Unlike much of the existing research on the subject, this study adopts a theory-driven approach to investigating migrant poverty. This chapter thus aims to define the concept and explain why the methods chosen to measure it had to diverge from the ideal. It starts by evaluating the main approaches used previously to define and measure poverty and then presents the approach taken here. Following a critical evaluation of relevant theories from the wider international migration literature, it introduces the core components of the resource-based model adapted from the author’s earlier work (Eroğlu 2011, 2013) to examine the relationships between poverty and international migration. The chapter concludes by setting out research hypotheses for statistical testing.

Defining and measuring (migrant) poverty

Throughout its long history, the concept of poverty has come to be defined and measured in many different ways. There has been an extensive academic debate around the question of whether poverty should be understood in absolute or relative terms. The absolutists conceive of poverty as having an ‘irreducible’ core that is independent of context (Sen 1983: 159). Sen, for example, persuasively argues for maintaining the notion of ‘absolute need’ to be able to distinguish poverty from wider inequalities. This viewpoint is evident not only within the earlier subsistence (Booth 1891; Rowntree 1910) and basic needs approaches to poverty (ILO 1976; Streeton et al 1981), but also within the more contemporary works developed from the capability perspective (for example, Sen 1993, 1999; Alkire and Santos 2014; Anand et al 2020).

The relativists reject the absolute understanding of poverty by arguing that the requirements of life vary across time and space; therefore, people in need or poverty should be defined by looking at other people living in the same society at the same time. One of the most well-known representatives of this perspective is the relative deprivation approach pioneered by Townsend (1979), who conceptualises poverty as being deprived of the living standards widely approved and shared within a given society. Most prominent variants of this approach redefine the concept as ‘the enforced lack of socially perceived necessities’ (for example, Mack and Lansley 1985 Halleröd 1994; Gordon et al 2000).