Andrew Farrant wrote: Hayek does buy the dreadful Misesian cumulative   
'logic of intervention' argument though right?  
  
"It is not necessary to review the familiar economic arguments which show   
why mere 'interventionism' is self-defeating and self-contradictory, and   
how, if the central purpose of intervention is to be achieved,   
intervention must expand until it becomes a comprehensive system of   
planning" (Hayek [1939] 1997, pp.199-200).   
  
Bruce Caldwell replies:  
  
Andrew quotes from "Freedom and the Economic System," a policy pamphlet   
that laid the groundwork for the arguments in The Road to Serfdom. In his   
pamphlet, Hayek footnotes a book by Mises (his Kritik des   
Interventionismus) - the footnote being  attached to the sentence Farrant   
reproduces. Neither the statement that Hayek made in the 1939 piece, nor   
any reference to this work by Mises, appears in The Road to Serfdom,   
though Hayek does list two other books by Mises (Socialism and Omnipotent   
Government) in his list of books he recommends to the reader.   
  
One conclusion that one might draw from this is that Hayek reconsidered   
this argument, and therefore did not include it in The Road to Serfdom. In   
any event, that was the book that Doug was talking about.   
  
Bruce Caldwell