Derivation
variable: prefrest3 [decade estimate of previous village start] table[s]: tb_tbx, tb_tbxto2007, tbold_part1/2, tb_tbo, tb_tboto2007, tbold_control)
variable: prefrmm3 [month of previous village start] (table[s]: tb_tbx, tb_tbxto2007, tbold_part1/2, tb_tbo, tb_tboto2007, tbold_control)
variable: prefryear3 [year of previous village start] (table[s]: tb_tbx, tb_tbxto2007, tbold_part1/2, tb_tbo, tb_tboto2007, tbold_control)
recode prefrmm3 0=1
replace prefryear3=1895 if prefrest3==1
replace prefryear3=1905 if prefrest3==2
replace prefryear3=1915 if prefrest3==3
replace prefryear3=1925 if prefrest3==4
replace prefryear3=1935 if prefrest3==5
replace prefryear3=1945 if prefrest3==6
replace prefryear3=1955 if prefrest3==7
replace prefryear3=1965 if prefrest3==8
replace prefryear3=1975 if prefrest3==9
replace prefryear3=1985 if prefrest3==10
replace prefryear3=1995 if prefrest3==11
replace prefryear3=1895 if prefrest3==12
replace prefryear3=1907 if prefrest3==13
replace prefryear3=1924 if prefrest3==14
replace prefryear3=1940 if prefrest3==15
replace prefryear3=1951 if prefrest3==16
replace prefryear3=1960 if prefrest3==17
replace prefryear3=1970 if prefrest3==18
recode prefryear3 9999=. 0=.
gen prefrdate3=mdy(prefrmm3,15,prefryear3) if prefrmm3~=. & prefryear3~=.
replace prefrdate3=mdy(6,15,prefryear3) if prefrmm3==. & prefryear3~=.
