Biens et servicesGoods are items that are usually (but not always) tangible, such as pens, physical books, salt, apples, and hats. Services are activities provided by other people, who include architects, suppliers, contractors, technologists, teachers, doctors, lawn care workers, dentists, barbers, waiters, online servers, a digital book, a digital video game or a digital movie. Taken together, it is the production, distribution, and consumption of goods and services which underpins all economic activity and trade.
Fonction de demande marshallienneEn théorie microéconomique, une fonction de demande marshallienne, d'après le nom de l'économiste anglais Alfred Marshall, décrit ce que le consommateur désire acheter en fonction des prix des biens sur le marché et de son revenu. Cette notion suppose que le consommateur est un homo œconomicus, c'est-à-dire capable de résoudre parfaitement le problème de maximisation d'utilité.
Local nonsatiationIn microeconomics, the property of local nonsatiation (LNS) of consumer preferences states that for any bundle of goods there is always another bundle of goods arbitrarily close that is strictly preferred to it. Formally, if X is the consumption set, then for any and every , there exists a such that and is strictly preferred to . Several things to note are: Local nonsatiation is implied by monotonicity of preferences. However, as the converse is not true, local nonsatiation is a weaker condition.
Coût d'opportunitéLe coût d'opportunité (de l'anglais opportunity cost), également appelé coût d'option, coût alternatif, coût de substitution, coût de renonciation ou encore coût de renoncement désigne la perte des biens auxquels on renonce lorsqu'on procède à un choix, autrement dit lorsqu'on affecte les ressources disponibles à un usage donné au détriment d'autres choix. C'est le coût d'une chose estimé en termes d'opportunités non réalisées, ou encore la valeur de la meilleure autre option non réalisée.
Théorie de la préférence révéléeLa Théorie de la préférence révélée est une théorie économique proposée par Paul Samuelson. Paul Samuelson a proposé de déduire les préférences des consommateurs en observant leurs choix. Plutôt que de les questionner sur leurs préférences en proposant plusieurs paniers de biens possibles afin d’obtenir des courbes d’indifférence, cette théorie se limite uniquement à l’observation du comportement des consommateurs. En faisant ses achats, le consommateur révèle ses préférences.
Aggregation problemIn economics, an aggregate is a summary measure. It replaces a vector that is composed of many real numbers by a single real number, or a scalar. Consequently, there occur various problems that are inherent in the formulations that use aggregated variables. The aggregation problem is the difficult problem of finding a valid way to treat an empirical or theoretical aggregate as if it reacted like a less-aggregated measure, say, about behavior of an individual agent as described in general microeconomic theory (see Representative agent, Heterogeneity in economics).
Expenditure functionIn microeconomics, the expenditure function gives the minimum amount of money an individual needs to spend to achieve some level of utility, given a utility function and the prices of the available goods. Formally, if there is a utility function that describes preferences over n commodities, the expenditure function says what amount of money is needed to achieve a utility if the n prices are given by the price vector . This function is defined by where is the set of all bundles that give utility at least as good as .
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.
