. webuse gxmpl1, clear
. set more off
. list
+-----------------------+
| year cpi gnp |
|-----------------------|
1. | 1989 124 5837.9 |
2. | 1990 130.7 6026.3 |
3. | 1991 136.2 6367.4 |
4. | 1992 140.3 6689.3 |
5. | 1993 144.5 7098.4 |
|-----------------------|
6. | 1994 148.2 7433.4 |
7. | 1995 152.4 7851.9 |
8. | 1996 156.9 8337.3 |
+-----------------------+
. gen dcpi = D.cpi
(1 missing value generated)
. list
+----------------------------------+
| year cpi gnp dcpi |
|----------------------------------|
1. | 1989 124 5837.9 . |
2. | 1990 130.7 6026.3 6.699997 |
3. | 1991 136.2 6367.4 5.5 |
4. | 1992 140.3 6689.3 4.100006 |
5. | 1993 144.5 7098.4 4.199997 |
|----------------------------------|
6. | 1994 148.2 7433.4 3.699997 |
7. | 1995 152.4 7851.9 4.199997 |
8. | 1996 156.9 8337.3 4.5 |
+----------------------------------+
|