“…Previous evidence of IWTC improving smoking19 (also in Whites/Hispanics)18 in the USA and life satisfaction in the UK,14 compared with the null-findings for SRH in NZ, if not due to improvements in the former health outcomes not translating into improved SRH,14 could be explained by differences in IWTC designs, such as NZ's IWTC universally covering low-income and middle-income groups, whereas those in the USA and the UK exclusively target low-income families. Furthermore, if the broad welfare state provision of public health and social services fulfil the basic health needs for low-income and middle-income families in NZ, but these needs are not equally met by the lower safety nets provided to low-income families in the USA/UK, then additional income from IWTC should impact health less in NZ than in the USA/UK.…”