Thus we can sometimes regard our ultimate independent variables as consisting of (i) the three fundamental psychological factors, namely, the psychological propensity to consume, the psychological attitude to liquidity and the psychological expectation of future yield from capital assets, the wage unit as determined by the bargains reached between employers and employed, and the quantity of money as determined by the action of the central bank; so that, if we take as given the factors specified above, these variables determine the national income (or dividend) and the quantity of employment.