Page 1 of 1

copy command with high2low conversion of panel data - a bug?

Posted: Mon Mar 02, 2020 4:23 am
by mamo
Dear Eviews team,

using Eviews 11 Sept 2019 Build, I encounter an unexpected behavior when using the "copy" command to copy panel data from a low-frequency to a high-frequency page. The requested frequency conversions are not carried through cross-section wise; rather, the data seems to be simply copied from the low-frequency page without conversion. In contrast, low2high frequency conversion seems to work properly.

See the test program provided below.

I consider the unexpected behavior in the high2low frequency conversion of panel data as a bug.

Best,

mamo

Code: Select all

!ncross=2
wfcreate(page=A) A 2000 2019 !ncross
series a=nrnd
pagecreate(page=Q) Q 2000 2019 !ncross
copy(o, c=repeata) A\a a_ra
copy(o, c=repeats) A\a a_rs
group g_low2high a_rs a_ra A\a
show g_low2high
' This works as expected only if !n=1, i.e., if the data in the annual page A is not a panel.
' If !na>1, the constant match sum, a_rs wrongly turns out to be equal to the constant match average average, a_ra (i.e., = A\a).
series q=nrnd
pageselect A
copy(o, c=a) Q\q q_a
copy(o, c=s) Q\q q_s
group g_high2low q_a q_s/4 Q\q
' High to low frequency conversion seems to work as expected, irrespective of whether !n=1 or !n>1.
'(i.e., the constant match sum, q_s is four times as large as Q\q, which is equal to the constant match average q_a)
show g_high2low

Re: copy command with high2low conversion of panel data - a bug?

Posted: Mon Mar 02, 2020 1:38 pm
by EViews Steve
Thanks for the example.

I've confirmed that the expansion constant match sum option (c=repeats) for panel to panel copy is not working as it should. Currently it appears that EViews will ignore any conversion option specified in the COPY command if the source and dest workfiles are panels. It will always perform a constant match average in this case.

For EViews 11, I've gone ahead and patched this to support constant match sum (at least for cross section by cross section). We may add support for the other expansion options at some point, depending on demand.

This change will be released in the next EViews 11 patch.

Re: copy command with high2low conversion of panel data - a bug?

Posted: Tue Mar 03, 2020 1:46 am
by mamo
Dear Eviews team

many thanks for the quick reply.

I would like to suggest that you make all the frequency conversion in the copy command available also when it is applied to panel data, as soon as it is feasible for you.

Best, mamo