Incohérence temporellevignette|208x208px| F. Kydland et E. Prescott ont reçu le Prix d’Économie de la Banque de Suède en 2004. L'incohérence temporelle est une situation dans laquelle une politique économique décidée à un moment devient inutile quelque temps plus tard, souvent lorsqu'elle est entrée en œuvre. Il s'agit d'un concept utilisé en économie et en science politique. En 1977, les économistes Finn Kydland et Edward Prescott publient un article, Rules rather than discretion : The inconsistency of optimal plans, qui est très vite commenté par la profession économique.
Reduced formIn statistics, and particularly in econometrics, the reduced form of a system of equations is the result of solving the system for the endogenous variables. This gives the latter as functions of the exogenous variables, if any. In econometrics, the equations of a structural form model are estimated in their theoretically given form, while an alternative approach to estimation is to first solve the theoretical equations for the endogenous variables to obtain reduced form equations, and then to estimate the reduced form equations.
Innovation economicsInnovation economics is new, and growing field of economic theory and applied/experimental economics that emphasizes innovation and entrepreneurship. It comprises both the application of any type of innovations, especially technological, but not only, into economic use. In classical economics this is the application of customer new technology into economic use; but also it could refer to the field of innovation and experimental economics that refers the new economic science developments that may be considered innovative.
EndogénéitéEn économétrie, l'endogénéité se réfère généralement à une situation dans laquelle une des variables explicatives est corrélée avec le terme d'erreur. La distinction entre les variables endogènes et exogènes vient des modèles d'équations simultanées, où on sépare les variables entre celles qui sont déterminées par le modèle et celles qui sont prédéterminées. Ignorer la simultanéité dans l'estimation provoque un biais des estimateurs car cela viole l'hypothèse d'orthogonalité présente dans le théorème de Gauss-Markov.
Choix intertemporelUn choix intertemporel est un choix qui implique des évènements situés à des moments différents. L'étude des choix intertemporels consiste à déterminer dans quelle mesure les individus accordent une préférence au futur proche par rapport à un futur plus lointain, et à décrire les mécanismes psychologiques et cérébraux à l'œuvre. On peut montrer que pour qu'un individu effectue des choix stables au cours du temps, il faudrait que ses préférences soient une fonction exponentielle décroissante du temps, et cette analyse a été largement reprise en économie.
Simultaneous equations modelSimultaneous equations models are a type of statistical model in which the dependent variables are functions of other dependent variables, rather than just independent variables. This means some of the explanatory variables are jointly determined with the dependent variable, which in economics usually is the consequence of some underlying equilibrium mechanism. Take the typical supply and demand model: whilst typically one would determine the quantity supplied and demanded to be a function of the price set by the market, it is also possible for the reverse to be true, where producers observe the quantity that consumers demand and then set the price.
Time preferenceIn economics, time preference (or time discounting, delay discounting, temporal discounting, long-term orientation) is the current relative valuation placed on receiving a good or some cash at an earlier date compared with receiving it at a later date. Time preferences are captured mathematically in the discount function. The higher the time preference, the higher the discount placed on returns receivable or costs payable in the future. One of the factors that may determine an individual's time preference is how long that individual has lived.
Parameter identification problemIn economics and econometrics, the parameter identification problem arises when the value of one or more parameters in an economic model cannot be determined from observable variables. It is closely related to non-identifiability in statistics and econometrics, which occurs when a statistical model has more than one set of parameters that generate the same distribution of observations, meaning that multiple parameterizations are observationally equivalent.
Hyperbolic discountingIn economics, hyperbolic discounting is a time-inconsistent model of delay discounting. It is one of the cornerstones of behavioral economics and its brain-basis is actively being studied by neuroeconomics researchers. According to the discounted utility approach, intertemporal choices are no different from other choices, except that some consequences are delayed and hence must be anticipated and discounted (i.e., reweighted to take into account the delay). Given two similar rewards, humans show a preference for one that arrives sooner rather than later.
