... way of thinking.7 .1. 5. The multiplier and the accelerator The fourth great stream of thought in dynamic theory in the inter-war periodwas the study of the interaction between the multiplier and ... years of high theory: iafter the 19 29 crash. American loans dried up, while the Bank of Francedecided to convert its sterling reserves into gold. Then, in 19 31, a wave of panic, caused by the ... circulation, P the level of prices, and T the level of transactions, becomes an explanation of the value of money once V, T, and M have been fixed exogenously. The dif-ficulties and the interesting...