Jan

22

 Thank you for passing along the Constructal Law of Design paper by Adrian Bejan.

Bejan's basic premise is that everything in nature is a flow. There are the obvious flows of things like water (rivers, blood) or air (lungs, air distributions systems), etc. In addition, he discusses flows of stress, for example, in the arrangement of the limbs on a tree, or the flow of animate mass, e.g., when a herd of animals runs or school of fish swims. His premise is that living systems are continuously changing and adapting their configuration to maximize the "currents that flow through" them. Even the building of the Egyptian pyramids, he argues, represents the flow of stones from a broad area to a single point (the pyramid). Here "living" systems (both animate and inanimate, such as rivers or pyramids being built) are constantly evolving and changing their configuration. When a system stops reconfiguring its flows, it dies: a dried-out river bead, dead animal, or completed pyramid receives no further maintenance, i.e., there is no more reconfiguration when something is dead.

Here is a Q & A on the concept of Constructal Design by a Forbes reporter and Bejan that has things described in less technical terms than his paper.

In terms of applying these concepts to trading, it seems to me that the obvious entity that flows is money.

One concern that I have, however, in adapting Bejan's ideas to a trading model is that, in the flows that he is describing, there is always a driving force from high to low: gravity pulls water down a landscape, a pressure differential drives air in and out of the lungs, a disturbance or threat forces animals to run in the opposite direction. As a result, all of the flows that he is describing are one-way, or unidirectional. This central to his entire theory, as the opposite behavior is prohibited from the Second Law of Thermodynamics: heat does not move from cold objects to hot on its own, rivers do not flow uphill, air does not come out of the lungs when the diaphragm expands to reduce the pressure in the lungs to draw air in, dropping the broken pieces of a coffee cup on the floor will never result in re-assembled cup, etc.

Thus it would seem that a critical element in adapting Bejan's ideas for trading will revolve around describing a driving force for the flow of money. This is really your expertise far more than mine, but let me start the dialog by suggesting that the driving force for money is the perceived potential for money growth (PPMG). 'Perceived Potential' here implies that there is an opportunity to make a profit from an investment, but that the outcome is not necessarily guaranteed (think of Enron and Bernie Madoff). Reconfiguration, also a key tenant to Bejan's ideas, happens with the flow of money from one instrument to the next. If we now draw the analog of a river basin, and that high PPMG is analogous to a low point in the flow of water over a landscape, then it can be seen that money will flow from regions of low potential (elevated areas, mountainsides) to regions of high potential (low areas, valleys). The lower the elevation, the more rapidly money will flow into it.

What complicates the analysis is that PPMG is a dynamic quantity. A company can be very profitable at one point in time (Kodak, General Motors, Blackberry), and thus have considerable growth potential, but over time, its growth potential can change. This is analogous to the river basin landscape changing constantly in elevation, and having the flow adjust accordingly. This does happen in nature as well, of course, both slowly (Colorado River/Grand Canyon) or quickly (earthquake/volcano). Such a time-varying landscape would be important to include in a trading model.

I think that the above would be a bare minimum to implement the ideas that Bejan is putting forth. I did do a quick search to see if people were using these ideas for trading (in particular) or finance/economics, but I did not find much. This is not a surprise: Bejan's ideas are new and different and thus will take some time to permeate to other areas. This, in itself, is an opportunity to seize the advantage. The risk, is, of course, that the ideas may not have significant utility in trading to upset the state-of-the-art now in place, and thus will not pay off after time spent trying to integrate them. This is the risk of adopting any new technology/idea, I suppose.

Anyway, there you have it: my rather disjointed ideas on the matter. I would be interested to see if Bejan's ideas could prove to be of utility for trading.

Jon Longtin, Ph.D., P.E. Professor Department of Mechanical Engineering 159 Light Engineering Bldg. State University of New York at Stony Brook Stony Brook, NY 11794-2300


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