Date:         Sun, 5 Dec 1999 15:31:15 EST
Reply-To:     PGall9898@AOL.COM
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Philip Gallagher <PGall9898@AOL.COM>
Subject:      When large number of significant digits may be required - Gov't
              economics
Content-Type: text/plain; charset="us-ascii"

For persons who are wondering when very large numbers
of significant digits may actually make sense:

When I worked for the UN I was told by some folks from
the economics side that most computer packages were
inappropriate for their use, because they had to produce
documents summed for entire countries - yet all the totals
had to exactly match the sums of the individual entries.
When you remember the incredible inflations that occasionally
occur, you can readiy imagine that 16 or 17 significant
digits might not suffice.  It's akin to the problem of not
having the percentages in a PROC FREQ add up to exactly
100%.

I make no claims for whether or not the reporting requirements
for some kinds of international economics documents make
much sense;  that's their business.

We're accustomed to getting into significant digit trouble
when inverting matrices - these unlucky folks have trouble
when only adding and subtracting!

Phil Gallagher