The 'double precarity' of employment insecurity and unaffordable housing and its impact on mental health.

This paper describes who is most likely to experience household employment insecurity and housing affordability stress - double precarity - and estimates the degree to which housing affordability mediates the effect of employment insecurity on mental health. We use a cohort of 24,201 participants in 2016 Household, Income and Labour Dynamics in Australia survey (6.2 repeated measures on average). We estimate the likelihood of onset of household employment insecurity, housing affordability stress and change in housing costs using longitudinal regression analyses for socio-demographic groups. We assess mediation by estimating how much exposure variable coefficients attenuate with inclusion of a mediator in fixed effects regression models. We also apply causal mediation methods to fixed-effects regression models to better account for exposure-mediator interaction and meet strict model assumptions. If people's households become insecurely employed, there are five times greater odds of them also experiencing housing affordability stress (OR 4.99 95%CI 4.21-5.90). Key cohorts within the population are shown to be especially vulnerable to double precarity - notably single parents (OR 2.91, 95%CI 1.94-4.35) and people who live alone (OR 4.42, 95% CI 3.03-6.45) (compared to couples), and people who are recently separated or divorced (OR 2.59, 95%CI 1.81-3.70). Mediation analysis confirms that household employment insecurity has a small, negative effect on mental health (Beta -0.24, 95%CI -0.38-0.11 on a 1 to 100-point scale with 10-point standard deviation). Estimates from casual mediation analyses suggest housing affordability accounts for 20% of the total effect; likely concentrated in the lowest and highest strata of income. Employment and housing insecurity represent a form of double precarity for people in households with a single income. When we consider the impact on mental health, we find evidence of a causal relationship between insecure employment onset and mental health, around one fifth of which is mediated by changing housing cost and onset of affordability stress.