From that amuse bouche: > The result of this paper is that these two questions are linked
No such thing was proven or even shown to be plausible. On Wed, Sep 4, 2019 at 9:47 PM Donna Y <[email protected]> wrote: > > Donna Y > [email protected] > > > > On Sep 4, 2019, at 2:37 PM, Raul Miller <[email protected]> wrote: > > > > On Wed, Sep 4, 2019 at 2:19 PM Donna Y <[email protected]> wrote: > >> Evaluated weak-form EMF entails the effect of historic data—something > not available for a transaction that might be available in the future. > > > > But that information would be available in the future when the future > > becomes the present. > > According to Maymin, that might be in 20 tears—that means his suggested > method of proving P=NP couldn’t work for another 20 years. > > Why not propose a different Turing Machine and a Language it accepts—there > are infinitely many. The Church-Turing thesis states that any sufficiently > powerful computational model which captures the notion of algorithm is > computationally equivalent to the Turing machine. > > > > > > That said, for practical reasons (even ignoring regulations) it's not > > > possible to extract all meaning from historical data. This is > > > especially true in high monetary velocity contexts. There isn't enough > > > time to perform more than superficial calculations. > > Maymin invokes the term Bounded Rationality (coined by Herbert A. Simon. > In Models of Man) that says rational decisions are often not feasible in > practice because of the intractability of the decision problem and the > finite computational resources available for making them. > > No one is omniscient. EMH doesn't say that an efficient market price > system would make us so. > > "All meaning" isn't the sort of information Fama was claiming fair prices > transmit. > > Changes in stock prices convey relevant information about the supply and > demand and expected return on company shares in a way that allows people to > choose to buy, hold or sell those stocks as if they did consciously > calculate and understand factors that affected changes in value, even if > they don’t. > > A central planner needs to know about the changed value of firms in order > to distribute resources appropriately, whereas individual agents in a free > market are automatically encouraged to distribute their investments to > shares with improved value without having to consciously grasp why prices > change. > > > >> Market regulation aim to make the market competitive and fair as > >> well as efficient. What they may want to eliminate if a loophole > >> that would allow one or more participants to drain money from other > >> participants unfairly and also undermine the primary purpose of the > >> market which is to raise capital for firms. > > > > Market regulations attempt to do so. > > > > But regulations also have limits -- including jurisdictional limits. > > This leads to fraud related issues (which, are -- practically speaking > > -- another example of market inefficiency). > > Yes there is fraud or the possibility of fraud—does that make the market > inefficient by definition. Fine, see below, it says nothing about SAT-1 or > the class NP. > > > >> Even if market regulations eliminate market efficiency it is definitely > false that > >> market regulations eliminate NP-Completeness > > > > How [specifically] would this be false? > > In computational modeling the outputs of a computing system C are used to > describe some behaviour of another system S under some conditions. The > explanation for S’s behaviour has to do with S’s properties, not with a > computation performed by the model. > > If Maymin is correct that EMH is equivalent to a specific N-complete > problem C and if he solves the NP-complete problem then that proves C is in > P—it has an efficient solution. By Maymin’s proposed proof that would imply > EMH was efficient. > > If he could prove C has no efficient solution then by his logic the market > is not efficient. Proving C, an NP-Complete problem, has an efficient > solution proves P=NP. > > Else showing the market has regulators that make it inefficient then so be > it, EMH is not efficient by definition. That does not prove anything about > C or the class NP. > > > > > >> Economics is not mathematics—it is a social science attempting to > explain social phenomena and distribution of resources among people. > > > > Sure, but economics uses mathematics, and if the math being used is > > mathematically inconsistent, that means that any value in its results > > didn't come from the math. > > Yes I said that. CS and Economics use math. > > In computational explanation some behaviour of a system S is explained by > a particular kind of process internal to S—a computation—and by the > properties of that computation. The mathematical description A that > specifies the evolution of S only represents what is known about the > evolution of S. Some factors that influence S’s evolution might be > unknown, > > To include everything that is known about S in A may make the mathematics > analytically or computationally intractable. > > > > > Thanks, > > > > -- > > Raul > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA Quantitative Consultant ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
