Peter Mathias in an attemptto find out how and why numbers rose he points out that after mid 18thcentury fertility had twice the effect of falling mortality. The average age ofpeople marrying for the first time fell, as did the numbers of people nevermarrying, which meant more opportunity for babies, and more babies. Britishpeople had previously had a relatively late age of marriage compared to thecontinent, and a large number of people never did at all. Nuptuality, overallhealth improvements and a better diet from improved food production and higherwages resulted in better health of mothers and the curtailment of deaths ofwomen in the reproductive age groups induced higher birth rates. Economical andsocial conditions influenced marriage patterns. The expansion of employment inmanufacturing and trading regions offered higher wages, allowing people tocomfortably start families, and as they moved to the industrial centres, theywere likely to meet more, and that increased the chances of matches, andsettling downOverthe last 60 years the world experienced the most intensive expansion in urbanpopulations in many Less Developed Countries.
People across rural regions ofAsia and Latin America flocked to cities where they transformed the ecology andculture of modest-sized cities, establishing bustling and sprawling urbancentres that later became beacons for rural migrants. * Over the last decadesimproved health care services, mass-immunization programs, access to cheapmedicines, and diffusion of basic knowledge about personal hygiene and sexuallytransmitted diseases led to sharp reduction in mortality. Those interventionsreduced infectious and parasitic diseases that used to thrive in denselypopulated urban settlements in the past and determined to a large amount urbanpopulation growth.
*The understanding of thelevel of urbanization or its scale in developing countries is challenged bydifferences in the definition of urban and in turn, the lack of reliable data.Furthermore, the process of urbanization is far from homogenous across regionsand swathes of territory that are wholly different in terms of economy andpolitical structures. Regarding Britain in 19th century, where less mortalitywas once the favoured explanation for population growth, it is generally heldto be the increase in marriage and birth rate which caused the explosion.
Incontrast and in my personal belief, although high birth rates make the naturalincrease of the population an important source of city growth in developingcountries, the movement of people from rural to urban areas within the country(internal migration) is the most significant factor contributed to urban growth