Did, psm ๅ did+psm ๆไฝๅทฎๅผ๏ผ did ่ฆๅๅฎไธๅฏ่งๆตๆๅบ้ๆถ้ดๅๅ่ถๅฟ็ธๅ๏ผ @ๆ ง่ช ๆพ็คบๅ จ้จ ๅ ณๆณจ่ 784 ๆฌๆไป็ป็ๆฏไบไปถ็ ็ฉถๆณ (event study) ๅจ stata ไธญ็ๅฎ็ฐๅฝไปค eventdd๏ผ่ฏฅๅฝไปค็ฑ damian clarke ๅ kathya tapia schythe ๅจ 2020 ๅนดๅ ฑๅๅผๅใไธไปฅๅพๅ ณไบไบไปถ็ ็ฉถๆณ็ไป็ปไธๅ๏ผๆฌๆๅฐไพง้ไบ่ฟ็งๆนๆณๅจๅๅๆณๅนณ่ก่ถๅฟๆฃ้ชไธญ็ๅ ทไฝๅบ็จใ ็ธๅ ณ็่ฎบ ไบไปถ็ ็ฉถๆณๆฏไธ็งไธๅๅๆณ (did) ็ธ็ฑปไผผ็้ขๆฟไบไปถ็ ็ฉถๆนๆณ.