This variable is the amount of food stamps/SNAP benefits that a respondent received
in this month and year. The variable comes from the core file. I27AMT1-I27AMT4 in
1984; S27AMT in the 1990, 1991, 1992, and 1993 panels; T27AMT in the 1996, 2001, 2004,
and 2008 panels.