Hello, I want to employ DiD with Propensity Score Matching to conduct the impact analysis for a policy implemented in 1998.
My original firm-level data before matching is given as below:
For matching, I tried the following:
In this way, I lose all the post treatment periods, which is the main problem.
Could you help me with how to merge a complete set of dataset for DiD with matched data with both pre- and post-treatment periods?
My original firm-level data before matching is given as below:
For matching, I tried the following:
Code:
drop if year >= 1997 probit treated1 ln_asset ln_ebit ln_l ln_k predict pscore psmatch2 treated1 ln_asset ln_ebit ln_l ln_k, outcome(lshare1) noreplacement com cal(0.1) gen pair = _id if _treated==0 replace pair = _n1 if _treated==1 label var pair "psmatch2 id of pairs" bysort pair: egen paircount = count(pair) drop if paircount !=2 drop paircount _nn _id _n1 sort uniqueid year save "matched.dta", replace merge 1:1 uniqueid year using "original.dta" keep if _merge == 3
Could you help me with how to merge a complete set of dataset for DiD with matched data with both pre- and post-treatment periods?
Code:
* Example generated by -dataex-. For more info, type help dataex clear input float(uniqueid year treated1 postreform) byte ksic2c float(hhi_sales lshare1 ln_y ln_k ln_l) 1 1991 0 0 21 .05181734 .4897 23.96307 23.431915 6.861712 1 1992 0 0 21 .05352982 .4364 24.189575 23.73835 6.887553 1 1993 0 0 21 .05338813 .4415 24.288 23.83263 6.884487 1 1994 0 0 21 .0517649 .4982 24.260313 24.02132 6.925595 1 1995 0 0 21 .0512402 .4797 24.43424 24.12565 6.891626 1 1996 0 0 21 .05364646 .4948 24.49408 24.197716 6.877296 1 1997 0 0 21 .071214095 .5006 24.58821 23.570583 6.877296 1 1998 0 1 21 .07117989 .4273 24.63981 24.2849 6.811244 1 1999 0 1 21 .07088037 .2614 24.971994 24.308714 6.684612 1 2000 0 1 21 .06271941 .8539 23.83033 24.40697 6.60665 1 2001 0 1 21 .055039 .556 24.485575 24.43152 6.638568 1 2002 0 1 21 .05649804 .5746 24.59655 24.464577 6.719013 1 2003 0 1 21 .05231318 .6055 24.62833 24.479 6.736967 1 2004 0 1 21 .05077323 .6867 24.570116 24.51651 6.694562 1 2005 0 1 21 .05311356 .5684 24.24638 24.55461 6.687109 1 2006 0 1 21 .05217143 .6056 24.36541 24.61615 6.708084 1 2007 0 1 21 .05387806 .6112 24.409815 24.66132 6.719013 1 2008 0 1 21 .05611051 .4473 24.828297 24.682966 6.747587 1 2009 0 1 21 .05811165 .4235 25.02365 24.699453 6.791222 1 2010 0 1 21 .0560264 .5767 24.86954 25.856627 6.700731 1 2011 0 1 21 .05059672 .5075 24.957836 25.90188 6.697034 2 1991 1 0 31 .4213557 .5093 23.51501 23.618286 6.692084 2 1992 1 0 31 .48241925 .5819 23.54186 23.73416 6.704414 2 1993 1 0 31 .48116615 .5178 23.475424 23.72624 6.098074 2 1994 1 0 31 .50073665 .6232 22.88424 23.50243 5.666427 2 1995 1 0 31 .5155886 .7512 20.85182 23.499 5.236442 2 1996 1 0 31 .49643224 .414 24.24684 24.96295 6.755769 2 1998 1 1 31 .4526372 .621 23.39155 25.00756 6.309918 2 2001 1 1 31 .2890171 .8521 23.21854 24.43679 6.161207 2 2002 1 1 31 .29551533 .1577 25.22541 24.481195 6.033086 2 2003 1 1 31 .27689195 .4164 24.090836 24.53496 5.993961 2 2005 1 1 31 .27040976 .2975 23.03234 24.59965 6.228511 2 2006 1 1 31 .27439922 .8709 22.373573 24.68687 6.204558 2 2007 1 1 31 .27405494 .2167 24.02231 24.60003 5.955837 2 2008 1 1 31 .28495467 1.3297 21.64143 24.623646 5.894403 2 2010 1 1 31 .2815831 .163 23.254734 24.68772 5.616771 2 2011 1 1 31 .3801102 .2409 22.92732 24.591793 5.575949 3 1991 0 0 47 .3354113 .6514 24.341873 25.25339 7.665753 3 1992 0 0 47 .34448385 .6793 24.276983 25.277357 7.597898 3 1993 0 0 47 .3559043 .7178 24.221666 25.326374 7.561642 3 1994 0 0 47 .3546242 .5764 24.515373 25.8834 7.580189 3 1995 0 0 47 .3592656 .5844 24.656904 25.90187 7.523481 3 1996 0 0 47 .3725042 .6432 24.53554 25.96245 7.441907 3 1997 0 0 47 .3836862 .5627 24.6562 25.91032 7.403061 3 1998 0 1 47 .3867261 .4604 24.79266 25.91152 7.428333 3 1999 0 1 47 .3996449 .5143 24.914743 25.9185 7.428333 3 2000 0 1 47 .33890685 .5777 24.857914 25.73189 7.342779 3 2001 0 1 47 .35462224 .6374 24.58293 25.729 7.265429 3 2002 0 1 47 .3785505 .551 24.82188 25.741364 7.290293 3 2003 0 1 47 .3876458 .6876 24.6553 25.74615 7.034388 3 2004 0 1 47 .40490225 .4178 23.212496 25.738005 7.013016 3 2005 0 1 47 .4127032 .1305 24.25599 25.74296 6.96319 3 2007 0 1 47 .4149574 .0746 25.330914 25.69178 6.790097 3 2009 0 1 47 .4066013 .1152 24.347645 27.203924 6.36647 3 2010 0 1 47 .4055971 .0626 24.98158 27.21099 6.284134 3 2011 0 1 47 .56482244 .086 24.43714 25.662464 6.385194 4 1991 0 0 71 .07956681 .3813 26.0167 26.762653 8.295548 4 1992 0 0 71 .0786362 .4794 25.95025 26.871416 8.250359 4 1993 0 0 71 .07177163 .4826 25.891724 27.022476 8.230044 4 1994 0 0 71 .07273845 .5245 25.830635 27.25725 8.209309 4 1995 0 0 71 .07342871 .4993 26.233444 27.39054 8.167352 4 1996 0 0 71 .072934516 .5574 26.03198 27.40442 8.1847925 4 1997 0 0 71 .0781921 .4979 26.245274 27.45299 7.988882 4 1998 0 1 71 .07776387 .3591 26.248676 27.372503 7.935945 4 1999 0 1 71 .07633055 .3336 26.288864 27.38952 7.806289 4 2000 0 1 71 .07649403 .3717 26.308447 27.410067 7.767264 4 2001 0 1 71 .068164214 .3247 26.244555 26.23344 7.082549 4 2002 0 1 71 .067267805 .3011 26.00619 26.29709 7.102499 4 2003 0 1 71 .073163316 .3953 25.76795 26.386675 7.082549 4 2004 0 1 71 .0745528 .2468 25.72853 26.43069 7.118826 4 2005 0 1 71 .071113676 .2641 25.79058 26.47537 7.154615 4 2006 0 1 71 .07161281 .3372 25.542967 26.55257 7.132498 4 2007 0 1 71 .07922857 .3959 25.32298 26.59785 7.081708 4 2008 0 1 71 .12331319 1.656 22.990234 26.64 7.096721 4 2009 0 1 71 .104891 .232 25.93053 26.667366 7.074963 4 2010 0 1 71 .09211212 .1768 26.10226 26.703707 7.06732 4 2011 0 1 71 .10922042 .0841 25.3756 22.850906 5.135798 5 1991 1 0 11 .5145179 .3402 25.092907 24.887163 7.467942 5 1992 1 0 11 .5063352 .5111 24.785185 25.157526 7.511525 5 1993 1 0 11 .4772263 .4148 25.13526 25.329826 7.501082 5 1994 1 0 11 .484674 .3457 25.403194 25.788897 7.627544 5 1995 1 0 11 .4526424 .4394 25.52822 25.86832 7.64874 5 1996 1 0 11 .4169289 .4654 25.59211 25.928566 7.699389 5 1997 1 0 11 .4172299 .3858 25.712555 25.899134 7.596894 5 1998 1 1 11 .406155 .2884 25.81511 25.92809 7.504392 5 1999 1 1 11 .3698842 .2843 25.918396 25.915674 7.418781 5 2000 1 1 11 .4236287 .1593 26.647585 26.037374 7.567863 5 2001 1 1 11 .4423804 .454 25.84178 26.04502 7.648263 5 2002 1 1 11 .4422717 .6478 25.58613 26.165104 7.60589 5 2009 1 1 11 .4075448 .2534 26.251715 26.52544 7.373374 5 2010 1 1 11 .4097762 .3394 26.20202 26.55831 7.366445 5 2011 1 1 11 .444746 .3654 26.318483 28.21211 8.131236 6 1991 0 0 21 .05181734 .669 24.20566 23.935875 7.337588 6 1992 0 0 21 .05352982 .6757 24.288904 24.07287 7.338888 6 1993 0 0 21 .05338813 .6775 24.334217 24.136194 7.312553 6 1994 0 0 21 .0517649 .701 24.371475 24.19478 7.273093 6 1995 0 0 21 .0512402 .6769 24.532085 24.280895 7.257003 6 1996 0 0 21 .05364646 .7363 24.456446 24.355743 7.26333 6 1997 0 0 21 .071214095 .6192 24.613295 25.07311 7.161622 6 1998 0 1 21 .07117989 .3821 24.895733 25.081173 7.028202 end
