Although the finding that shelter intake declined in association with the inception
of the voucher program, the presence
of extraneous (confounding) factors associated both with time and shelter intake can not be ruled
out, including
migration into and
out of the
county (although the human population actually increased during the study period).
«From 2009 to 2011, Maricopa
County saw much lower net migration [net domestic and international migration] than in the years before or after, which caused the county to drop out of the top population - gaining cou
County saw much lower net
migration [net domestic and international
migration] than in the years before or after, which caused the
county to drop out of the top population - gaining cou
county to drop
out of the top population - gaining
counties.