16 Dar is the preferred destination, the nearest small town is more accessible, especially for first‐time migrants.

The first move is especially different, in that it is mostly about getting away from the village, not so much about maximizing one’s income. Having money to pay for the fare and a connection in the destination to help out are key. This is more likely the case for secondary towns than cities. But the migration process does not stop there. Yet, as time moves on and migrants settle in their occupations and advance in their life cycle, the window of opportunity for migration also closes, as family obligations grow and aspirations subside.

Ingelaere et al. (2018) conclude that this explains why many rural migrants end up in secondary towns; because they are much easier to access and navigate and because that is where they end up finding themselves further down their life cycle, when the migration window of opportunity starts closing.

# 6 Conclusion

The tidal wave of urbanization that is under way in developing countries, and particularly in Africa, needs policy responses. But we hope to have shown in this paper that viewing urbanization as an aggregate is empirically inaccurate. The composition of urbanization matters. In particular, the small town versus big city distinction should be made clearly and continuously. But it is not just a matter of empirical inaccuracy. The natural policy inclination is to equate urbanization with big city growth. Together with the natural metropolitan bias among national elites, this leads to disproportionate public investment in the capital city and other large urban agglomerations. But this neglects small towns, where increasingly much of the urbanization is taking place, and which contribute significantly to poverty reduction.

In this paper, we have reported on a line of research and policy analysis focused on Tanzania, which highlights the role of secondary towns in migration and poverty reduction. Using the national panel data as well as the KHDS panel, we first of all show that migration to secondary towns contributes more in aggregate to poverty reduction than migration to big cities, even though the typical move from a rural area to a town reduces poverty by less than the typical move from a rural area to a city. This is because there are many more rural‐to‐town moves. But how can this be, if the typical move to a city is so beneficial?

We answer this question by introducing “distance” and “migration” costs both in the physical sense (transport) but also in the sense of information, uncertainty and contacts in a broader setting. We adapt the standard Harris‐Todaro framework to incorporate these costs and show that in equilibrium we can indeed have more migration to small towns.

Empirical simulation with the KHDS data further shows how plausibly higher migration costs of moving to the city than to the town can solve the observed migration equilibria, given the observed wage rates across the different locations and sectors. We further show econometrically the importance of physical distance in explaining migration choice, it being understood that physical distance could stand as a proxy for all kinds of forms of social distance. Finally, qualitative analysis of the experience of