G

Dissenting Opinion

In multiple ways and places, Chapter 3 claims or implies that a utility-based decision making technique that we will call DA has, after numerous failures, largely been replaced by more modern methods. This appendix is a rebuttal. The subject is important because DA is one of the techniques that the Marines might better take advantage of.

In their seminal 1944 book, John von Neumann and Oskar Morgenstern (VNM) proved that rational decision makers will make decisions as if they were maximizing the expected value of some scalar quantity that VNM refer to as “utility.” Theirs is a mathematical theorem, so the word “rational” has the meaning implied by their assumptions. For example, VNM assume that a rational decision maker who prefers A to B, as well as B to C, will also prefer A to C. The idea of making decisions that maximize some scalar quantity (especially “profit”) considerably predates VNM; their contribution is to demonstrate that doing so is inevitable for rational decision makers. VNM do not assume that rational decision makers necessarily approach problems mathematically. You are probably acting rationally when you tie your shoes in the morning, even though mathematics is the furthest thing from your mind. A determined scientist could probably demonstrate that you are maximizing the time available for more productive pursuits (utility) by minimizing the time spent on shoe tying.

VNM make no claim about how actual humans make decisions, but we assert that human decisions are typically rational, and that a significant fraction of those decisions is currently guided by calculations that amount to maximizing utility. For lack of a better term, call this formal, utility-based approach to decision making Decision Analysis (DA). Chapter 3 uses several terms for the idea—SEU, normative analysis, etc.—but one will do here. DA has been greatly



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G Dissenting Opinion In multiple ways and places, Chapter 3 claims or implies that a utility-based decision making technique that we will call DA has, after numerous failures, largely been replaced by more modern methods. This appendix is a rebuttal. The subject is important because DA is one of the techniques that the Marines might better take advantage of. In their seminal 1944 book, John von Neumann and Oskar Morgenstern (VNM) proved that rational decision makers will make decisions as if they were maximizing the expected value of some scalar quantity that VNM refer to as “util- ity.” Theirs is a mathematical theorem, so the word “rational” has the meaning implied by their assumptions. For example, VNM assume that a rational decision maker who prefers A to B, as well as B to C, will also prefer A to C. The idea of making decisions that maximize some scalar quantity (especially “profit”) considerably predates VNM; their contribution is to demonstrate that doing so is inevitable for rational decision makers. VNM do not assume that rational decision makers necessarily approach problems mathematically. You are probably acting rationally when you tie your shoes in the morning, even though mathematics is the furthest thing from your mind. A determined scientist could probably demonstrate that you are maximizing the time available for more productive pursuits (utility) by minimizing the time spent on shoe tying. VNM make no claim about how actual humans make decisions, but we assert that human decisions are typically rational, and that a significant fraction of those decisions is currently guided by calculations that amount to maximiz - ing utility. For lack of a better term, call this formal, utility-based approach to decision making Decision Analysis (DA). Chapter 3 uses several terms for the idea—SEU, normative analysis, etc.—but one will do here. DA has been greatly 114

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115 APPENDIX G aided by the advent of modern computers, to the extent that making decisions that maximize utility is now widespread. The electric grid is managed this way, inventories are maintained this way, vehicle routes are determined this way, and people are routed around traffic jams this way. Missile defenses are planned this way, and crisis management teams (fire departments, police stations, emergency vehicles) are located this way. The idea pervades and improves modern life, even when it lies in the background. Microsoft Excel™ is distributed with an engine (Solver) the primary purpose of which is to maximize some scalar quantity. There are several journals that are at least partially devoted to DA, one of which is the eponymous Decision Analysis. There are large (thousands of attendees) meetings held regularly all over the world where much of the agenda is devoted to recount - ing the successes of DA and to enabling further application. Now, it is true that some human decision making is not rational in the sense of VNM. People sometimes have circularities in their preferences, especially when the alternatives are almost equally attractive. Humans also have a limited innate capacity for processing information, and even that capacity can be degraded by prolonged stress of the type that Marines sometimes endure. Not all attempts to apply DA succeed, and some should not even be attempted. All of these facts are undisputed, and ought to be considered by anyone tempted to apply DA to prob - lems of the type that Marine small unit leaders face. However, Chapter 3 makes far too much of these caveats and difficulties. Occasional failures should be expected in a technique as widely applied as DA, and lessons have been learned from them. Rationality ought to remain the default assumption, even in the midst of battle. There is no good reason for Marines to systematically adopt some other decision making paradigm where the irrationality of humans is a central tenet. The USMC regularly sends young officers to the Naval Postgraduate School and other universities for advanced education in Operations Research. A sig- nificant part of that education is devoted to rational decision making in varied circumstances, including circumstances that involve a sentient enemy. The fact that DA is alive and well is thus hardly news to the USMC. It is unfortunate that Chapter 3 states the contrary. Alan R. Washburn Steven Kornguth

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