Despite the theoretical distinctions, the practical implications of using one or the other dominate. Income is easier to measure when there are few sources of income and when income from those sources is recorded for administrative purposes, such as taxation or payroll contributions. Income information is also cheaper to collect in those settings, allowing for larger sample sizes and more precise measurement. For example, Atkinson, Cantillon, Marlier and Nolan (2002) interpret the US moving from different poverty lines for men and women to a common poverty line as a move from a standard of living to a rights approach. Whether income or expenditure data are used, if there are economies of scale in consumption, individuals in larger households will have their needs better met by the same level of income or consumption than individuals in smaller households. For this reason, equivalence scales are used, which count the number of "adult equivalents" (often male) in a household.