Rural-urban migration of labor continued in developing countries although there was a high and increasing level of unemployment and underemployment in urban areas in 1960s & 1970s. The expected income model of migration was designed in HT model in the presence of labor market imperfections and an assessment of the probability to get an urban job.
The HT model argues that rural-urban migration is stimulated primarily by individual rational economic calculations of relative benefits and costs. Todaro7 (1969) proposes that individual migration decisions are based on the difference between the discounted expected income in urban and rural areas net of migration cost. In other words, individuals migrate if V(O) =∑_(i=0)^n [p(t) Yu(t) – YR(t)] e^(-it) dt - C(O) is positive, V(O)= discounted present value of the net expected urban-rural income stream over the migrant’s time horizon; Yu(t) and YR(t) are the average real income of individuals employed in the urban and the rural economy at a given point of time, respectively; n is the number of time periods in the migrant’s planning horizon; i is the discount rate reflecting the migrant’s degree of time preference; C(O) is cost of migration, and p(t) is the probability that a migrant will have a secured urban job in period t (Todaro, 1969:142 and Todaro 1980:368). The main contribution …show more content…
Wu*( (λAu )/(Eu+Uu)) >Wr (2.4)
The rural-urban equilibrium expected wage condition is then, E(Wu) = Wr; which becomes Wu*( λEu/(Eu+Uu) ) = Wr (2.5)
The probability of urban employment plus urban unemployment is one.
Thus, the Harris-Todaro model equilibrium for urban unemployment rate is given by: 1 - ((λEu )/(Eu+Uu)) (2.6) OR it is given by 1- (Wr/Wr) Since Wu *((λEu )/(Eu+Uu)) = Wr as in (2.5) (2.7)
The Todaro paradox occurs when the increase in labor supply is greater than the increase in labor demand. In conditions where the elasticity of urban labor supply with respect to the income differential between urban and rural areas is greater, an increase in job creation will generate an increase in the number of unemployed workers. This is because migrants will be more attracted and induced to migrate to the urban centers as a result of job creation in urban destination (Todaro, 1980).
2.2.1. Migration and urbanization
Population distribution and re-distribution through migration are among main features of the population dynamics in Ethiopia. The following describes the major characteristics, trends and differentials of internal migration, urbanization and population distribution in Ethiopia (Bhatia,