混合logit和条件logit模型-经管之家官网！

现在做conditional logit model遇到一个问题
. clogit Entry GS_Hst BC_Hst IP_Hst IC_Hst EC_Hst Cor_Hst MP_Hst RT_Hst LO_Hst ET_Hst DA_Hst, group(idyear)
note: multiple positive outcomes within groups encountered.
note: 12 groups (1,508 obs) dropped because of all positive or
all negative outcomes.
Iteration 0: log likelihood = -4969.6949
Iteration 1: log likelihood = -4969.1692
Iteration 2: log likelihood = -4969.1692
Conditional (fixed-effects) logistic regression
Number of obs = 45,237
LR chi2(11) = 365.27
Prob > chi2 = 0.0000
Log likelihood = -4969.1692 Pseudo R2 = 0.0355
------------------------------------------------------------------------------
Entry | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
GS_Hst | .1214454 .0241188 5.04 0.000 .0741735 .1687173
BC_Hst |-.0222558 .019965 -1.11 0.265 -.0613864 .0168749
IP_Hst | .0398417 .0212048 1.88 0.060 -.001719 .0814024
IC_Hst |-.0854415 .030382 -2.81 0.005 -.1449891 -.0258939
EC_Hst | .0555725 .0290507 1.91 0.056 -.0013658 .1125109
Cor_Hst | .0307806 .0439222 0.70 0.483 -.0553053 .1168665
MP_Hst | .0525695 .0313393 1.68 0.093 -.0088543 .1139934
RT_Hst |-.1731843 .027788 -6.23 0.000 -.2276477 -.1187209
LO_Hst |-.0710103 .0370406 -1.92 0.055 -.1436087 .001588
ET_Hst |-.1149088 .0283433 -4.05 0.000 -.1704606 -.059357
DA_Hst |-.1798415 .0238592 -7.54 0.000 -.2266047 -.1330782
------------------------------------------------------------------------------
但是如果我把case的个体变量加进来
. asclogit Entry GS_Hst BC_Hst IP_Hst IC_Hst EC_Hst Cor_Hst MP_Hst RT_Hst LO_Hst ET_Hst DA_Hst, case(idyear) alternatives(ISOHst) casevars(Age CrossList)
no cases remain after removing invalid observations
r(2000);
就显示没有case留下来了，其他的数据都是无效的数据。。。
我不知道啥原因