text: ments were also focusing on the development of rural zones (e.g. Rwanda, Senegal, Seychelles and Sierra Leone). l-ladagascar follows a somewhat different policy, by directing migrants to underpopu­ lated zones. Egypt, Kenya, Nigeria and the United Republic of Tanzania have elaborate spatial distribution strat.egies, involv­ ing rural development, "growth poles", the creation of networks of intermediate urban centres, etc.: these strategies usually in­ valve a comb in at ion of limited decentralization at the national and regional level and selective concentration at the local level. 21. On the whole, although it has been argued that the op­ timal spatial distribution of population is that which con­tributes most directly to the achievement of specific explicit or implicit development goals, empirical observation appears to of­ fer no general guidelines as to how particular population dis­ tribution patterns may favour or inhibit development. Given the difficulty of specifying \.'hat is the optimal spatial distribution of a population, policies on population redistribution in African countries have tended to concentrate on establishing goals in terms of the direction of desired change, including slowing down the growth of the primate city, expanding inter~ediate cities and slowing down rural population growth. Colonization and resettle­ ment schemes have produced more failures than successes, and recently greater prominence has been given to measures that af­ fect the spontaneous redistribution of population. 22. Broadly, the policies which have been adopted to stem the problems of population d istr ibut ion in ECA ·member States fall into three categories: those affecting international migration: those designed to induce internal redistribution: and those designed to effect spontaneous redistribution. 23. One of the post-independence develorments which has prompted international population movements in the African region is the pursuit of policies aimed at removing cuEtoms barriers and allowing the free movement of people and goods. Government 
analysis: The text appears to be discussing population distribution and migration policies in African countries, with a focus on urbanization, rural development, and regional planning. It seems to be more concerned with the social and economic implications of population growth and migration, rather than environmental or natural resource issues.