1.0 Introduction
Over a half-century ago, economists reached a consensus. The model in which employment
and real wages are explained by the intersection of a downwards-sloping labor
demand function and a supply function is incoherent, not even wrong.
This incoherence was demonstrated under the assumptions of perfect competition
and of firms that have adjusted their plant and other capital
inputs. I do not know what Greg Mankiw
and Jonathan Gruber
are doing, but it certainly is not education.
Anyways, I have not recently gone through a simple example, without some of my innovations.
Maybe I will repost this some time with graphs and more references.
2.0 Technology
Consider a very simple vertically-integrated (representative) firm that produces a
single consumption good, corn, from inputs of labor, iron, and (seed)
corn. All production processes in this example require a year to
complete. The managers of the firm know of two processes for producing corn
and two processes for producing iron.
The processes A and B, for producing corn, require the tabulated inputs
to be available at the beginning
of the year for each bushel corn produced and available at the end of
the year. Similarly, process C, for example, requires one person-year, 1/40 bushels corn,
and 1/10 tons iron to be available at the beginning of the year for each ton of iron produced
by this process. This is an example of circulating capital; all inputs of corn and iron are used up during
the year in producing the gross output.
Table 1: Coefficients of Production
Input | Industry |
Corn | Iron |
A | B | C | D |
Labor | a0, 1(A) = 1 | a0, 1(B) = 1 | a0, 2(C) = 1 | a0, 2(D) = 275/464 |
Corn | a1, 1(A) = 2/5 | a1, 1(B) = 3/5 | a1, 2(C) = 1/40 | a1, 2(D) = 0 |
Iron | a2, 1(A) = 2 | a2, 1(B) = 1/2 | a2, 2(C) = 1/10 | a2, 2(D) = 113/232 |
Apparently, inputs of iron and corn can be traded off in producing
corn outputs.
Likewise, inputs of corn and iron can be traded off in producing iron. The iron-producing
process that uses less iron and more corn, however, also requires
a greater quantity of labor input.
2.0 Techniques
A technique consists of a process for producing corn and a process
for producing iron. Thus, there are four techniques in this example.
They are defined in Table 3.
Table 2: Techniques of Production
Technique | Corn Process | Iron Process |
Alpha | A | C |
Beta | A | D |
Gamma | B | C |
Delta | B | D |
3.0 Quantity Flows
I want to consider a couple of different levels at which this
firm can operate the processes comprising the techniques. First,
consider the quantity flows in Table 3, in which Process A is used to produce 1 41/49 Bushels corn, and
Process C is used to produce 4 4/49 Tons iron.
When the firm operates these processes in parallel, it requires
a total of 41/49 bushels corn as input. The output of the
corn-producing process can replace this input, leaving a net
output of one bushel corn. Notice that the total input of
iron are 3 33/49 + 20/49 = 4 4/49 tons iron, which is exactly
replaced by the output of Process C. So Table 4 shows a technique
in which 5 45/49 person-years labor are used to produce a net
output of one bushel corn. The firm, when operating this technique
can produce any desired output of corn by scaling both processes
equally.
Table 3: The Alpha Technique
Inputs | Process A | Process C |
Labor | a0, 1(A) qA = 1 41/49 person-yrs. | a0, 2(C) qC = 4 4/49 person-yrs. |
Corn | a1, 1(A) qA = 36/49 bushels | a1, 2(C) qC = 5/49 bushels |
Iron | a2, 1(A) qA = 3 33/49 tons | a2, 2(C) qC = 20/49 tons |
Outputs | qA = 1 41/49 bushels | qC = 4 4/49 tons |
Table 5 shows the application of the same sort of arithmetic to
the Beta technique. The labor-intensity of the Beta technique is 5 185/357 person-years per bushel.
Neither the Gamma nor the Delta technique are profit-maximizing
for the prices considered below.
Table 4: The Beta Technique
Inputs | Process A | Process D |
Labor | a0, 1(A) qA = 1 2/3 person-yrs. | a0, 2(D) qD = 3 304/357 person-yrs. |
Corn | a1, 1(A) qA = 2/3 bushels | a1, 2(D) qD = 0 bushels |
Iron | a2, 1(A) qA = 3 1/3 tons | a2, 2(D) qD = 3 59/357 tons |
Outputs | qA = 1 2/3 bushels | qD = 6 178/357 tons |
4.0 Prices
Which technique will the firm adopt, if any? The answer
depends, in this analysis, on which is more profitable. So one
has to consider prices. I assume throughout that inputs of iron,
corn, and labor are charged at the start of the year. Corn is
the numeraire; its price is unity throughout. Two different
levels of wages are considered.
4.1 Prices with a Low Wage
Accordingly, assume wages are initially 3/2780 bushels per
person-year. Under the assumptions of perfect competition,
this price of labor is a given for the firm.
If all corn-producing
firms are vertically integrated, a market price for iron is not
available. At the end of the year, the firm will have a stock of
produced corn and iron. Even though the managers of the firm intend all of
the iron to be used as an input to further production, the question
arises for accountants of how to evaluate the stock of gross output.
I suggest the accountants set a price of iron such that the firm
is making the same rate of profits in all of the processes
that it is operating. According let the price of iron, p,
be 55/1112 bushels per ton.
Table 5 shows accounting with these prices. The column labeled
"cost" shows the cost of the inputs needed to produce one unit
output, a bushel corn or a ton iron, depending on the process.
Accounting profits for a unit output are the difference between
the price of a unit output and this cost. The rate of (accounting)
profits, shown in the last column, is the ratio of accounting
profits to the cost. The rate of profits is independent of
the scale at which each process is operated.
Table 5: Costs and the Rate of Profits at a Low Wage
Process | Costs | Rate of Profits |
A | a1, 1(A) + a2, 1(A) p + a0, 1(A) w = 1/2 | 100 percent |
B | a1, 1(B) + a2, 1(B) p + a0, 1(B) w = 6959/11120 | 59.8 percent |
C | a1, 2(C) + a2, 2(C) p + a0, 2(C) w = 69/2224 | 59.4 percent |
D | a1, 2(D) + a2, 2(D) p + a0, 2(D) w = 55/2224 | 100 percent |
These prices are compatible with the use of the Beta technique
to produce a net output of corn. The Beta technique specifies that
process A be used to produce corn and process D be used to produce
iron. Notice that process B is more expensive than process A, and
that process C is more expensive than process D. These prices do
not provide signals to the firm that processes outside the Beta
technique should be adopted. The vertically-integrated firm is
making a rate of profit of 100 percent in producing corn with the Beta
technique. The same rate of profits are earned in producing corn
and in reproducing the used-up iron by an iron-producing process.
4.2 One Set of Prices with a Higher Wage
Suppose this firm faces a wage more than 25 times higher, namely
109/4040 bushels per person-year. Consider what happens if the firm
doesn't revalue the price of iron on its books. Table 6 shows this
case. Since labor enters into each process, the rate of profits
has declined for all processes. The ratio of labor to the costs of
the other inputs is not invariant across processes. Thus, the
rate of profits has declined more in some processes than in
others. Notice especially, than the rate of profits is no longer
the same in the processes, A and D, that comprise the Beta
technique.
Table 6: Costs and the Rate of Profits at a Higher Wage
Process | Costs | Rate of Profits |
A | a1, 1(A) + a2, 1(A) p + a0, 1(A) w ≈ 0.5259 | 90.1 percent |
B | a1, 1(B) + a2, 1(B) p + a0, 1(B) w ≈ 0.6517 | 53.4 percent |
C | a1, 2(C) + a2, 2(C) p + a0, 2(C) w ≈ 0.05693 | -13.1 percent |
D | a1, 2(D) + a2, 2(D) p + a0, 2(D) w ≈ 0.04008 | 23.4 percent |
This accounting data does not reveal the firm's rate of return
in operating the Beta technique. The firm cannot be simultaneously
making both 23 percent and 90 percent in operating that technique. Furthermore,
this data provides a signal to the firm to withdraw from iron
production and make only corn. So this data says that something
must change.
4.3 Another Set of Prices with a Higher Wage
Perhaps all that is needed is to re-evaluate iron on the
firm's books. Higher wages have made iron more valuable. Table
7 shows costs and the rate of profits when iron is
evaluated at an accounting price of approximately 0.10569124 bushels per ton.
Table 7: Costs and the Rate of Profits with Iron Repriced
Process | Costs | Rate of Profits |
A | a1, 1(A) + a2, 1(A) p + a0, 1(A) w ≈ 0.6384 | 56.7 percent |
B | a1, 1(B) + a2, 1(B) p + a0, 1(B) w ≈ 0.6798 | 47.1 percent |
C | a1, 2(C) + a2, 2(C) p + a0, 2(C) w ≈ 0.06255 | 69.0 percent |
D | a1, 2(D) + a2, 2(D) p + a0, 2(D) w ≈ 0.06747 | 56.7 percent |
This revaluation of iron reveals that the firm makes a rate
of profits of 57 percent in operating the Beta technique. The firm makes
the same rate of profits in producing corn and in producing its
input of iron. But the manager of the iron-producing process would
soon notice that the cost of operating process C is cheaper.
4.4 A Final Set of Prices with a Higher Wage
So the firm would ultimately switch to using process C
to produce iron. The price of iron the firm would enter on its
books would fall somewhat, but still be higher than the original price at the low wage. Table 8 shows the accounting with a
price of iron of 10/101 Bushels per Ton. The firm has adopted
the cheapest process for producing iron, and the rate of profits
is the same in both corn-production and iron-production. The
accounting for this vertically-integrated firm is internally
consistent.
Table 8: Costs and the Rate of Profits at a High Wage
Process | Costs | Rate of Profits |
A | a1, 1(A) + a2, 1(A) p + a0, 1(A) w = 5/8 | 60 percent |
B | a1, 1(B) + a2, 1(B) p + a0, 1(B) w ≈ 0.6765 | 47.8 percent |
C | a1, 2(C) + a2, 2(C) p + a0, 2(C) w = 25/404 | 60 percent |
D | a1, 2(D) + a2, 2(D) p + a0, 2(D) w ≈ 0.06422 | 54.2 percent |
5.0 Conclusion
Table 9 summarizes these calculations. The ultimate result of
a higher wage is the adoption of a more labor-intensive technique.
If this firm continues to produce the same level of net output
and maximizes profits, its managers will want to employ more workers
at the higher of the two wages considered.
Table 9: A More Labor-Intensive
Technique at a Higher Wage
Wage | Technique | Labor-Intensity |
3/2780 ≈ 0.00108 bushels per person-year | Beta | 5 185/357 ≈ 5.52 person-years per bushel |
109/4040 ≈ 0.0270 bushels per person-year | Alpha | 5 45/49 ≈ 5.92 person-years per bushel |
Economists, such as Edwin Burmeister, have investigated what conditions on technology might be necessary to rule out the
illustrated effects. They know that no such conditions are known, and would be extremely restrictive anyways. A marginalist special case has not been specified for the
case in which more than one commodity is produced.
So much for the theory that wages and employment are determined
by the interaction of well-behaved supply and demand curves on the
labor market.
Appendix: Production Functions
The data above allow for the specification of two well-behaved
production functions, one for corn and the other for iron. For
illustration, I outline how to construct the production function
for corn.
Let L be the person-years of labor, Q1 be bushels corn, and Q2 be
tons labor allocated as inputs for corn-production during the
production period (a year).
Let X1 be the bushels corn produced
with Process A, and X2 be the bushels corn produced with Process B.
The production function for corn is the solution of an optimization
problem in which as much corn as possible is produced from the
given inputs.
Choose X1, X2
To maximize X = X1 + X2
subject to
a0, 1(A) X1 + a0, 1(B) X2 ≤ L
a1, 1(A) X1 + a1, 1(B) X2 ≤ Q1
a2, 1(A) X1 + a2, 1(B) X2 ≤ Q2
X1 ≥ 0, X2 ≥ 0,
Let f(L, Q1, Q2) be the solution of this Linear Program, that is,
the production
function for corn. (This production function is not Leontief.) The
production functions constructed in this manner exhibit properties
typically assumed in marginalist economics. In particular, they
exhibit Constant Returns to Scale, and the marginal product, for
each input, is a non-increasing step function. The production
functions are differentiable almost everywhere.
The point of this example, that sometimes a vertically integrated
firm will want to hire more labor per unit output at higher wages,
is compatible with the existence of many more processes for producing
each commodity. As more processes are used to construct the production
functions, the closer they come to smooth, continuously-differentiable
production functions. The point of this example seems to be compatible
with smooth production functions. It also does not depend on the
circular nature of production in the example, in which corn is used
to produce more corn.
References
- Pierangelo Garegnani. 1970. Heterogeneous capital, the production function and the theory of distribution. The Review of Economic Studies 37(3): 407-436.
- Arrigo Opocher and Ian Steedman. 2015. Full Industry Equilibrium: A Theory of the Industrial Long Run. Cambridge University Press.
- K. Sharpe. 1999. Notes and comment. On Sraffa's price system. Cambridge Journal of Economics 23(1): 93-1010.
- Paul A. Samuelson. 1966. A summing up. Quarterly Journal of Economics 80(4): 568-583.
- Ian Steedman. 1985. On input "demand curves". Cambridge Journal of Economics 9(2): 165-172.
- Robert L. Vienneau. 2005. On labour demand and equilibria of the firm, Manchester School 73(5): 612-619.