In the current state of the art literature, inequality research has primarily focused on the Global North (e.g. Kuznets 1955; Lindert 1986; Milanovic et al. 2011; Piketty 2014), while the studies of the experiences of the Global South are more scattered (Berry 1990; Bigsten 1986; van Zanden 2003). There are several explanations for the omission of the African region from current research, one of them being the difficulty of securing good quality data. The gap is, however, not only an empirical one. Because much of the theoretical thinking around mechanisms driving long-term inequality trends is based on an understanding of history, the omission of the Global South also leaves a theoretical gap.
The necessary information to answer why incomes are so unequally distributed in African countries, and when inequality started rising, is scattered, unreliable, or all together missing. We know, for example, very little of inequality trends during the colonial era and therefore we cannot explain what caused inequality levels in Africa to be among the highest in the world at the time of independence in the 1960s (UNU-WIDER 2019). Subsequently, some scholars suggest that during the independence period inequality in Africa peaked in the 1980s after which it started to decline, but that there are also large unexplained discrepancies between countries (Sala-i-Martin and Pinkovskiy 2010). However, we are again unsure about the long-term trajectories and the mechanisms, and we are poor at explaining the role of pre-colonial and colonial legacies. At the moment, there is simply not enough empirical knowledge about longitudinal inequality trends to be able to theorize about their drivers and determinants. Therefore, our project starts at the very beginning with compiling information by collecting data and constructing indices. Only then do we move on to test, evaluate and develop existing theoretical models making them relevant for Africa.
Our primary methodological approach is the construction of social tables (Milanovic et al. 2011). Based on the quantitative and qualitative material collected and applying a mixed methods approach, we divide populations into various income groups also known as social classes. Differently from other approaches focusing on capturing the incomes of top income earners (e.g. Piketty), we study the whole population. We are capturing between group inequality, but considering the data restrictions that we have we cannot follow individuals. It is necessary for us to calculate the share of the population represented by each social class and therefore the number of population censuses restricts the number of social tables. Nevertheless, with the construction of social tables over consecutive years, we can follow changes between social classes over time and thereby determine long-term inequality trends.