On Thu, 15 Jun 1995 [EMAIL PROTECTED] wrote:


> But the point still holds: if one replaces Marx's simplifying 
> assumption with a demonstrably market-relevant condition (long-run 
> wages constant at the subsistence level), there is no "tendency" for 
> the rate of profit to fall--and this is a useful result. Gil

Gil, apparently we have a somewhat different reading of this section of 
the third volume of Capital.  The only place I find Marx suggesting that 
technical change is itself a causative agent of falling profits is in a 
brief passage in his supplementary remarks at the end of the section.  
Here, Marx makes it quite clear that the effects of technical change 
on profits cannot be understood outside of the changes they create in 
prices and quantities, which Okishio entirely fails to do.  

In any event, this passage (which I don't think is true in as much 
generality as Marx stated it -- but more on that later) was not central 
to Marx's exposition of the "law," during most of which technical change 
is listed as a counteracting factor either through the more intense 
exploitation of labor or through the cheapening of the elements of 
constant capital.  

To my mind, the most straight-forward justification for the fall in the 
rate of profit is this: 

"If we further assume now that this gradual change in the composition of 
capital [from variable toward constant capital -- TB] does not just 
characterize certain individual spheres of production, but occurs 
in more or less all spheres, or at least the decisive ones, and 
that it therefore involves changes in the average organic 
composition _of the total capital belonging to a given society_, 
[my emphasis -- TB] then this gradual growth in the constant capital, in 
relation to the variable, must necessarily result in a _gradual fall in 
the general rate of profit_, [e.a.i.o.] given that the rate of surplus 
value, or the level of exploitation of labor by capital, remains the same."

[this is the third paragraph of the "part."  I'm using the 1981 Vintage 
edition.]

Marx then proceeds to say about ten sentences later (same paragraph,as is 
his habit :)  ) that the fall "is just another expression for the 
progressive development for the social producitivity of labor, which is 
shown by the way that the growing use of machinery and fixed capital 
generally enables more raw and ancillary materials to be transformed into 
products in the same time by the same number of workers, i.e., with less 
labor."

I think this may be where the excessive attention to technical change 
comes from; however, note that there is nothing in this passage (nor the 
few subsequent passages in this section making similar claims) that Marx 
is actually talking about an individual capitalist coming up with a new 
technique.  He purposefully uses the phrase "social productivity of 
labor" (I'd be curious to know what the German is.  Justin?)  and, in the 
passage I just quoted before this, in the clause that I emphasized, 
refers to the increase in constant capital belonging to a total society.

In other words, these are social phenomena and do not necessarily reflect 
CU-LS productivity enhancements by individual capitalists, even if these 
may be the type of enhancements most commonly made.  Rather, the 
phenomenon is that:

(1) capitalists accumulate capital, and most of this capital is 
reinvested.  This creates an increase in the social capital stock.

(2) Marx then goes through a number of examples that demonstrate the 
effects of diminishing marginal returns to capital (he doesn't use the 
word anywhere, but I think the shoe fits pretty well) under various 
assumptions about the rate of expolitation.  Basically, diminishing 
marginal returns, assuming a constant rate of exploitation (or even a 
constant real wage, or even a zero wage for that matter, as an example 
will illustrate below, though Marx never shows this), mean that 
the additional capital investments yield less surplus value than their 
predecessors, thereby also bringing down the average rate of return, 
i.e., the average profit.  [Someone may argue that the concept of "marginal 
returns" requires institutional assumptions about the value of factors, 
but it's pretty clear to me that these assumptions are made once either 
the wage or the rate of exploitation is assumed constant and a production 
function is specified.]

During all this, of course, labor is becoming more productive because it 
has more and more capital to work with.  Needless to say, this is not the 
same thing as technological change.

In the next chapter, Marx goes through the various reasons why profits do 
not in fact always fall, arguing that technical improvements will offset 
the fall through increased exploitation and commodity cheapening. I see 
Okishio's theorem as largely consistent with Marx, particularly when Marx
states (this is actually in the third chapter, a bit into section two, 
page 356 in my edition):

"A rise in productivity... can increase the magnitude of the capital only 
if it increases the part of the annual profit that is transformed back 
into capital, by raising the rate of profit.  In so far as labor 
productivity is concerned, this can come about (since this productivity 
is not directly relevant to the _value_ of the existing capital) only in 
so far as it involves either a rise in relative surplus value or else 
reduces the value of constant capital, in other words cheapens the 
commodities that go into the reproduction of labor-power or the elements 
of constant capital."

Of course the assumptions here are different: constant rate of surplus 
value (i.e., wages growing at the rate of productivity) in Marx's case 
vs. constant real wage in Okishio's.  However, a constant real wage does 
not preclude falling profits.


Let me turn around and go totally neoclassical for a minute, in order to 
illustrate this with a particular example.

Suppose aggregate production is described by a Cobb Douglas function, 
f=k^a * l^(1-a).  Suppose labor supply is fixed at 1.  Suppose there is a 
capitalist class that owns capital stock k(0) at time zero and that 
profits get reinvested into the capital stock.  

Suppose k(0) = 1.  Then, assuming the silly old marginal product laws, 
labor gets paid (1-a) * k(t)^a, i.e., a constant fraction (1-a)/l of output.
Therefore this is consistent with a constant rate of exploitation even if 
it's not the best justification for it. Capital accumulates according to the 
differential equation dk = a*k(t)^a, which I'm sure is simple but I 
don't feel like solving it right now.  In any event, it's always positive 
and total capital is always increasing.  The profit rate at any given 
point, from marginal conditions, is equal to a*k(t)^(a-1), which goes to 
zero as k(t) increases to infinity.

On the other hand, assuming a constant real wage, capital accumulates 
according to the function dk/dt = k(t)^a*l^(1-a) - wl (= k(t)^a - wl), 
which again is always increasing.  Here, the profit rate is equal to 
[k(t)^a*l^(1-a) - wl]/k(t), i.e., it's converges asymptotically to 
k(t)^a-1, which is larger than in theMP case only by a constant factor and 
goes to zero as the capital stock increases.

It would not be hard to show, in this example, that if productivity were 
growing at the same rate as capital (whatever the solution to that damned 
diff eq is in front of the other coefficients) that the profit rate would 
be constant.  This merely illustrates the one side of the story of 
technical change and accumulation that Okishio considers.

Of course the above example is of fairly limited relevance to actual 
accumulation, (1) because it doesn't take into account the effects of 
wages on consumption and (2) because the innovations are both Harrod- and 
Hicks-neutral, which don't seem, in general, to describe the real world.  
I'm not going to address (1) now, but I think Marx does provide an 
important response to (2), which was followed up on By Shaikh in respnse 
to Okishio [Marx does also provide a good response to (1) that I think is 
very under-studied, but it would double the length of this post to 
discuss it and I'm already eating up time and bandwidth.  I think the 
question of CU-LS technical changes creating lower profits is usually
justified from the following passage: 

"No capitalist voluntarily applies a new method of production, no matter 
how much more productive it may be or how much it might raise the rate of 
surplus value, if it reduces the rate of profit.  But every new method of 
this kind makes commodities cheaper.  At first, therefore, he can sell 
them above their prices of production, above their value.  He pockets the 
difference between their costs of production and the market price of 
other commodities, which are produced at higher production costts.  This 
is possible because the average socially necessary labor time required to 
produce these latter commodities is greater than the labor time required 
with the new method of production.  His production procedure is ahead of 
the social average.  But competition makes the new procedure universal 
and subjects it to the general law.  A fall in the profit rate then 
ensues..."

The general story, then, is that the capitalist adopts the new method of 
production that creates higher profits than before during, say, period 
1, and then lower profits than before during, say, period 2.  I think 
there are a number of expectational considerations in determining whether 
or not the capitalist would want to do this.  Taking the individual 
capitalist as the sole agent, this could only happen by way of accident, 
since it's hard to believe that an entrepreneur would undertake an 
activity that would lower the expected future profits or else be fooled 
persistently into thinking those profits were higher than they actually 
were.  

On the other hand, looking at interactive behavior, things could go 
either way depending on expectations (i.e., dynamic strategies), for 
which the Folk Theorem says pretty much anything interesting goes.  
Successfully choosing not to make an innovation might happen in more 
mature markets where entrepreneurs are more sure of their competitors' 
profits versus newer markets (e.g., computers) where somebody is bound to 
enter the market with the new technology fairly soon.

In any event, in the latter case (which I would argue is probably more 
the norm; few markets are entirely fixed from entry) I think it's pretty 
straight forward to illustrate Shaikh's response to Okishio with a 
Cournot example (for which Shaikh with his aversion to anything vaguely 
neoclassical would be none too happy).  I'm trying to use "reasonable" 
numbers here.

Suppose two firms face a demand function p = 10 - q and two possible 
technologies with constant marginal costs 5 and 2.5.  Ignore sunk costs 
for a second.  The Cournot equilibrium for the first technology is q = 
5/3 for each firm, p = 6 2/3, and each firm has profits 2 7/9.  In the 
second case, q = 2 1/2, p = 5, and each firm has profits 6 1/4.

(the "reasonableness" so far is that the price elasticity of demand at 
the relevant point is just over 1, which is a little high but actually then 
only underscores the point since a lower elasticity would strengthen
the effect.  The thing I like about the two-player Cournot example is 
that it puts the individual firm's elasticity at about twice that of the 
aggregate elasticity, which seems ballpark right to me though I don't 
know of studies of this kind of stuff).

Now, back to the sunk costs: Suppose all marginal costs are labor and all 
sunk costs are capital (it doesn't really matter for the Marxian 
questions since they are, by definition, variable and constant capital).
Each firm would be willing to just over double its capital costs in order 
to maintain the same profit rate.  Given that each firm raises its output 
by fifty percent, this seems excessive but not too excessive.  I'm sure 
moving the elasticity up would create a 1-1 increase or even less in the 
break-even case. 

I do think this kind of game is a lot more reasonable than the typical 
neoclassical functions that Okishio considers for a couple of reasons: 
(1) innovations more typically involve larger sunk costs and smaller 
marginal costs and (2) firms have a bit of room to manoever their prices 
as well as get into price wars or not get into them.  The point is not 
that changes under these conditions _always_ lower the profit rate, but 
that under very reasonable specifications they may.

Either way, it illustrates Marx's point pretty well: I leave it to the 
reader :) :) to show that in the break-even case (i.e., the same profit 
rate in the two scenarios), the firm that stays with the higher-MC 
technology while the other one switches will get really screwed.  I 
haven't done the math but it seems pretty intuitive and not hard to 
compute just annoying.  If a firm believes that it can switch 
technologies a "period" before its competitors do anyway, then the 
incentives will be that much greater.  So expectational considerations 
can go a long way toward lowering the profit rate.

In any event, I don't think this is the main justification for falling 
profits.  Technical change seems to be correlated with higher profits, 
though I don't know of studies of this on a firm-level basis, with 3-5 
year lags and using more "Marxian" estimates of these variables.  But 
it does raise serious questions about the relevance of Okishio's theorem,
even within the one side of the story of accumulation that it does address.

Added to this, Gil, if there is no tendency of the profit rate to fall, why 
has it been on a downward trend for the last 25 years or so?


Yours for the squabble after the revolution,
Tavis

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