adaptive expectations การใช้

• Adaptive expectations were instrumental in the Phillips curve outlined by Milton Friedman.
• However, in this framework it is clear why and how adaptive expectations are problematic.
• Rational expectations theories were developed in response to perceived flaws in theories based on adaptive expectations.
• Lucas elaborated a new approach in which rational expectations were presumed instead of the Friedmanian adaptive expectations.
• Under adaptive expectations, expectations of the future value of an economic variable are based on past values.
• For Friedman, workers form adaptive expectations, so the government can easily surprise them through unexpected monetary policy changes.
• Agent-based models of financial markets often assume investors act on the basis of adaptive learning or adaptive expectations.
• This has largely replaced adaptive expectations in macroeconomic theory since its assumption of optimality of expectations is consistent with economic theory.
• For example, Friedman postulated adaptive expectations, while Lucas assumed his economic agents to be able to form rational expectations.
• This is the reason why the theory of adaptive expectations is often regarded as a deviation from the rational tradition of economics.
• Nicholas Kaldor proposed a model of fluctuations in agricultural markets called the cobweb model, based on production lags and adaptive expectations.
• Prior to this paper, the dominant explanation for costly price stabilization programs relied on mechanical factors like adaptive expectations / Phillips curve.
• In " adaptive learning " or " adaptive expectations " models, investors are assumed to be imperfectly rational, basing their reasoning only on recent experience.
• Under adaptive expectations, if the economy suffers from constantly rising inflation rates ( perhaps due to government policies ), people would be assumed to always underestimate inflation.
• This seems to indicate that adaptive expectations is a misleading assumption how could farmers fail to notice that last period's price is " not " a good predictor of this period's price?
• In his paper " Optimal Properties of Exponentially Weighted Forecasts ", which was published in the " Journal of the American Statistical Association " in 1960, Muth rationalized Friedman s adaptive expectations model for permanent income.
• Broadly speaking, models with heterogeneous agents fall into the category of agent-based computational economics ( ACE ) if the agents have adaptive expectations, or into the category of dynamic stochastic general equilibrium ( DSGE ) if the agents have rational expectations.
• Milton Friedman, assuming adaptive expectations, distinguished a series of short-run Phillips curves and a long-run one, where the short-run curves were supposed to be the conventional, negatively sloped curves, while the long-run curve was actually a vertical line indicating the natural rate of unemployment.
• One simple version of adaptive expectations is stated in the following equation, where p ^ e is the next year's rate of inflation that is currently expected; p ^ e _ {-1 } is this year's rate of inflation that was expected last year; and p is this year's actual rate of inflation: