Heckman两阶段.pptx

nHeckmanSelectionModeln赫克曼备择模型n赫克曼二阶段备择模型n王志刚有几篇关于Heckman备择模型的文章。nselect(.)specifies the variables and options for the selection equation.It is an integral part of specifying a Heckman model and is required.nThe selection equation should contain at least one variable that is not in the outcome equation.nIf depvar_s is specified,it should be coded as 0 or 1,with 0 indicating an observation not selected and 1 indicating a selected observation.If depvar_s is not specified,observations for which depvar is not missing are assumed selected,and those for which depvar is missing are assumed not selected.nTheStatapackagehastwocomponents:theexecutableandtheado-files.n.updateexecutable,forcen.updateado,forcenHeckmanlweducationagechildren,select(agemarriedchildreneducation)nolognSTATA对大小写敏感。nHeckmanlweducationagechildren,select(w=agemarriedchildreneducation)nologBDCEND