*running model on unbalanced data w/ up to 18 male & 19 female students;
*reading in unbalanced data;
DATA unbalanced;
	infile 'C:\Documents and Settings\djbauer\My Documents\CSEM\Multilevel\file2.dat';
	input school_id f3. ma1 f3. ma2 f3. ma3 f3. ma4 f3. ma5 f3. ma6 f3. 
          ma7 f3. ma8 f3. ma9 f3. ma10 f3. ma11 f3. ma12 f3.
          ma13 f3. ma14 f3. ma15 f3. ma16 f3. ma17 f3. ma18 f3.
          fe1 f3. fe2 f3. fe3 f3. fe4 f3. fe5 f3. fe6 f3. 
          fe7 f3. fe8 f3. fe9 f3. fe10 f3. fe11 f3.
          fe12 f3. fe13 f3. fe14 f3. fe15 f3. fe16 f3.
          fe17 f3. fe18 f3. fe19 f3. school_size f3.;
RUN;

* rearranging for PROC MIXED;
DATA unbalanced2; SET unbalanced;
	Array m[18] ma1-ma18;
	Array f[19] fe1-fe19;
	DO i = 1 to 37;
		IF i < 19 THEN DO;
			sex = 0;
			language = m[i];
		END;
		ELSE DO;
			j = i - 18;
			sex = 1;
			language = f[j];
		END;
		IF MISSING(language) THEN; ELSE output;
	END;
	drop i j ma1-ma18 fe1-fe19;
RUN;

proc mixed data=unbalanced2 covtest method=ml; 
  class school_id;
  model language = sex/solution ddfm=bw notest;
  random intercept sex/ type=un subject=school_id;
run;

                                         The SAS System    13:57 Thursday, February 20, 2003   3

                                      The Mixed Procedure

                                       Model Information

                     Data Set                     WORK.UNBALANCED2
                     Dependent Variable           language
                     Covariance Structure         Unstructured
                     Subject Effect               school_id
                     Estimation Method            ML
                     Residual Variance Method     Profile
                     Fixed Effects SE Method      Model-Based
                     Degrees of Freedom Method    Between-Within


                                    Class Level Information

                     Class        Levels    Values

                     school_id       131    1 2 3 4 5 6 7 8 9 10 11 12 13
                                            14 15 16 17 18 19 20 21 22 23
                                            24 25 26 27 28 29 30 31 32 33
                                            34 35 36 37 38 39 40 41 42 43
                                            44 45 46 47 48 49 50 51 52 53
                                            54 55 56 57 58 59 60 61 62 63
                                            64 65 66 67 68 69 70 71 72 73
                                            74 75 76 77 78 79 80 81 82 83
                                            84 85 86 87 88 89 90 91 92 93
                                            94 95 96 97 98 99 100 101 102
                                            103 104 105 106 107 108 109
                                            110 111 112 113 114 115 116
                                            117 118 119 120 121 122 123
                                            124 125 126 127 128 129 130
                                            131


                                          Dimensions

                              Covariance Parameters             4
                              Columns in X                      2
                              Columns in Z Per Subject          2
                              Subjects                        131
                              Max Obs Per Subject              35
                              Observations Used              2287
                              Observations Not Used             0
                              Total Observations             2287


                                       Iteration History

                  Iteration    Evaluations        -2 Log Like       Criterion

                          0              1     16491.06567939

                                         The SAS System    13:57 Thursday, February 20, 2003   4

                                      The Mixed Procedure

                                       Iteration History

                  Iteration    Evaluations        -2 Log Like       Criterion

                          1              2     16193.84965866      0.00011252
                          2              1     16193.10101848      0.00000407
                          3              1     16193.07598357      0.00000001


                                   Convergence criteria met.


                                 Covariance Parameter Estimates

                                                    Standard         Z
              Cov Parm     Subject      Estimate       Error     Value        Pr Z

              UN(1,1)      school_id     21.7938      3.8124      5.72      <.0001
              UN(2,1)      school_id     -3.5897      2.4297     -1.48      0.1396
              UN(2,2)      school_id      3.4174      2.2609      1.51      0.0653
              Residual                   62.1256      1.9503     31.85      <.0001


                                        Fit Statistics

                             -2 Log Likelihood             16193.1
                             AIC (smaller is better)       16205.1
                             AICC (smaller is better)      16205.1
                             BIC (smaller is better)       16222.3


                                Null Model Likelihood Ratio Test

                                  DF    Chi-Square      Pr > ChiSq

                                   3        297.99          <.0001


                                   Solution for Fixed Effects

                                         Standard
                Effect       Estimate       Error      DF    t Value    Pr > |t|

                Intercept     39.1161      0.4746     130      82.42      <.0001
                sex            2.6288      0.3800    2155       6.92      <.0001