Second, the proposal is for a benefit to be paid on the basis not of citizenship but of "participation", and for this reason it is referred to as a "participation income" (PI). "Participation" would be defined broadly as making a social contribution, which for those of working age could be fulfilled by full- or part-time waged employment or self-employment, by education, training, or an active job search, by home care for infant children or frail elderly people, or by regular voluntary work in a recognised association. There would be provisions for those unable to participate on the grounds of illness or disability. The notion of contribution would be broadened, taking account of the range of activities in which a person is engaged. Reflecting the features of the twenty-first-centry labour market described in Chapter 5, the definition of participation would allow for people holding a portfolio of activities over, say, a thirty-five hour week, and people may qualify for fractions of this period.