Sammenlign metoder

	Fourier Hausman-test	Instrumentelle variabler (IV) metode for kausal inferens
Fagfelt	Økonometri	Helseøkonomi
Familie	Regression model	Process / pipeline
Opprinnelsesår	2000s–2010s	1990s (modern applications)
Opphavsperson	Extends Hausman (1978) using Gallant's (1981) Fourier flexible functional form; applied in panel/time-series settings by Christopoulos & Leon-Ledesma (2004) and subsequent literature	Angrist & Pischke (applied econometrics); rooted in econometric theory
Type	Specification / endogeneity test	Method
Opprinnelig kilde	Christopoulos, D. K., & Leon-Ledesma, M. A. (2004). Current account sustainability in the US: What do we really know about it? Journal of International Money and Finance, 23(5), 821–840.	Angrist, J. D., & Pischke, J. S. (2009). Mostly Harmless Econometrics: An Empiricist's Companion. Princeton: Princeton University Press.
Alias	Fourier-Hausman endogeneity test, Fourier augmented Hausman test, nonlinear Hausman test, flexible Hausman specification test	IV, two-stage least squares, TSLS, causal estimation
Relaterte	5	3
Sammendrag	The Fourier Hausman test extends the classical Hausman endogeneity test by augmenting the regression with Fourier trigonometric terms — sines and cosines of time — so that the test remains valid even when the data-generating process contains smooth structural breaks or gradual nonlinearities that conventional linear specifications miss.	Instrumental variables (IV) is an econometric method to estimate causal effects when treatment or exposure is not randomly assigned and confounding is severe or unmeasured. IV relies on a third variable (instrument) that influences treatment but does not directly affect the outcome, allowing researchers to isolate the causal effect from the noise of confounding. Developed extensively in econometrics (Angrist & Pischke, 1990s–2000s), IV methods are increasingly used in health economics and health services research to leverage natural experiments and policy changes.