Compara mètodes

	Test d'arrels unitàries de panell de Fisher	Test de raig unitari de panell Im-Pesaran-Shin (IPS)
Camp	Econometria	Econometria
Família	Hypothesis test	Hypothesis test
Any d'origen	1999	2003
Autor original	G. S. Maddala & Shaowen Wu	Im, Pesaran & Shin
Tipus	Nonparametric combination-of-p-values panel unit-root test	Panel unit-root test allowing cross-sectional heterogeneity
Font seminal	Maddala, G. S., & Wu, S. (1999). A comparative study of unit root tests with panel data and a new simple test. Oxford Bulletin of Economics and Statistics, 61(S1), 631–652.	Im, K. S., Pesaran, M. H., & Shin, Y. (2003). Testing for unit roots in heterogeneous panels. Journal of Econometrics, 115(1), 53–74.
Àlies	Maddala-Wu Test, Fisher-type Panel Unit-Root Test, MW Panel Unit-Root Test, Fisher Panel Birim Kök Testi	IPS Test, IPS Panel Unit-Root Test, Heterogeneous Panel Unit-Root Test, Im-Pesaran-Shin Birim Kök Testi
Relacionats	3	3
Resum	The Fisher-type (Maddala-Wu) panel unit-root test, introduced in 1999, combines individual-level ADF unit-root p-values using Fisher's chi-squared meta-analytic framework to produce a single panel-level test statistic. Unlike the Levin-Lin-Chu approach, it does not impose a common autoregressive parameter across cross-sections, making it a natural choice for heterogeneous panels in macroeconomics, finance, and regional economics.	The Im-Pesaran-Shin (IPS) test, introduced by Im, Pesaran, and Shin in 2003, is a panel unit-root test designed for heterogeneous panels where the autoregressive coefficient is allowed to differ across cross-sectional units. It averages individual Augmented Dickey-Fuller (ADF) t-statistics and constructs a standardized statistic with a standard normal limiting distribution, making it one of the most widely applied first-generation panel unit-root tests in applied econometrics.