Code:
gen geo3= geo3_bd2001
gives the following values. I wonder what might cause this. Any idea please? Thank you.

geo3_bd2001 geo3
10079076 10079076
10079080 10079080
10079087 10079087
20003004 20003004
20003014 20003014
20003051 20003052
20003073 20003072
20003089 20003088
20003091 20003092
20003095 20003096