You could just read Capital Vol 1 to know what I'm talking about, but here's a bit from, I think, the Soviet encyclopedia:
"The first industrial crisis (1825) and the first few armed uprisings of the proletariat during the 1830’s revealed the contradictory, transitory character of bourgeois relations. As a result, the tasks which bourgeois political economy had set itself were radically altered. “It was henceforth,” wrote K. Marx, “no longer a question whether this theorem or that was true, but whether it was useful to capital or harmful, expedient or inexpedient, politically dangerous or not. Pure, selfless research gave way to battles between hired scribblers, and genuine scientific research was replaced by the bad conscience and the evil intent of apologetic” (K. Marx and F. Engels, Soch., 2nd ed., vol. 23, p. 17).
"Vulgar political economy replaced classical bourgeois political economy, which within certain bounds had provided scientific analysis of capitalism but which by virtue of its class-based bourgeois narrow-mindedness was not able to overcome the vulgarizing element in its theories, an element which was later used by the vulgarizing theoreticians. The establishment of the dominance of vulgar political economy marked the beginning of the crisis in bourgeois political economy.
"The development of vulgar political economy is characterized by four basic stages: its origin in the form of a separate trend at the turn of the 19th century (T. R. Malthus and J. B. Say); its conquest of the dominant positions in bourgeois political economy and evolution during the period of free competition from the 1830’s to the 1870’s (J. Mill, N. W. Senior, F. Bastiat, W. Roscher, B. Hildebrand, and H. C. Carey); its continuation during the period of imperialism, from the 1870’s to the 1920’s (the subjective-psychological school including E. Boehm-Bawerk of Austria, A. Marshall of Great Britain, and J. B. Clark of the USA); the Newer (Younger) Historical School of K. Bücher and G. Schmoller of Germany; and the legal school represented by R. Stolzmann of Germany; and finally its development during the period of the general crisis of capitalism (J. Schumpeter, F. Hayek, L. Mises, W. Rostow, P. Samuelson, and others)."
encyclopedia2.thefreedictionary.com/Vulgar Political Economy
As for the worker's movements, I don't have a citation or anything, but the LTV was regularly used by them to argue for workers getting the "full value of their labor," prior to Marx's writing. He was deliberately trying to revive that kind of agitation and also enhance it with his own theory and more rigor.
Businesses don't obey mainstream econ theory at all. Shaikh talks at length about this, but Wolf (a much weaker theorist) also mentions this a lot. What they teach in business school is directly contradictory to what's taught in the econ departments! For example:
- businesses compete with each other by reducing their costs and then cutting prices to beat the competition. neo-classical theory says that the markets GIVE businesses their prices, and then they just optimize costs and output to make the most profit at the given price.
- businesses do not include PROFIT as a COST, as they understand that it is possible to make no profits and go out of business. On the other hand, the neo-classical model holds that a standard rate of profit (opportunity cost) is actually part of the costs!
- businesses do not have U-shaped cost curves. I honestly do not really know or care why the neo-classical cost curve model is U-shaped, but the important thing is that real cost curves are based on actual working conditions, shifts specifically. Costs per unit output are higher at the beginning of a shift (warmup), lower in the middle, lower near the end, and then approach infinity (theoretically) during the chaos of shift change or shutdown. The costs may also be higher depending on time of day and things like that.