On 03/03/15 17:31, Sven Schreiber wrote:
FWIW Eviews used to not print p-values for the first lags I think, but
maybe that has changed.
If I'm not mistaken these Portmanteau type of tests do not only
require large T but also large m (max lag considered).
In most practical cases no, I think this is not true. m has to be large
enough to have a sense (including the relevant correlations) but not
very large because this may imply very low power.
So the whole business becomes even murkier when m is so small that
m-p-q becomes negative. Also using dof=m instead of m-p-q is not wrong
asymptotically I believe, it's all "just" about small-sample
corrections (which can be very important of course though).
If your T is very very
large you may calculate the Q stat for a very
large m, and then given p and q not very large, a chi-square(m) and
chi-square (m-p-q) may be similar. But usually we don't have so large T
and we are interested in relatively low values of m. From m>p+q we have
enough dof and the Q stat for a residuals series may have sense, and
the asymptotic distribution is chi-square (m-p-q) different from the
chi-square(m).
--
Firma Arista
*Ignacio Díaz-Emparanza*
Zuzendaria/Director
ignacio.diaz-emparanza(a)ehu.eus <mailto:ignacio.diaz-emparanza@ehu.eus>
94 6013732
*EKONOMIA APLIKATUA III SAILA (EKONOMETRIA ETA ESTATISTIKA)/
DEPARTAMENTO DE ECONOMÍA APLICADA III (ECONOMETRÍA Y ESTADÍSTICA)
UPV/EHU*
Avda. Lehendakari Aguirre, 83 | 48015 BILBAO
*T.: +34 946013740* | *F.: +34 946013754*
*www.ehu.eus/es/web/ea3* <
http://www.ehu.eus/es/web/ea3>
ERNE! Baliteke mezu honen zatiren bat edo mezu osoa legez babestuta
egotea. Mezuak badu bere hartzailea. Okerreko helbidera heldu bada
(helbidea gaizki idatzi, transmisioak huts egin) eman abisu igorleari,
korreo honi erantzunda. Kontuz! Mezua ez bada zuretzat, ez erabili, ez
zabaldu beste inori, ez kopiatu eta ez baliatu.
¡ATENCIÓN! Este mensaje contiene información privilegiada o confidencial
a la que sólo tiene derecho a acceder el destinatario. Si usted lo
recibe por error le agradeceríamos que no hiciera uso de la información
y que se pusiese en contacto con el remitente.
E-mail hau inprimatu baino lehen egiaztatu inprimatzeko beharra.
Antes de imprimir este e-mail piense bien si es necesario hacerlo.