1) Il problema - Come conoscere la nostra posizione nell'universo ragionando partendo dalla nostra condizione attuale? Non sappiamo molto, ma possiamo elaborare queste informazioni inmodo razionale.
2) Sappiamo per esempio che non riusciamo a metterci in contatto con altre civiltà aliene, eppure la loro presenza è molto probabile.
3) Guardando al nostro passato possiamo individuare alcuni stadi di avanzamento. Per esempio, siamo passati da un pianeta sterile a un pianeta che ospita la vita, poi la vita è diventata complessa fino alla comparsa dell'homo sapiens. Si tratta, vista la loro improbabilità, di "passi difficili" per raggiungere la nostra condizione.
4) Ma possiamo dire anche qualcosa di ragionevole sul futuro: qualora un'pocalisse non causerà la nostra estinzione, è presumibile che compariranno macchine intelligenti che costruiranno macchine intelligenti e poi macchine più intelligenti di noi che costruiranno macchine più intelligenti di loro. La nostra espansione, in mancanza di apocalisse, assumerà quindi un carattere esponenziale e ci consentirà di conquistare l'intero universo annientando le altre civiltà.
5) Sì, sebbene la cosa suoni strana ad orecchie abituate alla "musica pacifista" del momento attuale, dobbiamo pensare di essere governati da una legge evoluzionistica tale per cui il più forte mangia il più debole. Non sarà molto difficile inventare delle ragioni per giustificare moralmente la conquista.
6) Dicevo che tutto questo vale se saremo risparmiati dall'apocalisse. L'apocalisse puo' essere immaginata come un "passo difficile" particolarmente difficile. Di solito si parla di Grande Filtro. Dobbiamo capire se il Grande Filtro sta alle nostre spalle o davanti a noi.
7) In assenza di informazioni più specifiche dovremmo pensare che sta davanti a noi poiché il numero di civiltà immaginabili in uno scenario "prima del Grande Filtro" è molto più grande rispetto a quelle immaginabili "dopo il Grande Filtro" (altriment che filtro sarebbe)? Poiché è più sensato immaginarsi nella popolazione più numerosa, dobbiamo concludere che l'apocalisse sta davanti a noi, non dietro.
8) Ma, allo stesso tempo, possiamo anche dire che il nostro universo è molto giovane poiché il meccanismo evolutivo non ha avuto ancora il tempo di selezionare una civiltà dominante. Come lo sappiamo? Beh, dal fatto che siamo ancora vivi. Con l'apocalisse (Grande Filtro) davanti a noi ma tutto sommato ancora in buona salute.
APOCALISSE
Nel tentativo di sintetizzare le mie letture aventi per oggetto il futuro più distante, dovrei concludere che l'apocalisse è molto più vicina del previsto. Si tratta di argomenti aperti a mille ipotesi ma la più lineare mi sembra questa: il nostro universo sembra poter ospitare una moltitudine di civiltà intelligenti, purtroppo o per fortuna, al momento, nessuna si è fatta viva. Questo evento singolare avvalora la tesi per cui una civiltà, superato un certo livello di sofisticatezza tecnologica, sia destinata al collasso. Del resto, la cosa sembra abbastanza plausibile: comoda disponibilità di armi nucleari per tutti, vulnerabilità alle bombe biologiche, pericolo disallineamento di IA... è facile immaginarsi una FINE plausibile partendo dal punto in cui siamo. Più in generale potremmo concludere che esiste un collo di bottiglia che solo poche civiltà avanzate riescono a superare. Siamo forse tra quelle? Non abbiamo punti di riferimento ma lo scenario prevede che il "grande filtro" stia davanti a molti e dietro a pochi, cio' significa che è più probabile appartenere al primo gruppo che al secondo. Ergo, l'apocalisse è il nostro destino.
Alternative per coltivare speranze?
1) Puo' darsi che una civiltà avanzata ci abbia già colonizzato "in silenzio" e ci usi come simulazione per i suoi esperimenti, in questo senso ci proteggerebbe da un'eventuale autodistruzione. Mi sembra un'ipotesi alquanto bizzarra.
2) Le civiltà avanzate si sviluppano a ritmo impressionante e ben presto esauriscono gli atomi disponibili per accrescere il loro PIL. In questo senso non resta loro che dedicarsi all'interiorità lasciando perdere l'espansione fisica della loro influenza. Anche qui non sono convinto, questo potrebbe essere il destino finale di una civiltà che ha conquistato l'intero universo ma finché c'è espansione ci sono anche atomi disponibili da valorizzare.
Avvertenza: sento che il mio entusiasmo per Porro va in qualche modo moderato, il post che segue ha esattamente questa missione.
Porro (che seguo sempre con entusiasmo), in genere dice la verità. La urla. La urla scandalizzato dalle ipocrisie della politica. Come tutti coloro cresciuti "all'ombra dei lumi", puo' farlo perché si è dimenticato (o fa finta di dimenticarsi) che la verità non si dice. Toc toc... PORROOO! NON SI GOVERNA CON LA VERITA'! NON HAI STUDIATO I CLASSICI DELLA POLITICA? Questa amnesia l'ha reso ingenuo come i suoi arci-nemici, i grillini (quelli della prima ora che chiedevano streaming e webcam anche nel cesso del gabinetto del Consiglio dei Ministri). Mi spiego meglio esplicitando la tesi che sosterrò di seguito (ispirata molto indirettamente da Guido Vitiello).
Tesi: viviamo nell'epoca (modernità) e nel luogo fisico (Occidente) in cui il livello di politically correct è drammaticamente ai minimi storici.
Strano perché molti, io compreso, si lamentano del tipico linguaggio ipocrita dei giornali e della politica (grazie di esistere, Porro). Eppure, in passato l'ipocrisia non solo era praticata su ben più vasta scala ma anche risolutamente difesa e considerata indispensabile dalle più sottili menti in circolazione. La compattezza era tale da poterla dare per scontata. Questo sano ricorso al mascheramento delle "cose così come stanno" non si chiamava politically correct ma... "esoterismo", la sostanza cambiava poco: certe verità non possono essere comunicate impunemente alla massa poiché teoria e prassi divergono e molto spesso chi "sa" - a meno che non appartenga ad una selezionata élite - finisce per adottare condotte anti-sociali. Sulle questioni cruciali si scriveva/parlava in modo criptato affinché capissero pochi lettori/ascoltatori privilegiati. Siamo naturalmente inclini a liquidare l'intero esoterismo come incredibilmente arrogante ed elitario. Ma, solo pochi secoli fa, tutto il mondo era governato da monarchi e aristocratici e anche la maggior parte dei filosofi riteneva che la migliore forma di governo fosse una sorta di aristocrazia. In una società aristocratica ogni casta ha le proprie opinioni, i propri sentimenti, i propri diritti, i propri costumi e viveva un'esistenza separata, difficilmente credeva persino di appartenere alla stessa umanità delle altre caste. Per gli studiosi accreditati "... parlare del popolo... è proprio parlare di un animale pazzo, rimpinzato di milleuno errori e confusioni, privo di gusto, di piacere, di stabilità...". La verità deve essere lasciata segreta e non detta, poiché la moltitudine ha bisogno di uno stato d'animo appropriato piuttosto che di essere illuminata su verità che traviserebbe in ogni caso. Un altro studioso esprimeva così il pensiero mainstream: "... da un lato, come filosofo, preferisco la verità, mentre dall'altro, come cittadino, preferisco l'errore. L'errore è più alla portata di tutti; è il cibo generale delle menti di tutte le età e in tutti i luoghi...". Nessuna delle principali religioni includeva la menzogna in quanto tale - distinta dal "rendere falsa testimonianza" - nei cataloghi dei peccati gravi e sarebbe facile mostrare come la stragrande maggioranza dei pensatori del passato considerasse la "bugia bianca" come uno strumento chiave di governo. Socrate, nei dialoghi platonici, è descritto come rinomato in tutta Atene per non aver mai dato a nessuno una risposta diretta. Lo sprone era sempre quello: "ingannare i propri nemici a loro danno e i propri amici a loro vantaggio, e celare la verità in un modo da evitare sofferenze a coloro che altrimenti ne sarebbero inutilmente disturbati...". Mentire nel posto e nel modo appropriato era una delle prime virtù dello stoico. Lo stesso Gesù si rifugiava in oscure storielle: "... parlava al popolo in parabole, ma in privato ai suoi discepoli spiegava tutto". Fu lui a dichiarare: "... non date ciò che è santo ai cani; né gettate le vostre perle davanti ai porci...". Quando i discepoli lo interrogavano dicendo “perché parli [alla gente] in parabole?", lui rispose: "a voi è stato dato di conoscere i segreti del regno dei cieli, ma a loro non è stato dato...". E ancora: "... ho ancora molte cose da dirti, ma tu non puoi sopportarle ora". Per molti Gesù si esprime in parabole poiché la maggior parte di esse non sono chiarificatrici ma difficili da comprendere. Per Averroè "... la menzogna dei capi alla moltitudine è appropriata come un farmaco è appropriato per una malattia". I teologi del cristianesimo erano continuamente "d'accordo su alcune cose che non era comunque opportuno rendere note alle pecorelle del gregge...". C'è qualcosa di più sacro e inviolabile nella natura della bontà che in quella della verità, e quando è impossibile unirli insieme, la seconda deve lasciare il posto alla prima. Se escludiamo gli ultimi due secoli in occidente, il messaggio dell'esoterismo era accettato da tutte le civiltà in qualsiasi parte del pianeta, per quanto suoni strano alla trascurabile minoranza che rappresentiamo. Il "conoscere per deliberare" è una cazzata per il 98% dell'umanità vissuta sul pianeta azzurro.
Se guardiamo alle origini del pensiero moderno, una delle cose più sorprendenti è che il suo entusiasta abbraccio del progetto di armonizzare teoria e prassi era basato più su un salto nel buio che su qualsiasi prova concreta di un possibile successo. Che il "sapere" potesse condurre all' "agire retto" fu una congettura azzardata piuttosto che un argomento provato scrupolosamente. Gli inconvenienti si moltiplicarono e l'esoterismo dovette essere reintrodotto in fretta e furia in forme spurie generando fenomeni fastidiosi come, recentemente, il linguaggio prolisso della prima repubblica o l'odierno politically correct, una forma di ipocrisia con cui l'élite parla alla massa nel tentativo di spintonarla sulla retta via. Senonché, il popolo - indottrinato e insuperbito com'è da due secoli di pretenzioso illuminismo e autopercependosi élite per il solo fatto di aver frequentato l'università di massa - anziché sentirsi protetto, avverte l'umiliazione insita nel recupero di pratiche liquidate frettolosamente dalla storia e che ormai non possono che essere vissute come disoneste e truffaldine. In più, come se non bastasse, oggi ognuno di noi ha davanti un microfono nel quale è facile urlare questo sentimento profondo.
La letteratura di genere è vista come una letteratura scritta con una mano legata, occorre fare del proprio meglio osservando dei vincoli. In assoluto, il prodotto risulterà necessariamente inferiore alla letteratura pura, e questo sarà tanto più vero quanto più i vincoli saranno stringenti. Tuttavia, la performance dello scrittore potrebbe essere molto apprezzabile. Faccio un esempio, i vincoli del giallo sono decisamente stringenti e George Simenon difficilmente potrà mai rientrare nel canone occidentale, tuttavia sarà sempre uno scrittore degno della massima ammirazione, anche se paragonato ai massimi letterati. Infatti è proprio così ed è giusto che sia così.
Ecco, per la musica pop la sfida è simile: fare buona musica avendo come vincolo di rientrare nella Top Ten.
Few economists have had a greater influence on the financial markets than Eugene Fama. According to his Efficient Market Theory, competition among investors is so intense that all information and expectations are immediately and correctly priced in. Therefore, it’s impossible to beat the market in the long-term.
Never shy of making pointed statements, the Professor of Finance at the University of Chicago doubts the power of the central banks. «The business of central banks is like pornography: In essence, it’s just entertainment and it doesn’t have any real effects», he says. In contrast, he warns that investors could begin to question the credit worthiness of governments because of the high national debt levels.
In this in-depth interview with The Market/NZZ, which has been edited and condensed for clarity, Prof. Fama explains why he welcomes the boom in passive investing and why he sees no problem in the high capital concentration at tech giants like Apple, Amazon or Microsoft. In his view, absurd price swings such as negative oil prices are no reason to doubt the rational behavior of markets.
Professor Fama, the efficient market hypothesis has revolutionized the way people invest. What goes through your mind when you look at the wild swings the stock market made this year?
The market seems pretty good. It held up even though the economy is deep in the bucket. This is a good example of how forward looking the market really is: It’s looking past what we are going through now, and it’s saying that the future doesn’t look that bad.
Do you think that’s the correct assumption?
If I could forecast, I wouldn’t be a professor.
Still, since the crash in February/March, we basically went from 1929 to 1999 in just a few months. What are the chances stocks are in a bubble?
Bubbles are things people see in hindsight. They don’t identify them in advance. Sure, you can look at the behavior of prices, and you may be able to identify cases where they are too high. But if you only look back and say: «Oh, stocks went down a lot, so that was a bubble», then that’s 20/20 hindsight. At the time, there was no evidence that there was a bubble.
On the other hand, sometimes there are obvious signs of excess. Let’s take the final stage of the great dotcom bull market of the late nineties as an example.
Let’s go back to that period before the crash. Alan Greenspan, the head of the Federal Reserve, made his famous «irrational exuberance» speech about the market being too high in early December 1996. But even after the crash, the market never went back to the level when he made that speech. So what do you think of that forecast?
Is there really no way to spot a bubble?
Here’s another example: In the fifties, there was a famous professor at Stanford who was an agricultural economist. He brought plots of agricultural prices into the faculty lounge and asked people to identify bubbles. Of course, they saw the ups and downs, and all of them identified bubbles. Afterwards, he told them that these were just numbers he had randomly generated. That tells you how good people are with identifying bubbles.
Against that backdrop, what do you make of the growing discipleship of behavioral finance which focuses on the influence of psychology on investment decisions and questions the efficiency of markets?
What I say is that we agree on the facts but we disagree on the interpretation. In my view, there is no such thing as behavioral finance. Essentially, it’s just a criticism of efficient markets. They don’t have a theory of their own. Hence, that makes me the most important person in behavioral finance. Without me, they don’t have anybody to disagree with. So I think behavioral finance is just a branch of efficient markets.
But what about factors like emotions, herd mentality or cycles? Aren't they important at all?
Tastes and behavior are important in economics. Nobody denies that. But you have to translate these things into something testable, so we can take the data and test it, looking forward and not looking backward. That’s my response to all that stuff. It never works out.
Yet, we also know that investors regularly mix up similar-looking stock tickers or company names and thereby cause absurd movements in stock prices. How is this rational behavior?
It isn’t. You can identify mistakes like that. It’s common that names confuse investors and as a result, you can get temporary price movements. But they are usually tiny and go away quickly. I don’t say markets are completely efficient, but they’re efficient for most questions that I address. Models are never a 100% true. If they were, we would call them reality, not models. But for almost all purposes, market efficiency is a very good approximation. I’ll go even further: Almost all investors should regard markets as efficient for their own investment decisions. If they do that, they will be better off in the long-term.
Still, recently we saw some truly strange things that are hard to explain rationally, like negative oil prices or credit spreads on fortress balance sheet companies like Apple exploding. Is this the way rational markets are supposed to behave?
It’s always foolish to look at individual cases because every individual case is different. I don’t know how to judge those particular events and I don’t get into the business of valuing individual companies. But the fact that the oil price went briefly negative tells you that all storages were full. Therefore, people weren’t able to buy oil since there was no place to put it. The negative price didn’t last very long, but it shows you that once you start producing oil, this stuff keeps coming out of the ground no matter what. That means the price can go negative, and someone who has storage capacity can make money at that point.
Would you ever have expected to see negative oil prices?
We’ve seen a lot of things that we thought could never happen before. But they did, like negative interest rates all over the countries in Europe.
Negative interest rates are turning the financial system upside down. Are markets still able to function efficiently when bonds are yielding less than zero?
Negative interest rates tell you that there is some cost to storing cash. That’s why you get negative rates, mostly in short-term bonds. The alternative to holding those bonds is to hold cash, but holding cash is apparently not costless. This means you’re bound by the cost of holding cash. So, what do you do with your cash? If we’re talking about a position of hundreds of millions of dollars you don’t want to have that in cash.
And what about the fundamental consequences of negative rates? How are they impacting the real economy?
I don’t’ think they impact the real economy, but it’s a problem for the financial system. What’s more, in 2008, in response to the financial crisis, the Fed started to pay interest on its reserves. But there is no interest on the currency, and currency is exchangeable for reserves on demand by the banks. So based on classic monetary theory, you don’t really know what’s determining inflation at this point. There is no control over the stock of what qualifies as money, since reserves aren’t really money anymore because they are paying interest. That means you can't control the currency supply. In other words: Inflation is totally out of the control of central banks.
In the coming months, the Fed is expected to make a major commitment to ramping up inflation soon. What would it mean for investors if we really get inflation?
Inflation and return on investments is a tough topic that’s been around since the early seventies. In principle, you can see the effects of inflation on long-term interest rates, but you can’t see them in stocks very well because the volatility is so high. Hence, we don’t know what effect inflation will have on markets. It depends on the effect on real activity: High, but stable inflation wouldn’t be a big deal. What’s really a big deal is when it gets unstable.
It’s not just the Fed, around the globe central banks are flooding the system with liquidity like never before. Is this a reason for concern?
Frankly, I think this is just posturing. Actually, the central banks don’t do anything real. They are issuing one form of debt to buy another form of debt. If you are an old Modigliani–Miller person the way I am, you think that’s a neutral activity: You’re issuing short-term debt to buy long-term debt or vice-versa. That’s not something that should have any real effects.
Then again, the financial markets sure seem to love it. At least it looks like that the S&P 500 is moving upwards in tandem with the expansion of the Fed’s balance sheet.
Every day we hear a story about the movement of stock prices. But the story is different each day. So basically, these stories are made up after the fact. But when we look at it systematically, we don’t see a big effect of Fed actions on real activity or on stock prices or on anything else. That’s why I use to say that the business of central banks is like pornography: In essence, it’s just entertainment and it doesn’t have any real effects.
But how about the effects of this «free money» on borrowing? Isn’t the record amount of corporate and government debt a real problem?
That really bothers me. We haven’t hit it yet, but there has to come a point where people start questioning whether government debt is really riskless. Piling on debt even in good times is a new thing: In the US, we cut taxes and increased the deficit as a consequence, but that happened when the economy was booming. How are we going to pay that back? It has to come out of taxes in the future. As a matter of fact, we didn’t really lower taxes. What we did was we lowered them now and raised them in the future, when we have to pay off that debt. That’s why I worry that investors will become skeptical of whether governments can actually pay off so much debt. Now, we’re piling on like crazy because of the Covid-pandemic. That was unavoidable, but it was avoidable in the past, when we did it in good times. When does the market say «enough»?
In recent years, we’ve also witnessed a revolution in passive investing. How does the amazing indexing and ETF boom impact valuations of stocks and bonds?
That’s a complicated question, and nobody knows the answer. For almost sixty years, I have been saying that there should be more passive investing since there’s no evidence that active managers generate a superior performance for their high fees. Finally, passive investing is catching on. Of course, you can’t go 100% passive because somebody has to determine prices.
But aren’t ETFs undermining the generic price discovery of markets? In principle, they just buy stocks mechanically and don’t care about prices or valuations.
They don’t but the people who buy ETFs pay attention. But here’s the key issue: Who are you knocking out of the market when you go passive? Are you knocking out bad active investors or good active investors? If you are knocking out bad active investors, you are making the market more efficient. If you are knocking out good active investors, you are making it less efficient. In general, there are very few good active investors. That’s what all the evidence says, going back fifty years now: It’s very difficult to find people who can beat the market.
How about Warren Buffett for starters?
The real question is: How do you pick Warren Buffett? The way you pick him is after the fact, since he has done very well. Now, suppose I take 100,000 investors and say: Let’s let them run for 30 years and pick out the winner. Because you roll the dice so many times, even if none of them is a good or bad investor, many investors will do well and many will do poorly purely by chance. Statistically there is also going to be a big winner, but solely due to chance. In other words: There will be extremely good outcomes and extremely bad outcomes, but you just can’t tell who is successful because of luck and who because of skill.
So you’re saying that Warren Buffett was just lucky?
The problem with picking a winner after the fact is you can’t tell. If you would have identified him fifty years ago and you looked at him and would have said: «That’s the guy!», then I would believe you that you can tell if someone’s going to be an investment genius. But you couldn’t do that fifty years ago, because there’s a statistical problem.
Another concern people are talking about is the extremely high market concentration. Today, five tech giants make up more than 20% of the S&P 500. What does this mean for the efficiency of the stock market?
In the past, it’s always been the case that the largest fifty companies account for more than 50% of the total value of the market. Now, we’ve got a technological revolution, and it turns out that there are five or six big winners, these trillion-dollar companies. They are a pretty large fraction of the market, but they did it through innovation, not through theft or any other illegal behavior. So I don’t know why that’s a negative. These are all new businesses that provide new services we didn’t have before.
In addition to that, more trades than ever are based on algorithmic high-speed trading. How does that impact the functioning of financial markets?
This has been an open question for around fifteen years. No one really knows what effect high speed trading has on prices. One of my colleagues has worked a lot on that topic. His suggestion is to slow trading down to something like a tenth of a second between trades and thereby kill the advantage of these fast traders. I don’t see any problem with that.
There’s also a fierce debate about factor investing. For example, value has underperformed growth for the past decade. Is value investing death?
Who knows? The problem is that you can’t tell from ten years of data. We don’t know if the last ten years are just a statistical blip or not, because the variance of returns is so high. Ken French and I recently published a paper called «The Value Premium». We basically say that it’s not just ten years. If you go back 28 years and compare that period to the previous 28 years, you cannot tell whether expected returns have changed, or whether the premium is zero, or equal to its historical value. The volatility is so high that you can’t make any statements like that. There is no way to know the answer. Besides, the value premium has done poorly in the US, but not in international markets.
What does this mean for investors?
The challenge in asset pricing is to come up with the right dimensions of risk and how they relate to expected returns. That’s been a challenge as long as I have been in the business. I suggested solutions every twenty years or so. None of them worked perfectly. Sometimes they work for a while, and then they don’t seem to work anymore. The problem is that we’re always buried in volatility which makes it hard to tell what’s right and wrong.
What exactly are these risks?
We’ve identified what we call the five potential dimensions of risks: Stocks relative to bonds, small relative to big stocks, value relative to growth stocks, high versus low profitability stocks, and high investment versus low investment stocks. All of these things seem to capture some of the variation in returns. But whether that’s the right breakdown or not is hard to tell.
What sort of lesson should investors take from that? For example, can we say that small stocks should theoretically perform better than large stocks over the long run?
It’s really hard to tell because you get buried in volatility. For instance, the January effect, which refers to a premium of small stocks in the first month of the year, was identified in hindsight. And, once it was identified, it wasn’t there anymore. That begs the question whether the value premium, the size premium, the profitability premium or the investment premium were also temporary. If they are not real dimensions of risks and if they are not things people are concerned about, then you would expect them to go away because that’s fundamental economics: If there is a profit opportunity out there, and it’s generating expected returns, people will bid up or down the price on those things so that they disappear.
Is there anything you now would watch out for specifically as an investor right now?
This experience we’re going through is totally unusual. If you go back in the past, we experienced the same kind of pandemic in 1918 towards the end of World War I. But at that time, we didn’t take the same measures we’re taking now, shutting down whole economies. So we really don’t know what the response will be if and when there’s a cure for this disease. For instance, what will the response of consumers be at that point? Everybody wants to know if we are going to get a V-shaped response. But nobody knows because you don’t know what people are going to do when this is over.
What’s your advice for investors in this environment?
I don’t do investment advice. But the general prescription is to decide how much risk you’re willing to bear and then let that be guiding your decision into how much to put in stocks versus bonds. Also, stay away from hedge funds because you’re going to lose a lot of money fast.
Professor Fama is a prolific author, having written two books and published more than 100 articles in academic journals. He has done groundbreaking work with the Fama–French three-factor model. Developed with Dartmouth finance professor Kenneth French in the early 1990s, the model explains equity returns based on risk dimensions such as market risk, valuation and company size. Two additional dimensions were added later.
Dimensional Fund Advisors, an investment company founded by Professor Fama, Professor French and David Booth in 1981, is putting the insights from this model into practice. Today, the firm has more than $510 billion assets under management and employs over 1,400 people worldwide.
In his spare time, Eugene Fama is an avid golfer. Often, his golf partner is Professor Richard Thaler who also teaches economics at the University of Chicago and received the Nobel Prize in Economic Sciences in 2017 for his research in the field of behavioral finance - the new economic theory, which questions the thesis of rational markets.
