STATA-FORUM.DE

Dear all,

I have time series for 3 stock portfolios ("0","5" and "10") with data for R&D spending ("pfxrd") and portfolio return ("pfrt"). For each Portfolio ("pf") I want to calculate the average portfolio return over ten years following the initial year of R&D spending. I will provide the data and elaborate a bit more on it then:

Code: Alles auswählen

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(year pf pfxrd pfrt)
1962 0         0  2.0433624
1963 0         0   3.235416
1964 0         0  2.0289717
1965 0         0   4.715116
1966 0       .77   2.840973
1967 0       .48    .876097
1968 0      1.41  2.4592624
1969 0      7.08  -.6605892
1970 0         0   .4436268
1971 0         0   2.881102
1972 0         0  1.0571196
1973 0         0  -3.090473
1974 0         0 -2.3816926
1975 0         0   5.344191
1976 0         0   2.180875
1977 0      4.44   .6919739
1978 0     6.248   1.340753
1979 0     8.422  2.3498313
1980 0    12.246   3.059075
1981 0    13.362   .8223675
1982 0    19.994  4.2377257
1983 0    34.747  2.1897767
1984 0    49.399 -.07765996
1985 0    54.386   2.788236
1986 0   109.911  1.9860017
1987 0   296.832   1.192912
1988 0  7507.789   2.677546
1989 0  7573.345  1.8918866
1990 0  8001.991   .7434589
end
format %ty year


Example: In 1966 the R&D spending of portfolio 0 was .77. I would like to get the portfolio return for 1 year after that date, 2 years after that date,....and 10 years after that date. This should be done for each portfolio and each year where R&D spending is positive. After that I would like to calculate the mean values of those returns for 1-10 years after R&D spending. Can anybody provide some advice, please?

Any help is much appreciated.

Best,
Alex

In 1966 the R&D spending of portfolio 0 was .77. I would like to get the portfolio return for 1 year after that date, 2 years after that date,....and 10 years after that date. This should be done for each portfolio and each year where R&D spending is positive.