Number of Strikes, 108 Observations in 9 years, 1968-1976 
Source: Kennan (1985). 
date = month in which strikes occurred
n = number of strikes that began that month 
Prod = Unanticipated output.

   Number of strikes as a function the deviation of output from its trend level,
   an indicator of the business cycle position of the economy.  
   The data was originally analyzed by J. Kennan (1985) in
   his paper "The Duration of Contract Strikes in U.S. Manufacturing," Journal of 
   Econometrics, 28, 55 - 28.