name of dataset: okun
no of variables: 4
no of observations: 47

+----------+-------------------------------+
| variable | label                         |
+----------+-------------------------------+
| year     | 1959 through 2005             |
| pcrgdp   | percentage change in real GDP |
| unem     | civilian unemployment rate    |
| cunem    | unem - unem[_n-1]             |
+----------+-------------------------------+

Economic Report of the President, 2007, Tables B-4 and B-42.