thomas noted that in its rationale, the court’s majority found that a right to abortion was not a form of “liberty” protected by the due process clause of the 14th Amendment to the Constitution — as the court had said in Roe. Then, he took aim at three other landmark cases that relied on that same legal reasoning: Griswold v. Connecticut, a 1965 decision that declared married couples had a right to contraception; Lawrence v. Texas, a 2003 case invalidating sodomy laws and making same-sex sexual activity legal across the country; and Obergefell v. Hodges, the 2015 case establishing the right of gay couples to marry.” The New York Times, June 24, 2022