在应用计量经济学中,克服样本选择内生性问题的方法有Natural Experiment,Field Experiment, Instrumental Variable, Control Function, Matching, Difference in Difference, Regression Discontinuity 等。其中Difference in Difference是常用的做法。其基本思想是通过将实验组和对照组各自在政策前后的变量进行第一次差分(First ...
双重差分模型幻灯片+-+difference+in+differences+models
4、 absence of the intervention Key concept: can control for the fact that the intervention is more likely in some types of states7Three different presentations Tabular Graphical Regression equation8Difference in DifferenceBeforeChangeAfterChangeDifferenceGroup 1(Treat)Yt1Yt2Yt = Yt2-Yt1Group 2(Control...
–Crosssectionandtimefixedeffects •Usetimeseriesofuntreatedgrouptoestablishwhatwouldhaveoccurredintheabsenceoftheintervention •Keyconcept:cancontrolforthefactthattheinterventionismorelikelyinsometypesofstates 6 Threedifferentpresentations •Tabular•Graphical•Regressionequation 7 DifferenceinDifference ...
•Usetimeseriesofuntreatedgrouptoestablishwhatwouldhaveoccurredintheabsenceoftheintervention•Keyconcept:cancontrolforthefactthattheinterventionismorelikelyinsometypesofstates 6 Threedifferentpresentations •Tabular•Graphical•Regressionequation 7 DifferenceinDifference BeforeChange ...
•Usetimeseriesofuntreatedgrouptoestablishwhatwouldhaveoccurredintheabsenceoftheintervention •Keyconcept:cancontrolforthefactthattheinterventionismorelikelyinsometypesofstates Threedifferentpresentations •Tabular•Graphical•Regressionequation DifferenceinDifference BeforeChange Group1Yt1(Treat)Group2Yc1(Control...
–Crosssectionandtimefixedeffects •Usetimeseriesofuntreatedgrouptoestablishwhatwouldhaveoccurredintheabsenceoftheintervention •Keyconcept:cancontrolforthefactthattheinterventionismorelikelyinsometypesofstates 6 Threedifferentpresentations •Tabular•Graphical•Regressionequation 7 DifferenceinDifference ...
Regression equation Difference in Difference Key Assumption Control group identifies the time path of outcomes that would have happened in the absence of the treatment In this example, Y falls by Yc2-Yc1 even without the intervention Note that underlying ‘levels’ of outcomes are not important (...
他们认为身体是灵魂的容器,灵魂每天晚上会离开自己的身体,早上再回来 7 Threedifferentpresentations •Tabular •Graphical •Regressionequation 古埃及人相信他们死后会到死后世界去。他们认为身体是灵魂的容器,灵魂每天晚上会离开自己的身体,早上再回来 8 DifferenceinDifference Before Change After ChangeDifference ...
–Crosssectionandtimefixedeffects •Usetimeseriesofuntreatedgrouptoestablishwhatwouldhaveoccurredintheabsenceoftheintervention •Keyconcept:cancontrolforthefactthattheinterventionismorelikelyinsometypesofstates 6 Threedifferentpresentations •Tabular•Graphical•Regressionequation 7 DifferenceinDifference ...