The equilibrium prices in asset markets, as stated by Keynes (1930): “…will be fixed at the point at which the sales of the bears and the purchases of the bulls are balanced.” We propose a descriptive theory of finance explicating Keynes’ claim that the prices of assets today equilibrate the optimism and pessimism of bulls and bears regarding the payoffs of assets tomorrow.
This equilibration of optimistic and pessimistic beliefs of investors is a consequence of investors maximizing Keynesian utilities subject to budget constraints defined by market prices and investor’s income. The set of Keynesian utilities is a new class of non-expected utility functions representing the preferences of investors for optimism or pessimism, defined as the composition of the investor’s preferences for risk and her preferences for ambiguity. Bulls and bears are defined respectively as optimistic and pessimistic investors. (Ir)rational exuberance is an intrinsic property of asset markets where bulls and bears are endowed with Keynesian utilities.
The equilibrium prices in asset markets, as stated by Keynes (1930): “…will be fixed at the point at which the sales of the bears and the purchases of the bulls are balanced.” We propose a descriptive theory of finance explicating Keynes’ claim that the prices of assets today equilibrate the optimism and pessimism of bulls and bears regarding the payoffs of assets tomorrow.
This equilibration of optimistic and pessimistic beliefs of investors is a consequence of investors maximizing affective utilities subject to budget constraints defined by market prices and investor’s income. The set of affective utilities is a new class of non-expected utility functions representing the attitudes of investors for optimism or pessimism, defined as the composition of the investor’s attitudes for risk and her attitudes for ambiguity. Bulls and bears are defined respectively as optimistic and pessimistic investors.
We propose Keynesian utilities as a new class of non-expected utility functions representing the preferences of investors for optimism, defined as the composition of the investor’s preferences for risk and her preferences for ambiguity. The optimism or pessimism of Keynesian utilities is determined by empirical proxies for risk and ambiguity. Bulls and bears are defined respectively as optimistic and pessimistic investors. The resulting family of Afriat inequalities are necessary and sufficient for rationalizing the asset demands of bulls and bears with Keynesian utilities.
Optimism-bias is inconsistent with the independence of decision weights and payoffs found in models of choice under risk, such as expected utility theory and prospect theory. Hence, to explain the evidence suggesting that agents are optimistically biased, we propose an alternative model of risky choice, affective decision-making, where decision weights — which we label affective or perceived risk — are endogenized.
Affective decision making (ADM) is a strategic model of choice under risk, where we posit two cognitive processes: the “rational” and the “emotional” processes. The two processes interact in a simultaneous-move intrapersonal potential game, and observed choice is the result of a pure strategy Nash equilibrium in this potential game.
We show that regular ADM potential games have an odd number of locally unique pure strategy Nash equilibria, and demonstrate this finding for affective decision making in insurance markets. We prove that ADM potential games are refutable, by axiomatizing the ADM potential maximizers.
Affective decision-making is a strategic model of choice under risk and uncertainty where we posit two cognitive processes — the “rational” and the “emotional” process. Observed choice is the result of equilibrium in this intrapersonal game.
As an example, we present applications of affective decision-making in insurance markets, where the risk perceptions of consumers are endogenous. We derive the axiomatic foundation of affective decision making, and show that affective decision making is a model of ambiguity-seeking behavior consistent with the Ellsberg paradox.
Affective decision-making is a strategic model of choice under risk and uncertainty where we posit two cognitive processes — the “rational” and the “emotional” process. Observed choice is the result of equilibirum in this intrapersonal game. As an example, we present applications of affective decision-making in insurance markets, where the risk perceptions of consumers are endogenous. We then derive the axiomatic foundation of affective decision making, and show that, although beliefs are endogenous, not every pattern of behavior is possible under affective decision making.
This paper proposes nonparametric statistical procedures for analyzing discrete choice models of affective decision making. We make two contributions to the literature on behavioral economics. Namely, we propose a procedure for eliciting the existence of a Nash equilibrium in an intrapersonal, potential game as well as randomized sign tests for dependent observations on game-theoretic models of affective decision making. This methodology is illustrated in the context of a hypothetical experiment — the Casino Game.