The limitations of existing income-based measures do not necessarily suggest that traditional poverty measures should be replaced with measures of material hardship. Rather, proponents of material hardship measures see them as an important complement to income-based measures and providing a different picture of the extent to which families are able to meet certain basic needs. Although the prevalence of income-based measurement strategies in the US may imply otherwise, poverty and well-being are multifaceted phenomena, not unidimensional concepts (Beverly, 2001). The relationships between income, expenditures, consumption, and material hardship are complex and changes in income may not result in parallel changes in the distribution of material well-being or hardship (Mayer & Jencks, 1993). As a result, researchers have come to use multiple measures to examine various aspects of family well-being and need.
As a practical matter, different populations of people are identified as poor when different measures are used. In fact, research findings suggest that hardship measures and income measures do not necessarily identify the same populations. For example, Mayer and Jencks (1989) found that family income only explains about 14% of the variance in the number of material hardships experienced by Chicago families in the 1980s. Other researchers also have shown that the distributions of material hardship and income do not parallel each other (e.g., Jencks & Torrey, 1988; Mayer, 1997; Mayer & Jencks, 1993). Bauman (2002) found that although the level of income-poverty increased as families were less attached to the labor force, families that experienced the greatest amount of material hardship were those that worked part of the year and those who moved onto welfare during the previous year. Similar differences in the population groups identified by income and direct measures of material hardship have been found in international and developing country research (e.g., United Nations Human Development Report).
The fact that different measures identify different population groups reinforces the premise that while income-based and material hardship measures are closely related, they are somewhat conceptually different. Mayer and Jencks (1989) point out that this corresponds to what they view as two distinct goals of US government programs and policies: 1) to reduce poverty through income transfers and other employment-support programs; and, 2) to reduce specific forms of hardship through in-kind assistance. As noted by Rector et al. (1999), "the fact that household income falls below a specific level reveals little about the nature of material deprivation within the household" (p. 351).