Thinking and Deciding

Part II was concerned with thinking about beliefs. Part III is about decision making,
the thinking we do when we choose an action, including both the decisions that
affect only the decision maker and the decisions that affect others, that is, decisions
that raise moral questions. We shall also examine long-term planning, with special
emphasis on the choice of personal goals. Part III is concerned mostly with inference
rather than search — in particular, with how we infer a course of action from our
goals and from evidence concerning the consequences of our options for achieving
them.
Chapter 10 describes the fundamental normative model of decision making, the
idea that utility — or goodness of outcomes — should be maximized. This model
serves as a theoretical ideal that we can use to justify prescriptive models, and it
is also the basis of decision analysis, a set of formal yet practical methods used by
decision makers in business, government, and medicine. Chapters 11 and 12 review
some descriptive models of decision making. These models are considerably more
elaborate than any descriptive models we have encountered so far, and some of them
raise questions about how we should interpret the idea of utility maximization itself.
Should we, for example, take into account our feeling of regret that results from our
having made a decision that happened to result in a bad outcome (aside from our feelings
about the outcome itself)? Chapters 13 and 14 discuss the applications of utility
theory to medical and other decisions, and the problem of estimating utility from
judgments. Chapter 15 examines further our ability to make consistent quantitative
judgments without the aid of formal theories.
Chapters 16 through 18 extend the analysis to types of decision making that are
usually considered “moral,” that is, decisions that affect others. I argue that the fundamental
normative basis of decision making does not change when these considerations
are brought in: We still should try to maximize the utility of outcomes, but
we must consider outcomes for others as well as for ourselves. Chapter 19 discusses
planning and the potential conflict between goals for future outcomes and goals for
immediate outcomes. These conflicts are roughly analogous to those between self
and others: We can think of our future selves as somewhat different people from our
present selves. The book ends with a discussion of risk policy, which brings together
many of the issues discussed in this part.