Compara mètodes

	Almost Ideal Demand System	Model de preus hedònics
Camp	Economia	Economia
Família	Regression model	Regression model
Any d'origen	1980	1974
Autor original	Angus Deaton & John Muellbauer	Sherwin Rosen
Tipus	Flexible complete demand system in budget-share form	Revealed preference valuation method
Font seminal	Deaton, A., & Muellbauer, J. (1980). An almost ideal demand system. The American Economic Review, 70(3), 312–326.	Rosen, S. (1974). Hedonic Prices and Implicit Markets: Product Differentiation in Pure Competition. Journal of Political Economy, 82(1), 34–55.
Àlies	AIDS, Deaton-Muellbauer Demand System, LA-AIDS, Almost Ideal Demand Model	Hedonic Regression, Characteristics Pricing Model
Relacionats	3	3
Resum	The Almost Ideal Demand System (AIDS), introduced by Angus Deaton and John Muellbauer in 1980, is the workhorse flexible demand system in applied microeconomics. It models each good's budget share as a linear function of the logarithms of all prices and of log real total expenditure, derived from a flexible (PIGLOG) cost function. The form is 'almost ideal' because it satisfies the axioms of choice exactly, aggregates consistently over heterogeneous consumers, has a functional form that is a first-order approximation to any demand system, and can be estimated and tested for homogeneity and symmetry with linear regression once a price index is specified.	The hedonic pricing model, developed by Sherwin Rosen in 1974 and building on Kevin Lancaster's characteristics theory (1966), is an econometric method for valuing the implicit prices of product attributes by regressing market prices on observed characteristics. It reveals the trade-offs consumers are willing to make among product features and can be used to infer valuations of environmental amenities (e.g., air quality via house prices) and to adjust price indices for quality changes.