March 11, 1985 
Dear Sandro, 
Thank yon for your kind letter. As you cstrt see from the 
enclosed paper I have made use of your comments•which have 
helped ne a lot. The only thing which I cannot follow and which 
puzzftes me is your argument in the earlier letter ( illustrated 
by a graph ) in which you bring in wage rate and interest 
in order to undermine the validity of (ray use of ) ft as a measure 
of productivity ( of course it is not the ‘productivity of 
labour). Sraffa was dll along striving at measures invariant 
w.r.t. distribution, so why should you drag in particular wage 
and interest rates into the discussion of this measure? 
We must somehow be talking at cross purposes, it may well be 
that I completely miss your point. 
lour BNL paper on Staffs was published inthe Wiener Zeitung 
( an official daily paper with a weekly kind of literary 
supplement) so your visit has left plenty of traces! 
Kind regards, 
lours 
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