Archive for February 2013

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What schools don't teach..


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Cosa dovremmo imparare a scuola? Solo nozioni, formule e descrizioni?
L'informatica "insegna" a pensare, a creare, a costruire.. ad usare la fantasia. Non serve ricordare centinaia di pagine ma basta pensare e inventare.. e la strada del successo diventa tutta in discesa!

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Segnali e cause


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"It turns out that people who use Firefox are more likely to engage in certain online activities than those that use IE. And it turns out that people who eat before bed are believed to gain more weight than those that don't. Perhaps using Firefox makes you a different sort of surfer, or the timing of the calories has something to do with your metabilism. More likely: the sort of person who takes the time to install a new browser is precisely the kind of person willing to use a new web service. The kind of person who makes a habit out of eating when bored (just before bed) might very well be the kind of person that has to wrestle with weight.

We see the same thing in outbound marketing. Spammers in Nigeria continue to use poorly written, ridiculous pitches. Not because they cause people to give up their senses and send tens of thousands of dollars, but because the kind of person that falls for something so dumb is probably the kind of person who is also going to be easily scammed. [...] A fever might be the symptom of a disease, but artificially lowering the fever (ice bath, anyone?) isn't going to do anything at all to change the illness.

Before changing the signal and thus assuming that this will change the outlook, it probably makes sense to understand what will change the causes of someone's perception and habits, and use the signal as a way of figuring out who needs to be taught."
Tratto da  Seth's blog

Molto interessante e molto attuale, specialmente in tempo di elezioni.

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This is.. real!


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Amazing. And real. Viviamo davvero in un mondo fantastico.

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Blue-eyed Monks


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Problem 
There is an island inhabited by monks who are very intelligent but have some very rigid rules that they live by.  For one, they believe that blue eyes are evil and if a monk finds out she has blue eyes she must kill herself *that very day*.  Another rule is that, despite everyone seeing each other every day, they cannot communicate in any way whatsoever. That, combined with the fact that there are no reflective surfaces on the island, means that the blue-eyed monks never find out their eye color and so all is good for years and years.  But one day a visitor comes to the island and before they leave, remarks for all to hear that they've never seen such beautiful blue eyes as on this island.

Assumptions
  • Every monk sees every other monk all the time
  • It is common knowledge on the island that all monks are rational and obey all monk protocols perfectly
  • Monks reason instantly and if one concludes that she has blue eyes she will commit suicide by sunset of that day
  • The visitor's announcement is made publicly
  • The visitor adds nothing but that observation (that there exist blue eyes on the island)

What happens? 

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Conjecture
If there are n blue-eyed monks on the island, they will all commit suicide on the nth day.  

Proof 
By induction on n.
Base Case: If there is only 1 blue-eyed monk, the visitor's announcement will prompt that monk's suicide the same day, day 1.
General Case: Assume that with n blue-eyed monks on the island, they will each commit suicide on day n.  Prove that with n+1 monks on the island, they will each die on day n+1.  This is true because if there are n+1 blue-eyed monks then each of them will *observe* n blue-eyed monks. Thus, by the induction hypothesis, they will expect (hope) that the n monks they observe will all commit suicide on day n.  When this doesn't happen, the only explanation can be that there are *not* in fact n blue-eyed monks.  There must be an additional, unseen, pair of blue eyes -- their own.  All following identical reasoning, they each realize their fateful eye color at the end of the nth day, and on day n+1 they each commit suicide. 

Example 
Suppose there are 2 blue-eyed monks on the island and you're one of them. Before the visitor arrives you always assume that the blue-eyed monk you observe is the only monk with blue eyes -- ie, you're safe.  (That monk is of course thinking the same thing about you). When the visitor announces that there are blue eyes on the island you expect the *one* (so you think) blue-eyed monk to commit suicide. When they don't, you realize you're in trouble.  They must have been watching someone else and waiting for that person to commit suicide.  
The only person that they could have been watching is you -- you can see that everyone else on the island has brown eyes so that rules them out.  So because the other blue-eyed monk didn't kill herself on day 1, you deduce on day 2 that your eyes are blue and you kill yourself.  The other monk went through identical reasoning watching you and so will also commit suicide on day 2.  Supposing there are 3 blue-eyed monks, each is watching the other 2 and expecting, by the reasoning above, that they will both die on day 2.  When they don't, she concludes that they must not be watching just each other.  Since it's symmetric, the other 2 monks are each watching you and the other one and thinking the same thing.  Hence, you all 3 know to kill yourselves by the 3rd day.  etc... 
It's clear that the visitor was necessary in the proof in order to establish the base case.  However, the only information that the visitor provides (there exist blue eyes on this island) is something that (assuming more than 1 blue-eyed monk) every single monk already knew.  

Question 
What was different after the visitor's announcement? Ie, as a monk on the island, what do you know after the visitor's announcement that you didn't know before?

Taken from: Daniel Reeves

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Never trust women


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Fantastico. Lei è fantastica.. Never trust women.

Questo è un classico esempio di "Game Theory". La scelta di ognuno dipende dal comportamento degli altri, e si finisce in gabbia. Una via d'uscita è la fiducia, ma non sempre funziona (vedi sopra..!).

Cosa farei io?
Lascerei parlare lei, poi direi: "Io non mi fido di te. Io scelgo "steal", indipendentemente da quello che dirai o farai tu. Ora, se anche tu scegli "steal" perdiamo entrambi; se invece scegli "split" io vinco e tu non ottieni nulla. Ma siccome mi hai fatto vincere, posso darti una parte della vincita. Diciamo 25.000 dollari."

Ovviamente rischierei, ma di certo preferisco avere la situazione in mano e rischiare, piuttosto che lasciare tutto nelle mani dell'altro e dipendere totalmente dalle sue decisioni. Lei non avrebbe scampo: scegliere "steal" sarebbe inutile, tanto vale arrendersi a "split" e sperare che io sia clemente. Questa strategia si chiama "contratto", e di fatto si tratta proprio di un accordo: la ragazza potrebbe accettare la proposta e magari negoziare la sua quota..

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Propaganda (in)utile


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Poco fa mi arriva questa simpatica mail:

"Gentili tutt@,
trasmetto il mio materiale elettorale .
Scusandomi per l'intrusione porgo cordiali saluti.

Informativa ai sensi dell’art 13 del D.Lgs 196/2003
I dati da Lei forniti liberamente, raccolti in manifestazioni pubbliche oppure estratti da elenchi pubblici sono utilizzati da [...] solo ed esclusivamente ai fini di propaganda elettorale del candidato e non saranno comunicati a terzi. Lei ha diritto, in qualunque momento, di accedere ai dati, ottenere di non ricevere più materiale di propaganda, opporsi al trattamento dei dati o chiedere di integrarli,rettificarli, aggiornarli  inviando una e-mail [...]"

Ovviamente il mettente è un "politico" a me sconosciuto, a cui non ho mai dato la mia mail e che ha pensato di fare un po' di propaganda in vista delle elezioni. Probabilmente il mio indirizzo l'ha preso da qualche mia adesione online a scuole/corsi/newsletter o simili, quindi non posso biasimarlo (anche se in realtà non penso di aver mai autorizzato l'utilizzo "pubblico" della mia mail), in ogni caso leggo volentieri gli allegati perché può essere utile ad approfondire la mia conoscenza dei candidati.

Ebbene apro i due file pdf e trovo una lettera di poche righe, che in sostanza dice "votatemi", e un volantino che rappresenta come votarlo e dove scrivere il suo cognome. Nulla di più, non una parola su chi è e cosa vuole fare di bello per noi, non un riferimento ai temi dei quali si vuole occupare, alle sue competenze e alle sue proposte. 

Allora rispondo alla mail:

"Buongiorno
Grazie per la comunicazione (anche se in realtà non l’ho mai chiesta, comunque mi piace dare uno sguardo a tutto)
 
Mi permetto solo di dirle che da un candidato politico io generalmente mi aspetto CV, futuro programma politico dettagliato (personale) e breve riepilogo dell’attività (politica e sociale) svolta finora. Poi penserò io a come votare e cosa scrivere sulla scheda.
 
Vedo che sul suo sito parte del materiale è disponibile, ma credo manchi un programma personale (almeno una dichiarazione di intenti). Anche perché se ci si affidasse solo al programma dei “grandi partiti”, allora non ci sarebbe differenza tra un candidato e l’altro.
 
Mi scusi l’intrusione"

Beh mi sembra il minimo, no? 
Poco dopo replica ringraziandomi per l'osservazione, ma dimenticandosi di allegare CV, programma e riassunto dell'attività svolta finora. Una svista?
 

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Nash's idea?


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[...] Mr. Nash's contribution was far more important than the somewhat contrived analysis about whether or not to approach the most beautiful woman in the bar. What he discovered was a way to predict the outcome of virtually any kind of strategic interaction. Today, the idea of a ''Nash equilibrium'' is a central concept in game theory.

Modern game theory was developed by the great mathematician John von Neumann in the mid-1940's. His goal was to understand the general logic of strategic interaction, from military battles to price wars. Von Neumann, working with the economist Oscar Morgenstern, established a general way to represent games mathematically and offered a systematic treatment of games in which the players' interests were diametrically opposed. Games of this sort -- zero-sum games -- are common in sporting events and parlor games.

But most games of interest to economists are non-zero sum. When one person engages in voluntary trade with another, both are typically made better off. Although von Neumann and Morgenstern tried to analyze games of this sort, their analysis was not as satisfactory as that of the zero-sum games. Furthermore, the tools they used to analyze these two classes of games were completely different. Mr. Nash came up with a much better way to look at non-zero-sum games. His method also had the advantage that it was equivalent to the von Neumann-Morgenstern analysis if the game happened to be zero sum.

What Mr. Nash recognized was that in any sort of strategic interaction, the best choice for any single player depends critically on his beliefs about what the other players might do. Mr. Nash proposed that we look for outcomes in which each player is making an optimal choice, given the choices the other players are making. This is what is now known as a Nash equilibrium. At a Nash equilibrium, it is reasonable for each player to believe that all other players are playing optimally - since these beliefs are actually confirmed by the choices each player makes. 

It's a nice theory. But is it true? Does it describe actual behavior in actual games? Well, no. Game theory is an idealization: it analyzes how ''fully rational'' players should play if they all know they are playing against other fully rational players. That assumption of ''full rationality'' is the problem with game theory. In real life, most people - even economists - are not fully rational.

Consider a simple example: several players are each asked to pick a number ranging from zero to 100. The player who comes closest to the number that is half the average of what everyone else says wins a prize. Before you read further, think about what number you would choose. Now consider the game theorist's analysis. If everyone is equally rational, everyone should pick the same number. But there is only one number that is equal to half of itself: zero. This analysis is logical, but it isn't a good description of how real people behave when they play this game: almost no one chooses zero. 

But it's not as if the Nash equilibrium never works. Sometimes it works quite well. Two economists, Jacob Goeree and Charles Holt, recently published a clever article, ''Ten Little Treasures of Game Theory and Ten Intuitive Contradictions,'' that exhibits a number of games in which the Nash theory works well, and then show that what should be an inconsequential change to the payoffs can result in a large change in behavior. In their simplest example, two players, whom we will call Jacob and Charles, independently and simultaneously choose an amount from 180 cents to 300 cents. Both players are paid the lower of the two amounts, and some amount R (greater than 1) is transferred from the player who chooses the larger amount to the player who chooses the smaller one. If they both pick the same number, they both are paid that amount, but no transfer is made. So if Jacob chooses 200 and Charles chooses 220, the payoff to Jacob is 200+R and the payoff to Charles is 200-R. If Jacob thinks Charles will say 200, then Jacob will want to announce 199. But if Charles thinks Jacob will announce 199, then Charles should say 198. And so on. The only consistent pair of beliefs is when each thinks the other will say 180. When Mr. Goeree and Mr. Holt performed this experiment with R=180, nearly 80 percent of the subjects picked 180, which is the Nash prediction. When they set R=5, and reran the experiment (with different subjects), however, the outcomes were completely reversed, with nearly 80 percent choosing 300.

Findings of this sort have stimulated the development of ''behavioral game theory'', which tries to formulate a theory of how to understand games involving real people, rather than those mythical ''fully rational'' people. Consider, for example, the ''guess half the average'' game described earlier. Oscar, a simpleminded player, might think that any number between zero and 100 is equally likely, so he would guess 50. Emmy, who is more sophisticated, might figure that if lots of people were like Oscar and say 50, then she should say 25. Tony, who is yet more sophisticated, figures that if lots of people think like Emmy, then he should say 12 or 13. And so on. An economist named Rosmarie Nagel ran a game like this a few years ago and found that the choices do tend to cluster around 50, 25 and 12. In fact, the winning choice turned out to be close to 13, a number chosen by about 30 percent of the players. In this game the best strategy wasn't the Nash equilibrium, but it wasn't so far away from it either.

Back to picking up women. In the movie, the fictional John Nash described a strategy for his male drinking buddies, but didn't look at the game from the woman's perspective, a mistake no game theorist would ever make. A female economist I know once told me that when men tried to pick her up, the first question she asked was: ''Are you a turkey?'' She usually got one of three answers: ''Yes,'' ''No,'' and ''Gobble-gobble.'' She said the last group was the most interesting by far. Go figure.

Thansk to H. R. Varian

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Insieme.


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[...] È che volevo dirti questo. E siccome mi fa paura non voglio che tu mi senta. Ce la faremo. Io e te. Sì. Ce la faremo. O forse no. Forse a un certo punto un oroscopo sfavorevole ti metterà in guardia dal leone. Ma noi ci ameremo. Io e te. O forse a un certo punto smetteremo di amarci, perché tanto poi tutto finisce, le incomprensioni, le parole di troppo e quelle non dette. Staremo sempre insieme. O forse no, perché io farò un Erasmus in Lettonia e non potrai certo aspettarmi sei mesi o tu all'improvviso andrai in India per cercare te stessa o un lavoro. 

Avremo cura di noi. O forse no. Tu penserai che sono il solito maschio che si lamenta, che appena ha due linee di febbre cerca in internet il numero di Umberto Veronesi. Io e te. Avremo dei figli. O forse no, perché altrimenti ti licenziano, senza sette ore di sonno impazzisco, e poi non senti in giro quante coppie che fanno fatica ad averne? E andremo a vivere insieme. Forse. Perché sai che la mia iguana si spaventa, e non è che tutte le sere posso vedere «Grey’s Anatomy» e quel cane che muore mi fa piangere e poi — lo sai — mia madre cucina il miglior baccalà del mondo. Faremo fatica, ma troveremo un senso anche nella fatica. O forse no. Da un giorno all’altro tutto ci sembrerà inutile, ci lasceremo e ci sembrerà assurdo aver rinunciato così spesso al calcetto o a una visita da Abercrombie & Fitch. Ci daremo tempo, la cosa più preziosa. O forse non ne avremo, perché ci sono troppe cose da fare, le spese, il lavoro, il basket dei bambini, l’imu. Faremo l’amore, sì. Ma a un certo punto non sarà più bello come ora, da cerbiatti del Cantico delle Creature diventeremo balene spiaggiate in Cornovaglia. 

Ecco, ho cominciato da poco a parlarti e già sono terrorizzato: non solo perché la tua coinquilina ha acceso la luce del bagno e quell’ombra sembra proprio un’ascia, ma perché è ovvio che non ce la faremo mai. Chi siamo, noi due, per farcela? Per amarci ancora, e poi per sempre? È tutto troppo, troppo difficile. Tutto, ogni volta, finisce. E poi trovare lavoro è un miracolo e un mq a Quarto Oggiaro costa come Beverly Hills. È che tu sei bella quando dormi. È che io sono contento di essere qui. E non so se ce la faremo: ma, ecco, forse volevo solo dirti che io ho voglia di provarci comunque. Insieme.

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What do we seek from co-workers?


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Isn't that what we seek from a co-worker, boss, friend or even a fellow conference attendee?
  • Open to new ideas, leaning forward, exploring the edges, impatient with the status quo... In a hurry to make something worth making.
  • Generous when given the opportunity (or restless to find the opportunity when not). Focused on giving people dignity, respect and the chance to speak up. Aware that the single most effective way to move forward is to help others move forward as well.
  • Connected. Part of the community, not apart from it. Hooked into the realities and dreams of the tribe. Able and interested in not only cheering people on, but shining a light on how they can accomplish their goals.
Paradoxically, the fancier the conference, the more fabled the people around the table, the less likely you are to find these attributes. These attributes, it turns out, have nothing to do with fame or resources. In fact, fear is the damper on all three. Fear of failure, intimacy and vulnerability. Fear closes us up, causes us to self-focus and to disconnect.
When we find our own foundation and are supported in our work by those around us, we can get back to first principles, to realizing our own dreams and making our own art by supporting others first and always.

Thansk to Seth's Blog

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Life-changing speech


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How to.. listen!


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Live interaction still matters. Teachers, meetings, presentations, one on one brainstorms--they can lead to real change. The listener has nearly as big a responsibility as the speaker does, though. And yet, Google reports four times as many matches for "how to speak" as "how to listen." It's not a passive act, not if you want to do it right. If listening better leads to better speaking, then it becomes a competitive advantage. [...] The hardest step in better listening is the first one: do it on purpose. Make the effort to actually be good at it. Don't worry so much about taking notes. Notes can be summarized in a memo (or a book) later. Pay back the person who's speaking with enthusiasm. Enthusiasm shown by the expression on your face, in your posture, in your questions. Play back what you hear but in your own words, using your own situation. Don't ask questions as much as make statements, building on what you just heard but making it your own. Take what you heard and make it the foundation for what you are trying on as your next idea. If you disagree, wait a few beats, let the thought finish, and then explain why. Don't challenge the speaker, challenge the idea. The best way to honor someone who has said something smart and useful is to say something back that is smart and useful. The other way to honor them is to go do something with what you learned. Good listeners get what they deserve--better speakers.

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Make it fun!


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Sono (anche) le persone così a cambiare il mondo: quelle che insegnano con passione e si impegnano affinché gli studenti capiscano davvero la materia, senza memorizzare definizioni e regole ma cogliendo davvero il concetto che ne è alla base.

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Immigrazione ed economia (ma non solo)


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[...] As an economist, I am often surprised at the hostility that some segments of the population express toward immigration. Most members of my profession are far more receptive to it, and for three main reasons. 

First, many economists, especially conservative ones, have a libertarian streak. Ever since Adam Smith taught us about the wonders of free markets and the magic of the invisible hand, we have been loath to prohibit mutually advantageous trades between consenting adults. If an American farmer wants to hire a worker to pick fruits and vegetables, the fact that the worker happens to have been born in Mexico does not seem a compelling reason to stop the transaction.

 Second, many economists, especially liberal ones, have an egalitarian streak. They follow the philosopher John Rawls’s theory of justice in believing that policy should be particularly attuned to its impact on the least fortunate. When thinking about immigration, there is little doubt that the least fortunate, and the ones with the most at stake in the outcome, are the poor workers who yearn to come to the United States to make a better life for themselves and their families.

 Third, economists of all stripes recognize that our own profession has benefited greatly from an influx of talent from abroad. In just the last few weeks, the economics department at Harvard, where I am chairman, has brought in six candidates to be considered for two assistant professor positions. Of the six, three are Americans, one is German, one is Argentine, and one is a New Zealander. The jobs will be offered to those deemed to have most promise as teachers and scholars, regardless of nationality.

The competition from foreign-born economists makes it harder for American economists to get the best positions. But it would be hypocritical for American economists to argue against such competition, as we have long preached that nations are better off over all when they pursue a policy of free and open trade. This principle applies not only to manufactured goods like textiles and aircraft but also to labor services, including lectures on economics. The system of higher education in the United States is the world’s best in large part because it has long taken a global approach to hiring. The best students from abroad often come to the United States to earn their Ph.D.’s, and the best of these often stay here and join the faculties of American institutions. [...]

This competition from abroad may reduce the salaries of American-born economists like me, but it has improved the university, much to our students’ benefit. For one thing, such competition keeps down the university’s labor costs. Many parents are shocked at how high college tuition is, but it could be worse. The willingness of universities to tap foreign talent also means that our students can learn from the worlds’ best minds. America’s superb system of higher education has been an engine of growth for the entire economy, thanks in part to the immigration of scholars from abroad. I understand that not all workers in the United States will embrace foreign-born competitors with the same equanimity as a Harvard professor. That is especially true of those with fewer skills and opportunities.

Over the last several decades, for the most part, the wages of workers without any higher education have stagnated, while the wages of those with advanced degrees have risen. The main forces driving these trends are technological change, which tends to increase the demand for skilled workers relative to unskilled workers, and, to a lesser extent, international trade. But the immigration of unskilled workers from abroad may be a contributing factor, and one that is all too obvious when these immigrants vie for the same jobs as unskilled workers born in the United States. The best solution to wage stagnation is to promote educational attainment among Americans. That’s easier said than done, but the task is imperative nonetheless. We won’t substantially help unskilled workers who are already here by denying the American dream to others who wish to pursue it. 

 In the end, even as an economist committed to rational policy analysis, I have to acknowledge that the immigration debate also has a visceral, emotional element. In my case, that is shaped by family history. I am the grandson of four immigrants from Ukraine, who arrived in the United States about a century ago. None of them had more than a fourth-grade education, and none could speak English when they set foot on their new homeland. Yet they found work, made a living and raised families. They lived modest lives, but their children did better than they did, and their grandchildren did better still. Lucky for me, the American Indian did not pursue the enlightened immigration policy suggested by Mr. Paulsen.

Fonte: Gregory Mankiw, The New York Times
Immigrazione ed economia sono temi più vicini di quanto si pensi. Come dice Mankiw, confrontarsi con persone provenienti da altri Paesi stimola la competizione e migliora il risultato finale, esattamente come avviene nel libero mercato dei beni e dei servizi. Quello che il professore di economia non dice, però, è che ci sono tipi diversi di immigrazione e problemi diversi da risolvere. Non tutti gli immigranti portano conoscenze, titoli di studio e importanti qualifiche. Molti portano miseria, fame, sofferenza o criminalità (a volte come conseguenza della condizione sociale, a volte come opportunità di profitto). 

Indubbiamente ci sono anche (tanti) casi di perfetta interazione culturale, di "competizione" tra idee e di ottimi risultati ottenuti grazie a team internazionali, ma il bilancio tra i "problemi generati" dall'immigrazione e i vantaggi sociali non è sempre così scontato ed immediato, specialmente nei Paesi dove non ci sono barriere naturali che permettono una grande selezione in ingresso: ovviamente non si arriva negli Stati Uniti in gommone, e guarda caso il confine con il Messico è molto controllato, ed analogamente non si entra in Svizzera se non attraverso pochi valichi ben protetti, mentre non ci sono barriere per Italia, Francia, Germania.. Insomma, quando si decide di "accettare" solo chi ha un titolo di studio, una buona conoscenza della lingua e un discreto patrimonio economico (come succede certamente in USA e un po' anche in Svizzera) certamente tutto diventa più facile, e si può dire senza timore che accogliere persone provenienti da altri Paesi è una scelta vincente (è vero che i parenti di Mankiw erano poveri e senza titoli di studio, ma ora entrare in America è un po' più difficile..!).

L'immigrazione - o in generale le emigrazioni - rappresentano una questione molto delicata e complessa, che forse non si più risolvere con la logica economica del "libero mercato". Nessun emigrante è contento di lasciare la terra natia e partire a bordo di un gommone e patire la fame per giorni, rischiando di cadere in mare e affogare, e nessun emigrante è entusiasta della propria condizione sociale, questo è chiaro. Se a casa loro avessero tutti un bel lavoro, un buon sistema politico-sociale e qualche piccola "certezza" difficilmente se ne andrebbero, se non per un PhD (o simili) o per un'esperienza internazionale finalizzata principalmente ad arricchire la persona, ma non a sfamarla. Invece l'emigrazione vera è fatta anche (e soprattutto) di persone che vogliono solo trovare qualcosa da mangiare per sopravvivere, e che come tali non generano ricchezza ma piuttosto la "consumano" (almeno inizialmente), ed un approccio puramente "economico" al problema secondo me non può prescindere da queste valutazioni.

Ed ora un passo avanti. O tutti gli Stati si circondano di muri e filtrano chiunque entra, o forse nessuno dovrebbe farlo. Se tutti lo facessero, chi per caso nascesse in un Paese povero e disagiato resterebbe per sempre tale, senza possibilità di migliorare la propria condizione di vita. Se invece tutti ci rendessimo conto che non c'è differenza tra un americano, uno svizzero, un italiano o un marocchino, probabilmente ci troveremmo insieme per affrontare all'unisono un problema così importante. Di certo la soluzione non può essere "accogliere tutti" - perché non è sostenibile per l'economia di alcun Paese - ma neppure "accogliere solo i bravi", perché profondamente ingiusto nei confronti di chi non ha mai avuto possibilità. Invece puntiamo (tutti gli Stati, si intende) ad "accogliere secondo le nostre possibilità" e a dare opportunità a più persone possibili, ma con rigore e intransigenza nei confronti di sciupa le sue occasioni o non è disposto ad impegnarsi onestamente per migliorare la propria condizione di vita. E non perdiamo mai di vista il vero traguardo: far si che ognuno possa "viver bene a casa sua", cioè che in tutti i Paesi del mondo ci siano condizioni economiche e sociali adeguate alla vita delle persone che ci abitano. Utopia? No, un "giusto" futuro non può che essere in questa direzione. No?

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Economists do it better.


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Susan, we need to talk. I’ve been doing a lot of thinking lately. About us. I really like you, but ever since we met in that econ class in college I knew there was something missing from how I felt: quantitative reasoning. We can say we love each other all we want, but I just can’t trust it without the data. And after performing an in-depth cost-benefit analysis of our relationship, I just don’t think this is working out.

Please know that this decision was not rash. In fact, it was anything but—it was completely devoid of emotion. I just made a series of quantitative calculations, culled from available OECD data on comparable families and conservative estimates of future likelihoods. I then assigned weights to various “feelings” based on importance, as judged by the relevant scholarly literature. From this, it was easy to determine that given all of the options available, the winning decision on both cost-effectiveness and comparative-effectiveness grounds was to see other people. It’s not you, it’s me. Well, it’s not me either: it’s just common sense, given the nature of my utility function.

The calculations are fairly simple. At this point in my life, the opportunity cost of hanging out with you is fairly high. Sex with you grants me seventeen utils of pleasure, but I derive negative utils from all of the cuddling afterwards and the excessive number of buttons on your blouse that makes it very difficult to maneuver in the heat of the moment. I also lose utils when you do that weird thing with your hands that you think is affectionate but feels almost like you’re scratching me. Overall, I derive thirteen utils of pleasure on a typical Friday night with you, or fourteen if we watch The Daily Show as part of it (fifteen if they have a good guest on the show). Meanwhile, I could be doing plenty of other things instead of spending time with you. For example, I could be drinking at the Irishman with a bunch of friends from work. I derive between 20 and 28 utils from hitting on drunk slutty girls at the bar. Since Jeff always buys most of the drinks anyways, the upfront pecuniary costs are low, and I have no potential negatives in terms of emotional investment. However, most of those girls don’t laugh at my jokes, which drives down utils gained. Thus, I could get between 14 and 21 utils from a night out at the bar.

If you’re looking for the kind of guy who’s interested in maximizing the worst-off outcome regardless of potential gains—well, I’m not that guy. All you have to do is look at the probabilities and compare the feasible range of outcomes in terms of number of units of pleasure to see that we’re going to have to call this relationship quits. This may feel cold, but there’s nothing cold about well-reasoned analysis. Like all humans, I know I am fallible—and since I have a natural tendency to improperly discount the future, I have made sure to accurately determine present future value of costs and benefits. But even considering the diminishing marginal returns of hitting on the aforementioned drunk slutty girls, the numbers simply do not want us to be together. I know this breakup might come as a bit of a shock to you, which I have also factored in. The disappointed look on your face costs me 5 utils of pleasure, but the knowledge that this is the right decision in the long-term makes up for that. Additionally, I have included in my calculations the fact that as a courtesy I will have to pay for this dinner in its entirety, which, given the gender parity we have previously expressed in our relationship, would normally cost me only half that.

I want you to know that this decision isn’t just for me—it’s for you, too. I’ve done the calculations. There are plenty of eligible bachelors out there who are probably able to more vigorously, consistently, and knowledgeably have sexual intercourse with you. While the thought of you being with someone else causes me a substantial negative utility that makes me feel as though I am going to vomit, I know that in the aggregate everyone is better off, and therefore it is the right decision for us to make. There’s no need to try to persuade me otherwise, Susan. We just can’t let our feelings get in the way of the math. 

In the meantime, I need to get back home. My utility calculations tell me that the best thing I can do right now is strip down to my boxers, microwave a quesadilla, and watch a bunch of episodes of The Wire. It might seem strange and horribly unproductive, but it’s not me—it’s just my utility function.

Fonte:  McSweeney

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Termodinamica


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"Thermodynamics is a funny subject. The first time you go through it, you don't understand it at all. The second time you go through it, you think you understand it, except for one or two small points. The third time you go through it, you know you don't understand it, but by that time you are so used to it, it doesn't bother you any more."

Arnold Sommerfeld

Citazione obbligatoria, specialmente in tempo di esami.

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Cosa non si sente in campagna elettorale..


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Vorrei riportare alcune affermazioni di Silvio Berlusconi riportate sul Corriere, giusto per evitare che si perdano nei meandri del web:

  • «Al primo Consiglio dei Ministri aboliremo il finanziamento pubblico ai partiti»
    Molto interessante, soprattutto perché si tratta di un cavallo di battaglia del Movimento 5 Stelle, che è stato più volte denigrato proprio per questa proposta (sia da destra che da sinistra)
  • "E ribadisce l'idea per cui gli elettori «devono concentrare il voto ai grandi partiti». Quindi «se andiamo avanti a dare i voti al Giannino di turno non andremo da nessuna parte»
    Chiaramente un altro riferimento al M5S (e non solo), insomma un altro modo per dire "votate pure il PD, ma non altri partiti".. paura?
  • Infine un'ulteriore menzogna: "Poi ci tiene a sottolineare: «Il premier e il governo devono agire solo con i ddl che quando vanno in Parlamento ritornano dopo 600 giorni, avevamo delle priorità ora c'è l'abitudine di dire che non abbiamo fatto nulla»", ovviamente falso! Durante i governi Berlusconi i decreti legge (molto più rapidi dei ddl) sono stati usati più e più volte, anche per leggi decisamente non urgenti..
Scrivo perchè "verba volant" ma nel web "scripta non semper manent".. e allora meglio riportare le informazioni una volta di più che una volta di meno. Precisazione: non è un post "anti Berlusconi", ma semplicemente "anti menzogne" o "anti trucchetti". Ognuno ha le sue idee - ci mancherebbe - ma la coerenza è fondamentale.. soprattutto in politica.

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