Regarding my previous reply. The moment I sent it I realized my wording was rather rude. My apologies. What I meant to say was that I appreciate Ignacio bringing those papers to my attention and that I support a brief discussion be included in docs. I did not mean to imply that it was my decision in any way. I am very happy to leave leading in the very capable hands of people like Allin and Jack.  I hope I didn't offend anyone.

Cheers

Logan

Logan J. Kelly, Ph.D.
Associate Professor, Department of Economics, University of Wisconsin-River Falls
Director, UWRF Center for Economic Research,http://www.uwrf.edu/cer

Schedule a meeting: https://freebusy.io/logan.j.kelly@gmail.com

Office: (715) 425-4993
Mobile: (401) 256-0986
University Email: logan.kelly@uwrf.edu

From: Ignacio Diaz-Emparanza
Sent: Friday, October 14, 8:17 AM
Subject: [Gretl-devel] Hodrick-Prescott parameter
To: Gretl development

I see that gretl uses by default the value lambda=1600 for quarterly data, lambda = 100 for annual data and lambda=14400 for monthly data. For the quarterly case this was studied in the HP article and this value has been adopted almost as a "convention" for obtaining a trend/cycle decomposition. The values for annual and monthly data has been during some time subject to controversy. In particular, some papers consider the above values inappropiate because the agregation(from monthly to quarterly or quarterly to annual) of the trend gives very different results. But now, based on this requirement of equivalence on agregation, it seems that finally an agreement has been reached. It implies lambda(annual)=6.25 and lambda(monthly)=129600 or more generally lambda(S)=6.25*S^4 being S the seasonal periodicity. I suggest that gretl adopts these defaults. In these papers we have different justifications for such a formula: Maravall, A. y del Rı̀o, A. (2001), Time aggregation and the Hodrick- Prescott filter, Working paper 0108, Banco de España. Ravn, M. O. y Uhlig, H. (2002), ‘On adjusting the Hodrick-Prescott filter for the frequency of observations’, The Review of Economics and Statistics 84(2), 371–380. de Jong, R. M. y Sakarya, N. (2016), ‘The econometrics of the Hodrick- Prescott filter’, The Review of Economics and Statistics 98(2), 310–317. -- Ignacio Díaz-Emparanza Departamento de Economía Aplicada III (Econometría y Estadística) Universidad del País Vasco - Euskalherriko Unibertsitatea, UPV/EHU Tfno: (+34) 94 601 3732 http://www.ehu.eus/ea3 _______________________________________________ Gretl-devel mailing list Gretl-devel@lists.wfu.edu http://lists.wfu.edu/mailman/listinfo/gretl-devel