我试图合并两个data.frames,它们如下所示:
GVKEY YEAR coperol delta vega firm_related_wealth
1 001045 1992 1 38.88885 17.86943 2998.816
2 001045 1993 1 33.57905 19.19287 2286.418
3 001045 1994 1 48.54719 16.85830 3924.053
4 001045 1995 1 111.46762 38.71565 8550.903
5 001045 1996 1 218.89279 45.59413 17834.921
6 001045 1997 1 415.61461 51.45863 34279.515
和
GVKEY YEAR fracdirafter fracdirafterindep twfracdirafter
1 001004 1996 1.00 0.70 1.000000000
2 001004 1997 0.00 0.00 0.000000000
3 001004 1998 0.00 0.00 0.000000000
4 001004 1999 0.00 0.00 0.000000000
5 …