Economic Growth and Income Distribution
|January 12, 2014||Posted by Fred Foldvary under Editorials|
One of the topics that has not received enough attention in economics is the effect of economic growth on the distribution of income. So if you want to understand it, you should get a piece of paper. I’ll wait until you have it …
Now on the lower left side, draw a rectangle with a height longer than the width. The top half of the paper should still be blank. We will use an agricultural model with one product, corn. At first, the only factors are land and labor. Now draw small circles of equal size in the rectangle. These are farms of equal size. The yield is ten bushels of corn per farm per period of production. As long as there is free land available, land rent is zero, and the entire yield of ten goes to wages.
Now draw another rectangle to the right of the first one, three-fifths as high. Label this “six,” because the output in that land is six bushels of corn. All the farm workers are equally skilled and work the same number of hours, so the lower yield is due to its being less productive land. With rent at zero because there is free land, the wage is six. The wage in the ten-bushel land has now fallen to six, because workers are mobile and equally skilled. The extra four bushels in the ten-bushel farms are now land rent.
For rent and wages, it does not matter whether the owner is also the worker, or whether he hires labor at six bushels, or whether he rents out the land to a tenant at four bushels. The economic rent is the difference in the productivity of the two lands, regardless of who are the owners, tenants, and workers. If the landlord happens to charge only three bushels from a tenant, the economic rent is still four: three go to the landlord, while one bushel is the yield as rent kept by the tenant.
In classical economics, the least productive land in use is called the “margin of production.” There is a “law of wages,” which states that the wage level for the economy is the wage at the margin of production. There is a “law of rent” which states that the rent of a plot of land is its output minus the normal costs of labor and capital goods, such as, in our simple model, the difference between the output of the lands yielding ten and six.
Now add a third rectangle to the right of the six-bushel land, and label this “four,” because this is the new margin of production yielding four bushels. Wages there are four, making the wage also four at the lands yielding ten and six. Now rent in the ten-bushel land has risen from four to six, and rent at the six-bushel land has risen from zero to two. You can see that as the margin of production moves to less productive land, wages fall and rent rises.
Now let us introduce a plow, which represents both more capital goods and better technology. The plow costs two bushels and completely depreciates each period, requiring a new plow for the next period. The plow doubles production at each plot of land. So on the rightmost rectangle, draw another rectangle just above the first one, attached to it, with an equal size, representing the doubling of output.
Is it worth buying the plow? Yes! The farms at the margin, having yielded four, now yield eight. After paying for the capital good, the plow, the output is six, which all goes to wages. Wages there have risen by 50 percent. By the law of wages, wages in the other farms have risen to six.
With the plow, the farms that yielded six now yield twelve. Draw a rectangle above the middle one, with equal size. Now the distribution of the twelve-bushel output is two to capital goods, six to wages, and the remainder, four bushels, to rent. Rent there doubled from two to four bushels.
Now do the same for what was the ten-bushel land, which now yields twenty. The distribution is two to capital goods, six to wages, and the remainder, twelve bushels, to rent. Rent there also doubled, from six to twelve bushels. (A similar graph of the factors).
Now we can see the effect of the economic growth caused by more and better capital goods. Wages have risen by fifty percent, while rent doubled. We can calculate this in bushels. Suppose there were ten farms in each grade of land. Write this down: before the plow, for the three lands, output was 100 + 60 + 40 = 200. Wages were 40 times 3 = 120. Rent was 60 + 20 = 80. So wages were 60 percent and rent was 40 percent of income.
With the plow, output doubles to 200 + 120 + 80 = 400. Are you writing this down? Wages are now 60 times 3 = 180. Capital yields are 2 bushels per plow times 30 farms = 60 bushels. Land rent is 120 + 40 = 160. Wages are now 180/400 = 45 percent of income. Capital yields = 60/400 = 15 percent of income. Rent = 40 percent of income. Wages rose by 60 bushels, while rent has risen by 80 bushels.
The portion of income going to wages has fallen from 60 to 45 percent, but the portion of rent stayed the same, 40 percent. The doubling of output doubled the rent, but because the plow has a cost, wages could not double, but they did rise by 50 percent. Labor benefits from the greater productivity, but landowners benefit more. If new technology and capital goods were to similarly double production again, the distribution of income would keep the same proportions.
If the ownership of the land value is concentrated, then much of the gains from economic expansion is distributed to a few landowners. The greater rent going to a few owners explains much of the inequality of income today throughout the world. These landowners do nothing to generate the growth. Usually, better capital goods also requires better human capital, greater skills. So the economic growth and development is caused by entrepreneurship and investment in capital goods and human capital, and the yields properly go to a return on the capital goods, the capital yield, and to greater wages, including the gains to the entrepreneurs. But the greater rent is a surplus windfall to the owners of land that obtain the rent just by holding title.
If we believe in human equality, the land rent should be distributed to all the people equally. Then all the people would equally benefit from the greater productivity. The effect of greater productivity on the input-factor distribution of income has been neglected, so this model should be taught in all courses on the principles of economics.