“Those who have the upside are not necessarily those who incur the downside. For example, bankers and corporate managers get bonuses for “performance,” but not reverse bonuses for negative performance, and they have an incentive to bury risks in the tails of the distribution –& in other words, to delay blowups.
The ancients were fully aware of this incentive to hide risks,& and implemented very simple but potent heuristics. About 3,800 years ago, the Code of Hammurabi specified that if a house collapses and causes the death of its owner, the house’s builder shall be put to death.”
Foreign Policy has an article on their website with reflections from Nassim touching on Fragility/Antifragility, the stability of countries, city-states and decentralizing government, Lebanon, the European Union, and US deficits, titled Epiphanies from Nassim Nicholas Taleb.
Nassim Nicholas Taleb has made a career of going against the grain, and he has been successful enough that the title of his book The Black Swan is a catchphrase for global unpredictability far beyond its Wall Street origins. Born in Lebanon, he weathered the first few years of the civil war in the late 1970s reading philosophy and mathematics — from Plato to Poincaré — in his family’s basement. War taught him how quickly fortunes can change, an insight he soon applied to derivatives markets. For Taleb, investing is about “hyper conservatism,” which includes making lots of tiny bets on wildly unlikely events — like a currency crisis or the banking collapse, on which he made tens of millions of dollars. His newest project is helping governments get smarter about risks, and his fervent anti-euro message has helped win him the ear of British Prime Minister David Cameron.
Just posted on Nassim’s Facebook Wall:
Nassim Nicholas Taleb
Looks like a preview of what to expect from the economics and econophaster establishment. Davies is the gentleman there; others have not even given a simple thougth to model error and which domains are affected by it. But asking people to explain insults can lead to pleasant surprises.
When Taleb met Davies:
This morning, Nassim Taleb returned to Twitter, posting one of the technical appendices to his new book. And immediately he got into a wonderfully wonky twitterfight/conversation with Daniel Davies.
I don’t pretend to understand all the subtleties of the conversation between the two, but, for Tom Foster, here’s an attempt. Davies has promised a Crooked Timber post on other parts of the appendix; I’m really looking forward to that.
Read the rest here…
Nassim Taleb has posted a link to the technical Appendix II of his new upcoming book Antifragile on his website.
On his Facebook Page Nassim Taleb has linked to a new note on his Philosophical Notebook page on his website.
Link (note 150): http: // www. fooled by randomness. com/ notebook. htm
Nassim has released the “Medicine and Convexity (Antifragility), a summary (technical) sheet” on his Facebook Page.
A brief explanation of nonlinearities as detection of risk in medicine (from antifragile), directly from mathematical necessities, or the ideas behind Antifragile.
In the presence of a layer of metaprobabilities (from metadistribution of the parameters), the asymptotic tail exponent corresponds to the lowest possible tail exponent regardless of its probability. The problem explains “Black Swan” effects, i.e., why measurements tend to chronically underestimate tail contributions, rather than merely deliver imprecise but unbiased estimates.
Nassim Taleb has shared a new paper in PDF form on his Facebook Page titled: How We Tend To Overestimate Powerlaw Tail Exponents
In the presence of a layer of metaprobabilities (from metadistribution of the parameters), the asymptotic tail exponent corresponds to the lowest possible tail exponent regardless of its probability. The problem explains “Black Swan” problems, i.e., why measurements tend to chronically underestimate tail effects, rather than merely deliver imprecise but unbiased estimates.
The Bloomberg Businessweek website has a feature piece on Robert Rubin, in the article Nassim is interviewed and shares his view on President Clinton’s former Treasury Secretary and former Citigroup executive.
“Nobody on this planet represents more vividly the scam of the banking industry,” says Nassim Nicholas Taleb, author of The Black Swan. “He made $120 million from Citibank, which was technically insolvent. And now we, the taxpayers, are paying for it.”
Nassim Nicholas Taleb doesn’t know Rubin personally. He admits that his antipathy, like that of so many Rubin critics, is fueled by symbolism. “He represents everything that’s bad in America,” he says. “The evil in one person represented. When we write the history, he will be seen as the John Gotti of our era. He’s the Teflon Don of Wall Street.” Taleb wants systemic change to prevent what he terms the “Bob Rubin Problem”—the commingling of Wall Street interests and the public trust—“so people like him don’t exist.”
Nassim Taleb has released a paper with the IMF: A New Heuristic Measure of Fragility and Tail Risks: Application to Stress Testing
From Business Insider: NASSIM TALEB: The Fed Is Looking At The Banking System All Wrong
Nassim Taleb has long been a critic of traditional forecasting methods like the ones underlying these stress tests. He even coined a now oft-repeated term to capture his criticism – “black swan” – which became a huge New York Times bestselling book.
Now, he warns that “fragility is especially high for the banks with the worst outcomes” according to a new metric he’s developed to better analyze the risks facing the banks.
In a new white paper with researchers at the IMF, Taleb explains the reason why all of the stress tests conducted by central banks and international financial institutions like the Federal Reserve, the ECB, and the IMF come up short:
First, many stress tests focus on the point estimates of very few scenarios, and often pay little attention to how the impact would change in case of different scenarios, e.g., a slightly more severe one. Second, if stress tests do not take into account the possibility of model and parameter error, it can be misleading to rely only on the point estimates of even well-designed stress tests. Without considering the potential for these errors, one could miss the convexities/non-linearities that can lead to serious financial fragilities.
A better approach, according to Taleb and his IMF co-authors Elie Canetti, Tidiane Kinda, Elena Loukoianova, and Christian Schmeider, is to measure the difference between outcomes arising from different scenarios instead of focusing on the estimates of potential losses themselves.
According to Taleb, this is the real way to measure the “fragility” of a bank or a country in the event of a negative economic shock. Because point estimates are so prone to errors from faulty model assumptions, measuring the distance between them to detect how quickly losses pile up as the economic shock gets larger becomes a vastly more reliable measure of risk.
In other words, it’s not the size of the losses themselves that is important. Instead, it’s the rate of change of potential losses as the economic situation deteriorates that determines how fragile a bank is, by Taleb’s standards.