A more realistic approach to the theory of optimum population has been presented by Mukerjee (1941), Professor of Economics and Sociology in Lucknow University , Mukerjee gave the concept of the integral optimum. In Political Economy of Population he writes: “The true optimum of population is the integral optimum which is based on a harmonious co-ordination of the optima in the successive levels of ecology, economy and state in respect of (a) the expectation of life, (b) real income, and (c) personal happiness and self-expression, all these from the individual stand-point, and of (a) the stability of the economic base and occupational balance, (b) the regularity and continuity of employment, and (c) national security and power, all of the latter from the collective standpoint.” Mukerjee said that this optima was, however, only a hypothesis (though of a great analytical value) and cannot be quantitatively measured or expressed.