Abstract: GDP growth is often measured poorly for countries and rarely measured at all for cities or subnational regions. We propose a readily available proxy: satellite data on lights at night. We develop a statistical framework that uses lights growth to augment existing income growth measures, under the assumption that measurement error in using observed light as an indicator of income is uncorrelated with measurement error in national income accounts. For countries with good national income accounts data, information on growth of lights is of marginal value in estimating the true growth rate of income, while for countries with the worst national income accounts, the optimal estimate of true income growth is a composite with roughly equal weights. Among poor-data countries, our new estimate of average annual growth differs by as much as 3 percentage points from official data. Lights data also allow for measurement of income growth in sub- and supranational regions. As an application, we examine growth in Sub Saharan African regions over the last 17 years. We find that real incomes in non-coastal areas have grown faster by 1/3 of an annual percentage point than coastal areas; non-malarial areas have grown faster than malarial ones by 1/3 to 2/3 annual percent points; and primate city regions have grown no faster than hinterland areas. Such applications point toward a research program in which “empirical growth” need no longer be synonymous with “national income accounts.”

Abstract: Social scientists have previously understood the night through a frontier metaphor. This has pitched night as an empty or lightly inhabited space into which the urban, capitalist day has been expanding. The contemporary increase in nocturnal research has complicated this picture, showing an increasing multiplicity of complexly lived, structured and experienced nights across the globe. This paper looks to retrieve the concept of night as frontier by drawing on postcolonial theories to generate a more subtle conceptualisation of ‘frontier’, while also arguing that recent research reveals that this frontier is now fragmenting. By exploring research into a series of core themes – artificial light at night and darkness; night-lives; and global nights – I then explore what such an understanding of night allows us to say about current research. As nocturnal social science continues to mature, a more critical eye will need to be paid to the complexity of shifting power relations and identities within this fragmenting nocturnal frontier.