This research was conducted in shops self-service of Pachuca and local commerce ofZacualtipán, were recorded prices of 24 products: rice, tortilla, tomato, lemon, jalapeno chile,milk, eggs, ham, sausage, beef, chicken meat, toilet paper, soap powder, toilet soap, toothpaste,beans, onions,...

This article shows that the criticism made by Hicks to the Treaty on the Currency of Keynes is not correct. Thus, we present the model of Keynes to show that the equality between investment and saving is a monetary equilibrium condition and not an identity. This result cannot be obtained in the...