Risk is an inherent part of owner-occupation. Risk arises from the nature of housing as an asset whose value can fluctuate over time, the need for most households to maintain regular mortgage payments over a long period, and the uncertainty that arises from most payments fluctuating with interest rates. Since many of these risks are likely to be activated by trends in the wider economy, such as rising unemployment leading to income loss, or rising interest rates, they can affect many or even all owners with mortgages at the same time. Moreover, behaviour can become reinforcing, either through the normal operation of expectations in a (part) asset market, or because the collective distress of borrowers can force house prices – hence values – down for everyone. Thus risk at the individual level can translate into risk at the systemic level.