采用如下命令
xi:probit jg zlhs i.invention i.pclx jl dq wx es ygsssl yg_t bg_t ygsw zz ssajs i.ind i.year,rob
note: zlhs != 1 predicts success perfectly
zlhs dropped and 1406 obs not used
note: _Iinvention_1 != 0 predicts success perfectly
_Iinvention_1 dropped and 179 obs not used
这是什么原因?应该如何处理?