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Traden4Alpha
Posts: 23951
Joined: September 20th, 2002, 8:30 pm

Antifragility

March 1st, 2013, 5:39 pm

Good points, crmorcom!The difference between "robust" and "antifragile" is that a robust system returns to normal after a shock and an antifragile system improves after a shock. Whether it's "worth a new word" depends on the costs of a new word vs. the benefits of a new word. To the extent that everyone understands fragility as negative response to shocks, it makes sense to posit the opposite as a positive response to shocks (which is not captured by "robustness"). To the extent that "robustness" implies a kind of stasis, it makes sense to want a new word that reflects more dynamic change.You are, of course, right than no system can handle arbitrarily large shocks. At the moment, we are all one asteroid strike away from oblivion. Yet the current system seems prone to collapse after a pebble falls -- Lehman Brothers had AUM equivalent to approximately 0.5% of global GDP (and negative equity of perhaps a few dozen bp of GDP). Policy makers worry about "to-big-to-fail" entities not realizing that the problem lies not in the entities but in the nonlinear coupling between the entities. Quite simply, worrying over TBTF solves nothing.I agree about your point about the issue of a forward looking economy with opportunistic agents. That seems like a valid criticism of antifragility. In a transition economy of mixed fragile and antifragile players, the antifragile players have a double-incentive to create volatility because volatility will strengthen their antifragile selves and shatter their fragile competitors. That does not seem so attractive. Yet I can't help but hypothesize that an antifragile system with subverting elements would be superior to the current state of a fragile system with subverting elements. In fact, given that we have subverting elements, shouldn't we attempt to create systems that decouple subversion and adapt to subversion to increase total performance in the presence of subversion?
 
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crmorcom
Posts: 452
Joined: April 9th, 2008, 4:09 pm

Antifragility

March 1st, 2013, 6:05 pm

I'm not sure robustness implies stasis. Merriam-Webster has:a: having or exhibiting strength or vigorous health b: having or showing vigor, strength, or firmness <a robust debate> <a robust faith> c: strongly formed or constructed : sturdy <a robust plastic> d: capable of performing without failure under a wide range of conditions <robust software> I suppose I'm worried that the static/brittle/rigid meaning of "robust" is being used as a straw man to try and promote a notion of "antifragility" that already exists within what a sane person would think of as a good economic/regulatory/risk-management framework/system. The value of the idea to Taleb is clear: it sells books and gets him on TV; for the rest of us, less so.Clearly, having a system that responds well - actually and in principle - to stresses is a good idea. I'm just not sure it's a new one. The difficulty is designing such a system well, not in realizing it's a sensible thing to want to do.
 
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Traden4Alpha
Posts: 23951
Joined: September 20th, 2002, 8:30 pm

Antifragility

March 1st, 2013, 6:57 pm

Those definitions of "robust" seem to have a bimodal character with respect to "vigor". Who would use "vigorous" in reference to software, a control system, or a plastic?"Capable of performing without failure under a wide range of conditions " is a much weaker condition than vigorous growth or Taleb's notion of antifragility. Unfortunately, engineering methods such as robust control and robust design are similarly much weaker than Taleb's notion of antifragility. Perhaps the problem is that the original definition of "robust" was intended more for living, growing, adaptable things (i.e., antifragile things) but was co-opted as a marketing term for plastics and software which might be non-fragile at best. As such the old word "robust" may be much the same as Taleb's definition. Unfortunately, the current word "robust" is too weak, especially in it's use in technical fields such as engineering, software, and controls, so that it misses the adaptive growth.
 
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mdubuque
Posts: 2411
Joined: July 22nd, 2004, 9:04 pm

Antifragility

March 9th, 2014, 2:09 am

QuoteOriginally posted by: daveangelQuoteHow would evolution have evolved (sounds like a bad English) if the world was not fragile ?Hi Dave, I hope I have understood your question.I think the issue is, what makes a species persist and thrive in a context of massive biological shocks over time?Taleb's point here is that multiple layers of redundancy, variably coded so as to hardwire flexible responses of that species to stochastic shocks that necessarily occur within a turbulent space, tend to insulate against extinction of that species over time. As such, the survival of that species may be said to be less "fragile", and is more likely to persist over time.
Last edited by mdubuque on March 8th, 2014, 11:00 pm, edited 1 time in total.
 
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Maelo
Posts: 1243
Joined: July 28th, 2002, 3:17 am

Antifragility

March 17th, 2014, 9:58 pm

sounds like coming from Mary Poppins
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