来自图书《MPlus中介调节模型》
模型公式:
1. Y = b0 + b1M + c1'X1 + c2'X2;
2. M = a0 + a1X1 + a2X2;
代入与化简:
将 M = a0 + a1X1 + a2X2 代入 Y = b0 + b1M + c1'X1 + c2'X2, 得到:
Y = b0 + b1(a0 + a1X1 + a2X2) + c1'X1 + c2'X2
展开括号,得到:
Y = b0 + a0b1 + a1b1X1 + a2b1X2 + c1'X1 + c2'X2
重组公式:
Y = (b0 + a0b1) + (a1b1 + c1')X1 + (a2b1 + c2')X2
效应计算:
* X1 对 Y 的间接效应: a1b1
* X2 对 Y 的间接效应: a2b1
* X1 对 Y 的直接效应: c1'
* X2 对 Y 的直接效应: c2'
USEVARIABLES = X1 X2 M Y;
ANALYSIS:
TYPE = GENERAL;
ESTIMATOR = ML;
BOOTSTRAP = 10000;
! In model statement name each path using parentheses
MODEL:
Y ON M (b1);
Y ON X1 (cdash1);
Y ON X2 (cdash2);
M ON X1 (a1);
M ON X2 (a2);
! Use model constraint to calculate indirect and total effects
MODEL CONSTRAINT:
NEW(a1b1 a2b1 TOTALX1 TOTALX2);
a1b1 = a1*b1;
a2b1 = a2*b1;
TOTALX1 = a1*b1 + cdash1;
TOTALX2 = a2*b1 + cdash2;
USEVARIABLES = X1 X2 M Y;
ANALYSIS:
TYPE = GENERAL;
ESTIMATOR = ML;
BOOTSTRAP = 10000;
! In model statement name each path using parentheses
MODEL:
Y ON M (b1);
Y ON X1 (cdash1);
Y ON X2 (cdash2);
M ON X1 (a1);
M ON X2 (a2);
! Use model constraint to calculate indirect and total effects
MODEL CONSTRAINT:
NEW(a1b1 a2b1 TOTALX1 TOTALX2);
a1b1 = a1*b1;
a2b1 = a2*b1;
TOTALX1 = a1*b1 + cdash1;
TOTALX2 = a2*b1 + cdash2;
OUTPUT:
STAND CINT(bcbootstrap);