Seasonally Adjusted U.S. Household Medium Income (Marginal Revolution)
Also, see this comment to the Times article from user “Andrew” whom I strongly suspect is Marxist professor Andrew Kliman of Pace University in New York City:
A more interesting variable is the average rate of profit defined as the average profit / total capital input including the variable capital of labor and the fixed capital of machinery, R&D, factory, materials and energy, etc.
According to several earlier research results, the average rate of profit in the U.S. has indeed declined over a period of several decades. The decline has further accelerated the savings in variable capital investment, which then further decreases the average rate of profit. This vicious cycle between declined investment in the variable capital (hence increased investment in the fixed capital) and declined average rate of profit is non- stoppable in the capitalist system whose very existence depends on the maximization of private profits.
The conceivable future of the system is a situation of permanent and gross unemployment and ever-increasing profits resulting at the same time from the law of falling average rate of profit with no relieve in sight. The future share of wages/benefits of labor in the national income will shrink annually until all production process becomes 100% automated with absolutely no need for labor to participate. The hundreds of millions of able labor force will have nothing to do except going to streets throwing rocks against the police and military and, yes, making revolution.