有做过结构模型的吗？
proc calis data=a1 cov;
lineqs return=betar rent+er,
       bsi=betab rent+eb;
   std  rent=vrent,
        er=ver,
        eb=veb;
run;
有什么错误？return,bsi是数据集a1的两变量，rent是隐变量。运行出现错误:
ERROR: Exogenous variable rent is neither manifest, F, E, nor D variable.
ERROR: Exogenous variable rent is neither manifest, F, E, nor D variable.
ERROR: Variable rent in STD statement is not independent.
sas帮助看了，没看懂