A-=1103 Wien Postfch 91 
13th June 1976 
Dear Dr Gomulka, 
Thankyou very much for your letter and the manuscript. 
In the meantime I have come to see a new aspect of the matter. 
In fact, Kalecki never used the mixed difference-differential 
equation with the forward argument which you attribute to him 
After the first version of 1935 he always used finite differences only. 
Now you may say this comes to the same if the differences are small 
( the unit of time, that is ). However, I have come to the conclusion 
that he did not mean the differences i.e. the unit of time, to be small. 
This is perfectly clear just in the paper which you use as a starting 
point for your discussion, the 1962 paper. The unit of time is there 
equal to the lag, and he writes 
I,,, = alt + bAI, 
3ince we must reasonably interpret 
the equation will be 
I ,o - (a+b) Ig4yq +B Ig = 
This is no dout a simplification, and the time unit more generally 
may be different, but i$ is clear that it should be not small. 
ln fact, it would be absurd to assume anything else; 
it would mdan assuming that the changes in profit from one day to the 
other influence the investment dgcisions. Realisticlaly you must assume 
that the investor wall wait zmzx some time and decide then only whether 
ond how much profits have increased; this time may be a year or 1t 
may be less, hardly less then half. or a quarter of a year. 
If you assume such a finite differencefor the increase in 
profits, all the absurdities which I talked about in my last two letters 
do not exist any more. The short time ups and downs of profits will 
anter the investment decision only after they have been smoothed out. 
The minor cycles which will exist to take account of a finiet span 
of initial conditions cannot have, in the case of the difference 
squation . an anti-damping if the major cycle is damped.