I would be interested in some speculations about why economics has taken 
an empirical direction.

I don't doubt that the NBER has played a positive role by providing 
congenial forums in which empirical economists can exchange ideas and in 
other ways. However, my assumption would be that the main force has been 
the tremendous fall in the cost of computing. It  is much much easier to 
compile and manipulate  large data sets than it was 25 or 30 years ago.  
The funding agencies  may also have played a role.  My impression is 
that NSF and NIH favor projects that collect and make available large 
data sets. And there have been some developments in econometrics (VARs) 
that are data intensive. But, of course, the development of 
data-intensive econometric techniques is partly the result of the fall 
in computing costs.

Hugh Rockoff