SAS coding

Fit an OLS regression model to these data.

a. Analyze the residuals and comment on model adequacy.

b. Fit the lagged variables regression models shown in Eqs. (3.119) and (3.120) to these data. How do these models compare with the OLS model in part a?

Table B.20 US Internal Revenue Tax Refunds
Source: US Department of Energy - Internal Revenue Service, SOI Tax Stats - Individual Time Series Statistical Tables, http://www.irs.gov/taxstats/indtaxstats/article/0,,id=96679,00.html
Fiscal Year	Amount Refunded, millions dollars	National Population, thousands
1987	96,969	242,289
1988	94,480	244,499
1989	93,613	246,819
1990	99,656	249,464
1991	104,380	252,153
1992	113,108	255,030
1993	93,580	257,783
1994	96,980	260,327
1995	108,035	262,803
1996	132,710	265,229
1997	142,599	267,784
1998	153,828	270,248
1999	185,282	272,691
2000	195,751	282,193
2001	252,787	285,108
2002	257,644	287,985
2003	296,064	290,850
2004	270,893	293,657
2005	255,439	296,410
2006	263,501	299,103