One of the most frequently cited statistics summarising the process of urbanisation which is currently being experienced in the so-called developing world is that the towns and cities of these poorer countries are receiving a staggering 45 million new urban inhabitants each and every year. This vast number of new ciry dwellers in the poorer countries of the world - amounting to somewhere in the region of 125,000 new urban citizens a day worldwide - is the outcome of high levels of rural-to-urban migration in combination with high rates of natural increase of the population. By comparison, approximately 7 million urban residents are added on an annual basis to the towns and cities in the countries of the more developed world.