(a) Optimum population is the size of population which when combined with the available resources and level of technology will yield the highest output per head.
(b)(i) There is likely to be a high level of unemployment.
(ii) There will be a high dependency ratio.
(iii) There will be pressure on resources as government expenditure on provision of social amenities will be on the increase.
(iv) Per capita income will fall which may result in a low standard of living.
(v) There will be congestion on land which will affect productivity in agriculture.
(vi) There will be urban congestion with its attendant social vices.
(vii) There will be low savings and capital formation.
(viii) There may be balance of payment problems due to an increase in import bills to meet the shortfall in local production.
(c)(i) Family planning.
(ii) Education on the need of smaller family sizes.
(iii) Implementation of tighter immigration measures.
(iv) Discouraging early marriages.
(v) Encouraging girl's education.
(vi) Discouraging polygamy.
(vii) Strengthening social security systems for the aged to forestall all the needs for large families.
(ix) Enactment and enforcement of laws to regulate family size.
(x) Making cost of child-raising high by abolishing free education.