/* ncinfm.sas                            */
 /*                                       */
 /* read infant mortality data            */
 /*                                       */
  options ls=80 ;
  data infm ;
   length county $12 ;        *****         tab delimited ;
   infile 'ncinfmort.txt' dlm='09'x dsd firstobs=6 ;
   if( _n_ > 100 ) then stop ;            * don't read footer ;
   input county totd totrate whd whrate mind minrate ; 
 run ;
 /*                                       */
 /* read county economic data             */
  data econ ;
    length county $12 ;                   * long county names ;
    infile 'NCCounty03q4.txt' dlm='09'x firstobs=2 ;
 /*                              ***** skip some vars  */
    input fips county cpop cpopr x1-x7 hinc pcpi90 pcpi01 pov ;
    county = upcase(county) ;             * same case as above ;
    drop x1-x7 ;
 run ;
 /*                                        */
 /* put them together                      */
 /*  but sort first                        */
  proc sort data=infm ;  by county ;  run ;
  proc sort data=econ ;  by county ;  run ;
  data both ;
    merge infm econ ;
      by county ;                          * always merge by ;
 run ;
 /*                                        */
 /* now the regression analysis            */
 /*  avoid the smallest counties but what  */
 /*   about Wake & Mecklenburg ?           */
  proc reg data=both ;
    where ( 2 < cpopr < 76 ) ;
    model totrate = pcpi01 ;    * per capita personal income ;
    title 'regression analysis of infant mortality on income' ;
 run ;
 /* may be useful later                    */
  proc means data=both mean var css ;
    var pcpi01 ;
 run ;
  proc plot data=both ;
    plot totrate*pcpi01 ;
 run ;


               regression analysis of infant mortality on income               1
                                                   17:54 Sunday, August 30, 2009
                               The REG Procedure
                                 Model: MODEL1
                          Dependent Variable: totrate 

                    Number of Observations Read          73
                    Number of Observations Used          73

                              Analysis of Variance
                                     Sum of           Mean
 Source                   DF        Squares         Square    F Value    Pr > F

 Model                     1       20.03609       20.03609       4.71    0.0333
 Error                    71      302.05652        4.25432                     
 Corrected Total          72      322.09260                                    

              Root MSE              2.06260    R-Square     0.0622
              Dependent Mean        8.86164    Adj R-Sq     0.0490
              Coeff Var            23.27559                       

                              Parameter Estimates
                           Parameter       Standard
      Variable     DF       Estimate          Error    t Value    Pr > |t|

      Intercept     1       12.45565        1.67360       7.44      <.0001
      pcpi01        1    -0.00015025     0.00006923      -2.17      0.0333

               regression analysis of infant mortality on income               2
                                                   17:54 Sunday, August 30, 2009

                              The MEANS Procedure
                           Analysis Variable : pcpi01 
 
                          Mean        Variance    Corrected SS
                  --------------------------------------------
                      23520.36     16440859.85      1627645125
                  --------------------------------------------
               regression analysis of infant mortality on income               3
                                                   17:54 Sunday, August 30, 2009
          Plot of totrate*pcpi01.  Legend: A = 1 obs, B = 2 obs, etc.
totrate |
     20 +
        |
        |
        |                        AA
     18 +
        |
        |
        |                          A
     16 +
        |
        |                 A
        |                        A A
     14 +
        |                         A
        |                              A              A
        |
     12 +                         A B  A A  A
        |                       A
        |                   A      A A A      A
        |                      A     AA  A AA  A
     10 +                           A       A     A
        |         A               A
        |                     AAA  A B A AA  A  A        A  A
        |                        AA       A  AA A    A
      8 +                       AA      B   A                            A
        |                        A B A  B  A       A
        |                         A   BA        AA      B B
        |                   A         AB    A A A                     A
      6 +                               C   A  A       A
        |                                            A
        |                             A
        |                         A
      4 +                      A
        |                          A     A
        |
        |                               A
      2 +
        |
        |                                A
        |
      0 +                      A
        |
        ---+----------+----------+----------+----------+----------+----------+--
         10000      15000      20000      25000      30000      35000      40000

                                         pcpi01