Hi All,


I have two unbalanced panel dataset with different variables in different frequencies. The first one has annual data with time periods 1980, 1990, 2000, and 2010, as shown below.

Code:
fipsmerg    cntynm    stateab    year    totpop    reltrad    adherent
1001    Autauga County    AL    1980    32259    Protestant    15796
1001    Autauga County    AL    1980    32259    Catholic    43
1001    Autauga County    AL    1980    32259    Other    200
1001    Autauga County    AL    1990    34222    Catholic    1025
1001    Autauga County    AL    1990    34222    Protestant    22361
1001    Autauga County    AL    1990    34222    Other    323
1001    Autauga County    AL    2000    43671    Catholic    1490
1001    Autauga County    AL    2000    43671    Other    465
1001    Autauga County    AL    2010    54571    Protestant    38480
1001    Autauga County    AL    2010    54571    Other    856
1001    Autauga County    AL    2010    54571    Catholic    1766
1003    Baldwin County    AL    1980    32259    Protestant    19796
1003    Baldwin County    AL    1980    32259    Catholic    435
1003    Baldwin County    AL    1980    32259    Other    900
1003    Baldwin County    AL    1990    34222    Catholic    600
1003    Baldwin County    AL    1990    34222    Protestant    29000
1003    Baldwin County    AL    1990    34222    Other    300
1003    Baldwin County    AL    2000    43671    Catholic    1100
1003    Baldwin County    AL    2000    43671    Other    500
1003    Baldwin County    AL    2010    54571    Protestant    41000
1003    Baldwin County    AL    2010    54571    Other    900
1003    Baldwin County    AL    2010    54571    Catholic    1800

The second has annual data, as shown below. This time range is 1975-2015

Code:
gvkey    datadate          fyear
001004    31may1976    1975
001004    31may1977    1976
001004    31may1978    1977
001004    31may1979    1978
001004    31may1980    1979
001004    31may1981    1980
001004    31may1982    1981
001004    31may1983    1982
001004    31may1984    1983
001004    31may1985    1984
001004    31may1986    1985
001004    31may1987    1986
001004    31may1988    1987
001004    31may1989    1988
001004    31may1990    1989
001004    31may1991    1990
001004    31may1992    1991
001004    31may1993    1992
001004    31may1994    1993
001004    31may1995    1994
001004    31may1996    1995
001004    31may1997    1996
001004    31may1998    1997
001004    31may1999    1998
001004    31may2000    1999
001004    31may2001    2000
001004    31may2002    2001
001004    31may2003    2002
I first aim to generate years between the decades (linearly interpolate), such that i can merge it with the second dataset.
Can someone please help me with the code? I aim for something like the following, which I found here .

Code:
expand 10
bys fipsmerg year: replace totpop=. if _n!=_N
by fipsmerg: gen year_new=_n
by fipsmerg: ipolate totpop year_new, gen(y_pop) epolate
by fipsmerg year: replace year_new=_n
Yet, i need interpolated years, totpop, and adherent, rather than only totpop as is in the code above.

Thanks in advance!