How to generate a new variable as a non-algebraic combination of values

[Chul-Kyoo Jung]

Hi, I have the following data and v6 has years and v7 has months.
I want to overwrite v6 whose value should be like 6101, meaning year 1961 and January, 7703, meaning 1977 March, and so on.
Could you help?

* Example generated by -dataex-. To install: ssc install dataex
clear
input float v6 int v7
   .  .
   .  .
   .  .
1961  1
1977  3
1999  1
   .  .
   .  .
   .  .
1983  5
2000  3
2000  6
2001  4
   .  .
1953  9
1956 11
1957  6
1962  5
1964  7
1966  6
1969  5
1971  6
1973  4
1973  5
1981  4
1982  6
1983 12
1986  1
1988  1
1988  8
1989  1
1989 12
1991  6
1991  6
1992  6
1993 10
1993 12
1993  6
1993  8
1994 10
1995 10
1995  3
1995  6
1995  8
1996 12
1996  4
1996  6
1997 10
1999  1
1999  1
1999 10
1999  3
1999  4
2000  1
2000 10
2000 10
2000 12
2000  4
2001  4
2001  5
2001  7
2002  1
2002 12
2002  3
2002  5
2002  8
   .  .
   .  .
   .  .
   .  .
   .  .
1976  6
1986 10
1989  4
   .  .
   .  .
1926 10
1984  3
1992 11
1992  5
1994  8
1997  8
2001  2
   .  .
   .  .
   .  .
   .  .
   .  .
   .  .
   .  .
   .  .
   .  .
   .  .
   .  .
   .  .
1952 11
1953  5
1972  4
1973 10
1974  4
end

[Clyde Schechter]

gen yy = mod(v6, 100)
egen wanted = concat(yy v7), format(%02.0f)

will do this.

All of that said, unless you have to do this so you can link this data set with some other data set that has coded its monthly dates in this way, this is a terrible idea. You cannot do arithmetic with this kind of representation of dates. For example, 7401 - 7312 is 89, even though Jan 74 is just one month after Dec 73. If you are going to do any calculations with dates, you must use Stata internal format date variables:

gen mdate = ym(v6, v7)
format mdate %tm

[Chul-Kyoo Jung]

Clyde Schechter Thank you so much!