venerdì 29 agosto 2014

Correlation is not causation

Correlation is not causation, as we often repat, but correlation is nonetheless always informative.

If you detect a correlation between A and B only three possibilities exist:


Only the first case is true correlation, but from the above graphic it is evident that also cases 2 and 3 allow to analyse the structure of data, once the factors C and D are discovered.

Case 2 is spurious correlation. But if you find C you have a model.

Case 3 is indirect correlation. In this case A and B are proxies or indicators of C and D, and can be used interchangeably. Often A and B are easier to measure than C and D.

It has been observed a drop in explanatory power in ecological studies in recent year. This is probably because we don't take into account the above very general patterns.

Structural Equation Models (SEM) allow to study the three cases, but unfortunately they can deal only with linear relationships.

mercoledì 27 agosto 2014

Ut pictura poesis

I always wonder at the abyss of my ignorance. I did not know the saying "ut pictura poesis" - famous at is can be. It is finely discussed in the english version of wikipedia. The idea has been widely criticized. In a previous post I reversed the statement, referring to contemporary art, and I don't know if it is more tenable in this form.

lunedì 25 agosto 2014

Milioni di voti per Berlusconi

Per anni è stato raccontato che la destra aveva dalla sua parte la maggioranza degli italiani. In realtà la destra (Berlusconi, AN e Lega) hanno ottenuto mediamente il 45% dei votanti, come si vede da questo grafico (che si riferisce alla Camera come i successivi)


Vedremo poi perché ho sottolineato dei votanti. Una prima considerazione: se avessimo mantenuto il proporzionale puro della prima repubblica avremmo avuto con tutta probabilità, uno stabile ventennio di coalizione tra centro e sinistra. In tutti questi anni il centro ha avuto sempre buone percentuali, e almeno in alcuni anni avrebbe potuto altalenare tra destra e sinistra, ma con un proporzionale probabilmente la scelta di una coalizione di centrosinistra sarebbe stata obbligata.

Se invece di considerare le percentuali dei votanti considerassimo la percentuale degli aventi diritto, vediamo che la destra ha avuto quasi costantemente il 36%, con valori minori nel '96 e 2008. Berlusconi in particolare ha sempre preso intorno ai 9 milioni di voti, corrispondenti al 20% circa dell'elettorato. Questo numero è simile alla percentuale dei redditi medio alti rispetto al totale della popolazione (ma in mancanza di altri dati questa potrebbe essere una coincidenza). Gli anni dopo il 1994 sono stati infatti anni di astensione piuttosto alta, specialmente le ultime in cui non ha votato circa 1/4 degli elettori, e questo comporta una grossa differenza tra percentuali dei votanti e degli aventi diritto, a differenza che nella prima repubblica dove le affluenze alle urne erano sempre molto alte. 




Il diagramma a torta (percentuali sugli aventi diritto) mostra che l'elettorato di destra è stato nettamente minoritario in Italia dopo il 1989. Si nota anche come destra + Grillo nel 2013 corrispondano a poco più (un 2% in più) del totale della destra del 2006 - cosa per altro più volte notata. Se si studia infine il grafico su wikipedia, si osserva come la destra corrisponda grosso modo esattamente ai voti di DC + liberali + MSI negli anni '70-80 e che sia rimasta grosso modo costante fino al 2013 (tranne che nel 1994 in cui c'è stato l'exploit della Lega).

In conclusione
  • con la legge elettorale che ha garantito quasi 50 anni di governo alla DC non avremmo avuto 20 anni di coalizioni di centrodestra ma (plausibilmente) 20 anni di coalizione di centrosinistra (che poi quella post-1989 sia veramente sinistra è da vedere, ma questo è un altro discorso)
  • Berlusconi, che ripeteva circa ogni 3 minuti di avere la maggioranza degli italiani, ha governato con poteri quasi assoluti per 20 anni con un consenso personale di circa 1/5 dell'elettorato, 9 milioni di voti su 48. Si potrebbe rispondere che sono sempre tanti, ma la differenza tra la percezione e la realtà è impressionante. La percezione è profondamente influenzata, infatti, dalla televisione.
Anche se i politici conoscevano benissimo questi numeri, ho scritto questo post solo ora, perché è completamente superato. La caduta (?) di Berlusconi e la nascita di un partito forte come quello di Grillo, la scomparsa probabilmente definitiva della sinistra radicale, la fusione (sembra)di quel che restava dei cattolici con il PD  hanno cambiato completamente la situazione politica, forse più radicalmente che nel 1994, credo più che per le nostre contingenze, perché la sovranità nazionale è passata ampiamente all'Europa.

Exit strategy

Walter Siti sembra aver preso la mia osservazione alla lettera. Sto leggendo "Exit Strategy" e mi sto scompisciando dalle risate. La cosa paradossale è che più le osservazioni sono vere, più fanno ridere. Non dovrei stupirmi. Essere seri, che ai tempi della borghesia eroica significava decoro e cultura, siginificava il puritanesimo borghese di Weber, - e anche il borghese avaro e cattivo ma dedito di Marx - oggi significa pensare e parlare solo di sesso figa privilegi - privilegi. non potere, perché il potere implica responsabilità e fatica: Il resto sono giochi o idealismo. Siti è quindi costretto all'ironia per parlare di cose che in fondo dovrebbero essere normalissime - invoca spesso la trascendenza, ma bello vero giusto autentico creativo puro sono cose materialissime.  Siti stesso aveva intuito,  in "Contagio", come il modello della borghesia stesse diventano il sottoproletariato. Però il sottoproletariato ha una purezza, che si perde nel passaggio alla piccola media e alta borghesia.

Feelings

I said that McEwans's novel "Enduring love" was illuminating. But it was illuminating in a dialectical way. In fact. not even a statement in the novel is true, and not even a feeling is deep. False conceptions and shallow felleing is the mark of middle class - but it is rarely so well described. Morevoer, if a false thesis is well presented. it is easy to find its anthitesis.

The main idea udnerlying the novel is that feelings and reason are at odd. This doesn't correspond to my experience. True skepticals are  wam and passionate - read the character of Socrates in Plato dialogues. And proletrians, thouth ardently passionate, are very clear-minded (see my previous post ). Although feelings can obscure reason (and reason repress feelings) there is no fundamanetal contradiction between the two, Only with a bad disposition of mind we can garble them. It is like right and left hand in knitting - the coordination is dificult and sometimes we make mistakes, but we don't claim that there is a fundamental contraditiction between left and right hand.

When I was a chid I often wondered "why feelings exist?" When I touch the fire I feel pain - but why? Why this long chain fire -> pain -> retreat? Would it not be simpler and faster fire->retrat? Thanks to the misunderstandings of McEwan I understood that we learn also with feelings. We learn through mental representations. These representations can be verbal, visual, and also made of feelings. Feeling representations are probably most primitive, and are present also in many animals, but for this very same reason they are also powerful and somtimes irreplaceable.

Enduring love

I have read McEwan's novel "enduring novel". I don't know if it is a great novel, but it is illumianting. Its core meaning is science and rationalism as religious (metaphysical) justification of the bourgeois way of life. I dare say that the meaning of my life - if life has a meaning - is that the burgeousis way of life and all the bourgeouis way of thinking are agains reaston. Today this means a rather solitary lfie, since we have married the bourgeois way of life with irraionalism.

I report an excerpt of the novel:

" We live in a mist of half-shared, unreliable perceptions, and our sense data come warped by a prims of desire and belief, which tilted out memories too. (...) Pityless objectivity, especially about ourselves was always a doomed social strtegy, We're descended from the passionate, indignant tellers of half truths  that in order to convince others, simultaneously convinced themselves. (...) This is why there re divorces, border diputes and wars, and this is why this statue ofthe Virgin weeps blood and that one of Ganesh drinks milk. And that was shy metaphysics and science were such curageous etrprises (..) huma artifacts set against the grain of human nature Disinterested truths".

This is a surprendent example of self-convinced half-truths: we ebguile ourselves, but is necessary very much beguilement to say that hat divorce from misunderstanding, and not from the fact that sometimes love ends, and that.wars arise self-deception and nio from conflicting interests. From this to say that our wars are disinterested truth ant the wars of other are due to ignorance - like in the Middle West today -  is just a small step further.



giovedì 21 agosto 2014

Scetticismo (II)

Dimenticavo una cosa fondamentale riguardo lo scetticismo. Spesso definiamo scettico chi dubita delle idee degli altri. Ma il vero scetticismo non è dubitare delle idee degli altri - che viene spontaneo - quanto dubitare delle idee proprie, e specialmente di quelle a cui siamo più affezionati. Anzi, lo scettico ribalta completamente l'atteggiamento naturale, e ha una posizione di attento ascolto e di disponibilità verso le idee degli altri, proprio perché un punto di vista diverso, magari anche sbagliato, può aiutare a mettere in discussione o nella migliore delle ipotesi a migliorare le proprie convinzioni - quelle da cui lo scettico diffida.

lunedì 18 agosto 2014

Scetticismo

Scetticismo non è dubitare di tutto, è lo stato mentale di sospensione di giudizio (epochè) ed è necessario al vero scienziato. E' molto vicino all'evangelico "non giudicate", che però si applica alle persone e non ai concetti, e richiede ugualmente intense energie spirituali. La piccola borghesia difficilmente raggiunge questo stato - il suo habitusi è quello del giudizio perenne - mentre è condizione standard nei proletari, che infatti sono, a modo loro, degli ottimi scienziati.

domenica 10 agosto 2014

Pasolini

Sono sempre piuttosto severo con Pasolini. Ma oltre che un profeta, era anche coraggiosissimo. La "Ricotta" fu subito ritirata dalle sale con l'accusa di vilipendio alla religione - un film spiritualissimo del quale Moravia disse "Molto più giusto sarebbe stato incolpare il regista di aver vilipeso i valori della piccola e media borghesia italiana," chiusa e cattiva ancor oggi, figuriamoci nel 1962.

Income inequality

I stumbled upon this post by Forbes. It would be funny if it were not tragic. In the end it says "When income and wealth inequality are growing, unease in our lives is shrinking". Of course "our lives" refers to the lives of billionaires, but  I remember that the years of highest income inequalities in the USA were 1929 and 2008, the years of collapse. Anyway, the problem is not that the rich says that his prosperity is the nation's prosperity. They always said so. The problem is that more and more poor people already believe the same.

Socialism, socialdemocracy, mixed economy

In the previous post I discussed the differences between socialdemocracy (Geramny, Sweden, Denmark) and mixed economy (Italy and Britain before 80s). The differences between them and with socialism can be phrased, anyway, in another way. In socialist economies, the lower classes take away all the wealth and property from the upper classes; in socialdemocracy lower classes take away part but not all of the property, in mixed economies the lower classes do not take anything from the upper classes, but develop a parallel, state-owned economy side by side with the free enterprise. Put in this way, mixed economies - such as that of Italy before 1989 - are far from socialism and vey close instead to liberal economies. It is therefore not suprising that the transition to fully liberist models happened so rapidly, in the 802 in Britain and ten years later in Italy.

sabato 9 agosto 2014

Socialdemocracy and mixed economy

In Italy, and probably in other countries, the prestige of Germany is steadily rising. This is not surprising. Given the very good performances of this country in a period of heavy global depression. Nonetheless, I see that the economic model of Germany and other socialdemocracies is poorly understood. The “social model” of Europe – a “third way” between the pure liberism of the United States and the socialism of Soviet Union – had in fact two very different declensions: the socialdemocracy of Central Europe, and the mixed economy of Britain, Italy and partly France. Many believe that Italy has been fundamentally a socialist country, modelled after the Soviet Union, but our model was rather Britain and its mixed economy. The sanitary service, for instance, is cleary shaped after the British Sanitary Service.
Both socialdemocracies and mixed economies envisage strong state intervention in economy, but in a very different way. In socialdemocracies enterprise is almost exclusively private, but there is a strong, progressive taxation that redistribute wealth from the rich to the poor via a very developed network of universal social services. In mixed economies there are state enterprises that coexist with private enterprises and often represent a consistent fraction of national economy. In Italy the publicly hold IRI represented the largest enterprise in the country, but coexisted with other big corporations such as FIAT or Ansaldo. In Britain the fraction of publicly hold enterprises was perhaps even bigger. In mixed economies taxation is relatively low and not strongly progressive, and social services are present but less developed than in socialdemocracies. Somebody could say that taxation is Italy is very high, but, although in principle it is strongly progressive, in practice taxes are paid almost exclusively by the lower classes, given the existence of extensive fiscal evasion in the upper classes.
Today socialdemocracies not only survive but show very good economic performances. Mixed economies, with the exception of France, have disappeared: public enterprises have been sold and Britain and Italy have changed from a mixed socialist/liberist model, to an almost completely liberist economic model with a relatively well developed welfare (the persistence of a welfare system today is the main difference with USA). In Britain the transition to a liberist model happened in the early 80’s, while in Italy it is more recent and successive to the collapse of the Soviet Union.
It must be said that Prodi and Bersani had in mind to follow a German model and to transform Italy into a socialdemocracy, but their project failed largely because of the opposition of PD. The majority of former communist party in fact converted to liberism after 1989, and never considered the possibility of a socialdemocratic model, largely, I suspect, because of poor knowledge of the redistributive model of Central European economies. In Italy, before 1989, we had a conflict between socialism and liberism, and few knew exactly what happened in Sweden, Germany, Denmark.



mercoledì 6 agosto 2014

Me and us

Ian Mcwan writes "This is our mammalian conflict - what to give to the others and what to keep for yourself. Treading that line (..) is what we call morality. (..) our crew enacted morality's ancient, irresorvable dilemma us, or me." All this seems self evident, and fundamental to all societies, and yet the reasoning is irremediably flawed. "Us", in effect, does not exist; it is the collection of a number of singularity, few in small societies or in a family, many in large societies. And the resolvable conflict is not between me and a non-existant us (an abstract us), but between individuals with theyr legitimately conflicting itnerests. Law is an attempt at regulating these ever-changing and evolving relationships. and morality is personal law. Selfishness often (but not always) does not allow conflicts to be resolved, and this is the base for the importance we put on altruism. But commercial conctracts, for instance, are perfectly compatible with selfishness and indeed such contracts, based on not-altruistic feelings, can contribute much to the well-being of the society.

Margareth Thatcher said that society - us - does not exist. She was right, since ther is not a social body resulting from the collection of individuals, and she was wrong, since relationships do exist.

Anyway, there are circumstances wehre it is natural to use the pronoun us. For instance, supporters of a football team usually say "us" when referring to the team - even if they are only supporters, not actual players. "us" is used always in contrast to "them". Collectivity is a collection of relationship, "us" is a super-individual body that springs when it is necessray to fight an enemy. Self-sacrifice is rarely necessary in peace and in ordinary relationships, it is instead unavoidable in war, be it the war against another nation, another class, or (in the case of Christianism), against the Evil.