Marx’s law of the tendency of the rate of profit to fall (LTRPF) has either been heavily criticised or ignored as being an irrelevant explanation of crises under capitalism, both theoretically and empirically. The critics are not from mainstream economics, who generally ignore the role of profit in crises altogether. They partly come from post-Keynesian economists who look to ‘aggregate demand’ as the driver of capitalist economies, not profit. But the biggest sceptics come from Marxian economists.