First, measuring income is complicated and involves arbitrary cut-off rules. Taking and 'wealth' into account encourages dis-saving, which reduces resilience at times of financial stress.

Second, applying means tests entails high costs, both for the administration and for claimants who must travel to benefit offices, wait, queue, fill in lengthy forms, produce supporting documents and so on, all of which take time and often hard cash.

Third, means testing involves intrusive questions, including about claimants' intimate personal relationships, that may be followed up by home visits, for example, to check that there is no live-in partner earning an income. It is a regime of prying, invasion of privacy, and presumption of guilt rather than innocence, which demeans the staff running it as well as claimants.

Fourth, as a result, the process and the prospect of it are stigmatizing. This is often deliberate, to reduce the cost of welfare by deterring claimants. [...]

This leads to the fifth failing, low-take-up. [...]

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Sixth, means testing undermines social solidarity, separating 'us' from 'them'. We, who support ourselves, pay taxes to support them, the scroungers. [...]

The seventh and most well-known failing is the notorious poverty trap [...] people on benefits who take a minimum wage job would lose money [...]

This leads to the eighth failing, the inevitable drift to workfare [...] the state is left with little choice but to force people to take low-paid labour.

A ninth failure is that means-tested social assistance deters stable household formation. [...]

A tenth failing relates to income-tested Jobseeker's Allowance, which is determined on the basis of family income. If one of a couple is unemployed, the couple loses financially if the other is doing a small amount of paid labour. [...]