Causes of urbanisation and counter-urbanisation in Zambia: Natural population increase or migration?

Abstract: http://journals.sagepub.com/doi/full/10.1177/0042098018787964#abstract

Scholars have debated the causes of urbanisation and counter-urbanisation in Zambia. Some argue that the most important cause is the natural rate of growth of the urban population. Others argue that the most important cause is population migration to and from urban areas. This study contributes to this debate by using, for the first time, statistical evidence from the Zambian Population Census microdata files. These data allowed us to apply the intercensal forward survival ratio method to measure (i) net migration between urban and rural areas and (ii) the natural population growth in both urban and rural areas over the periods 1990 to 2000 and from 2000 to 2010.

The results showed that the most important cause of urbanisation and counter-urbanisation was net migration rather than natural urban population growth or decline. Although natural urban population growth was roughly twice that of net migration, this had very little influence on urbanisation because it was matched by the natural growth of the rural population. Specifically, between 1990 and 2000 Zambia experienced counter-urbanisation, even though the urban population increased substantially in absolute terms. The main reason for this counter-urbanisation was some migration from urban to rural areas. This might seem counter-intuitive but this is true because the level of urbanisation is calculated as the proportion of the population living in urban areas. Therefore, since the natural growth of the rural population more or less matched the growth of the urban population, it had little effect on the urban proportion of the population. The relatively small numbers of migrants who left urban areas was therefore enough to result in counter-urbanisation. Between 2000 and 2010, Zambia experienced a rise in urbanisation. Again, the natural growth of both rural and urban populations was much more than net migration, with the result that it was the number of migrants to urban areas that tipped the balance between the urban and rural proportions of the population. We therefore conclude that, in the case of Zambia over the period 1990 to 2010, our results show that migration contributed more to urbanisation and counter-urbanisation than did the natural growth of the urban population.

We also addressed the theory that urban economic growth can cause urbanisation through migration from rural to urban areas, and that urban economic decline can result in urban to rural migration. Our results indicate that economic decline during the 1990s resulted in decreased urban employment and a dramatic rise in urban unemployment, which in turn caused migration from urban to rural areas. Conversely, during the 2000s, absolute employment grew and unemployment decreased, which corresponded with increased rural-urban migration (resulting in net urbanisation). Our findings also show that even during the period of net out-migration from urban areas and high urban unemployment levels, the resident urban-born workforce continued to grow strongly through natural increase. Thus, these results also show that urban population growth can increase substantially in the absence of urban economic growth, thereby increasing urban unemployment and urban-rural migration.

We therefore conclude that both migration and natural population growth can make a contribution to urbanisation and counter-urbanisation: There is no necessity for either one of these processes to be the dominant cause of urbanisation or counter-urbanisation. The reason for this is that these two different processes are caused by different mechanisms that operate under different conditions. Under conditions of urban employment growth, migration from rural to urban areas may be the larger contributor to urbanisation. However, higher mortality rates in urban areas compared to rural areas could counteract this tendency and thereby result in counter-urbanisation. Correspondingly, if mortality rates are lower in urban areas than in rural areas, and fertility rates are higher in urban areas than in rural areas, then urbanisation could take place without any migration from rural to urban areas.

Read the paper on Urban Studies - Online First here