In a City bar back in 1998, an academic was discussing modern banking with his City colleagues from university. He was encouraged to invest in shares as their growth was well above inflation. He pointed out, however, that the inflation index does not take into account the growth of share price and as a consequence the market will run out of cash to pay for shares at some point. The only way would be down—a shares price crash.
fascinating… House of Commons - Treasury - Written Evidence