there are ways of doing this, but its a bit of a mess; I'd just match
without replacement if its possible.
Gary
On Sat, 26 Apr 2008, John Sheffield wrote:
Hi all,
When you match with replacement of the controls, should you incorporate any kind of
correction to your standard errors? If you have 100 treated units and 50 unique
controls, you'll only have 150 real observations; matching with replacement of
controls will give you 200 total units. That inflates your degrees of freedom with
units that don't really exist. How does this work? And does the correction depend
on
what percentage of units are in fact unique?
Thanks!
John