with at least one member being a union member (31.5 percent versus 17.1 percent, respectively) is higher among the in-work non-poor compared with the in-work poor households. Table 11. Additional labour market characteristics and in-work poverty rate Mean weekly hours Main earner works full-time (≥ 30 per week) Underemployment Permanent contract Union membership In-work non-poor 39.3 (9.4) 92.8% 6.4% 97.2% 31.5% In-work poor 29.7 (13.8) 58.6% 14.4% 84.6% 17.1% Source: HLFS 2017 September quarter. Notes: Std dev in parenthesis. Sample size of 7,836 working households. 4.8 Income sources Here we look at the main income sources for working households (poor and non-poor) and present these disaggregated by household structure. Figure 9 shows the mean proportion of total household income that stems from wages and salaries; benefits; pensions (superannuation); WfF and AS; and other sources (which encompass withholding payments, student allowance, paid parental leave and ACC claims). We find that independent of household structure, on average 90 percent of household income is generated by wages and salaries for households that are in-work non-poor (the two exceptions are single-parent households (at 80 percent), and two or more family households (at 78 percent)). This share declines substantially for in-work poor households: for example, 48 percent of household income for in-work poor single-parent households comes from wages and salaries compared to an average of 80 percent for their non-poor equivalents (a difference of 32 percentage points). The difference in income sources between in-work poor households and in-work non-poor households has also been explored using UK data by Hick and Lanau (2018b). Noticeably, Figure 9 shows that the prominence of alternative sources of income for in-work poor households is heterogeneous across different household structures. Benefit receipt plays a greater role for single-parent households, for two or more family households and for one-person households, relative to couples with or without child(ren). Pensions play an important role in couple without children households. Furthermore, we find that income from WfF and AS are especially relevant for couple with child(ren), single-parent and two or more family households: in all three cases, the share exceeds 10 percent. Page 36