INPUT INSTRUCTIONS

  TITLE: 2-1-1 mediation random slope (MSEM)
  DATA: FILE IS 2-1-1.dat;
  VARIABLE:
  NAMES ARE ID x m y;
  USEVARIABLES ARE ID x m y;
  BETWEEN IS x;
  CLUSTER IS ID;
  ANALYSIS:
  TYPE IS TWOLEVEL RANDOM;
  MODEL:
  %WITHIN%
  m y; ! estimate Level-1 (residual) variances for m and y
  sb | y ON m; ! regress y on m
  %BETWEEN%
  x m y; ! estimate Level-2 (residual) variances for x, m, and y
  m ON x(a); ! regress m on x, call the slope "a"
  y ON m(bb); ! regress y on m, call the slope "bb"; bb = contextual effect, not the Between
  y ON x; ! regress y on x
  sb WITH x m y; ! estimate Level-2 covariances of sb with x, m, and y
  [sb](bw); ! estimate the mean of sb, call it "bw"
  MODEL CONSTRAINT: ! section for computing indirect effect
  NEW(b indb); ! name the Between b path and the indirect effect
  b=bb+bw; ! compute Between b path
  indb=a*b; ! compute the Between indirect effect
  OUTPUT:
  TECH1 TECH8 CINTERVAL;

*** WARNING in MODEL command
  In the MODEL command, the following variable is a y-variable on the BETWEEN
  level and an x-variable on the WITHIN level.  This variable will be treated
  as a y-variable on both levels:  M
*** ERROR
  One or more between-level variables have variation within a cluster for
  one or more clusters.  Check your data and format statement.

     Between    Cluster ID with variation in this variable
     Variable     (only one cluster ID will be listed)

      X          3054


已经非常仔细的检查了我的第二水平数据，在每一个cluster里面都相等啊

ID            y      m      x
3054        18        24        66
3054        16        32        66
3054        20        38        66