Most of the world's developing nations are primarily rural and agricultural. Therefore, governments have tended to place a policy emphasis on development in those sectors, usually as a result of employing the relatively straightforward argument that they should focus on the needs of the largest proportion of the inhabitants. The movement of population is generally seen in the light of rural–urban migration, although there is some evidence and opinion that this is not per se as massive as usually estimated. In addition, Rakesh Mohan has developed an economic model that suggests a close linkage between the success of rural development policies and an expansion in urbanisation, based on the assumption that the former increase both demand for and awareness of urban goods and services, resulting in a greater propensity for people to move to those places where these resources are most readily availabe. Thus, the more it has to turn its attention to the urban consequences.