Tuesday, September 9, 2008

Andrew Lo's hypothesis: conclusion

So if we've followed Lo's reasoning set out in yesterday's entry, we have a sense of how different species emerge. Speciation depends upon changes in economic conditions that change the adaptive behaviors into maladaptive ones, and force a re-jiggering. The specifics of the re-jiggering lead to distinct roles, or ecological niches, explaining the distinctions between hedge fund behavior and pensiuon fund behavior.

"The AMH is still under development.... Even at this early stage, though,
it seems clear that an evolutionary framework is able to reconcile many of the apparent contradictions between efficient markets and behavioral exceptions. The former may be viewed as the steady-state limit of a population with constant environmental conditions, and the latter involves specific adaptations of certain
groups that may or may not persist, depending on the particular evolutionary paths that the economy experiences."

Presumably, of a "steady state" stayed steady long enough, the different species might all mongrelize back into one another. In that respect, Lo's speciation is different from Darwin's. But that is a trivial point, because the steady state is only a theoretical "limit," -- change is the reliable reality. Species remain distinct.

One of the implications of the view is: "[I]nvestment strategies will also
wax and wane, performing well in certain environments and performing poorly in other environments. Contrary to the classical EMH in which arbitrage opportunities are competed away, eventually eliminating the profitability of the strategy designed to exploit the arbitrage, the AMH implies that such strategies may decline for a time, and then return to profitability when environmental conditions become more
conducive to such trades."

And that is where I will leave the matter for now.

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