In his speech on the Chancellor's Autumn Statement last week to the House of Lords, Baron Skidelsky said that the average British worker is now £1,600 a year worse off than they were at the start of this parliament in 2010.
"The only relevant welfare measure - the measure by which the government should be judged - is GDP per head. GDP grew by 4.1%, between 2010 and 2013, but GDP per head has grown by only 2.3%, and the typical earner is £1,600 a year worse off," he said.
This, he argues, is because government policy has replaced unemployment by underemployment, meaning that skilled workers are stuck in low-paying jobs.
Underemployment is a situation in which someone is willing to work more hours than an employer is willing to offer them. It has been championed especially by academics David Bell and David Blanchflower as a key measure of remaining "slack" in the UK job market, or the amount of work that employers could employ people to do before having to offer higher wages.
The level of underemployment is generally seen to be significantly higher than the unemployment rate as the latter only counts people currently who are currently out of work. It's been cited by the Bank of England's Monetary Policy Committee on a number of occasions to explain why they have left interest rates at emergency levels despite recent improvements in the UK's economic growth prospects.
What it means is that despite lots of people being able to find work over the last four years much of these have been low-skilled, poorly-paid jobs. So while out-of-work benefits bill has been shrinking, the in-work benefits tab (used to provide support for low income workers) has been offsetting those falls.
This, Skidelsky says, is why the government has failed in its original aim to eliminate the budget deficit during this parliament.
"We would expect falling unemployment to increase tax revenues and reduce public spending. But not if unemployment is replaced by jobs which pay so little as to be exempt from tax, and which have to be propped up by benefits. For example, the number of housing benefit claimants who are in work has doubled since 2009."
With this warning in mind, it is no surprise that Chancellor George Osborne announced on Monday that "we are going to have to cut certain welfare bills like benefits that go to working-age people".