In Defence of Liberty

Driven by data; ridden with liberty.

A Recurring Error


Some corrections have to be issued again, and again. (Edited: Wikimedia Commons)

Dr Eoin Clarke’s new venture, Labour Rebuttal, claims to be ‘fact-checking Tory fibs, all the way to polling day’. This blog has laid dormant since November 12th 2015.

Back in October 2015, we can observe some recurring errors from Dr Clarke [1].

In response to the Chancellor’s announcement on labour market data from the Office of National Statistics (ONS), Dr Clarke wrote:

First let us test Osborne’s claim that UK employment is the highest in our history. The current UK employment rate is 59.9% which is not the highest employment rate ever, in fact it has been over 60% many times since the 1970s [see here]. Perhaps what George Osborne was referring to was the employment rate of those aged 16-64, which currently stands at 73.6%. That figure is indeed the highest since records began in 1971, but that comes with caveats. First, those who participate in government work schemes are now included in the data. Also, the figure of 73.6% is more or less than within 1% of what the employment rate for those aged 16-64 was at many times during the 2000s the 1990s and the 1970s.

This is matter of how the employment rate is defined. The ONS defines [2]:

The proportion of people aged from 16 to 64 in work is known as the employment rate.

This is a worrying equivocation by Dr Clarke. It was not some unusual preference of the Chancellor to highlight this measure of “rate of employment”, as Dr Clarke insinuates, but the recommended practice of the statistical bureau which the Chancellor is quoting, and of which Dr Clarke should have been aware.


The employment rate has reached a new pinnacle. (Source: ONS)

“Zero Hours Jobs”

Dr Clarke continues with another previous error [3]:

The question also needs to be asked what type of jobs are being created in Tory Britain, and the simple truth is that many of those new jobs are insecure. For example, according to the ONS, the number of workers in Zero Hours Jobs has risen by 345% since 2010. Although there are now more than 1.5 million zero hours contracts in usage, the more accurate figure for people who say that their main job is a zero hours contract is a smaller figure of 744,000 which is up from 167,000 in 2010.

After linking to some data, Dr Clarke persists:

The ONS remind us that this data is people who are self reporting their employment on a Zero Hour Contact and that some of the rise might be explained by increasing awareness of what a Zero Hour Contract is. That ONS advice was in 2013, however, and the figure has shown no sign of leveling off since then. Given that the term is now one of common usage, and that the figure continues to rise, we can be more confident than ever that the rise in the number of workers employed on these insecure contracts has indeed risen.

Dr Clarke then includes a graph:


The spike is the problem here. (Source: Labour Rebuttal)

The problem is that Dr Clarke’s prose includes the reason as to why his graph should not be trusted. The ONS undertook an employer-based survey on contracts with no guaranteed minimum working hours because the term ‘zero hours contracts’ was esoteric and unfamiliar to most employees. This meant there could be a serious underestimate in their usage in the employee labour market. This severe underestimate would affect most of the time in his graph.

Caveats and neglect

Dr Clarke then ignores all these concerns, and neglectfully asserts:

Unemployment, say the ONS, has fallen by c0.7m since May 2010. This is a considerable drop and brings unemployment closer to the levels it was before the global recession. What is a genuine worry to many, however, is that during this same period the number of Zero Hours workers has risen by c0.6m. Thus, a fear exists that much of the reduction in unemployment can be explained by an increase in insecure employment. Osborne’s boasts ring hollow.

This is the actual comment by senior ONS statistician Nick Palmer on the increase in zero-hours contracts, published in September 2016 [4]:

Both measures suggest there may have been a small trend towards more use of zero-hours contracts, although the usual margins of error associated with the surveys’ estimates mean that we cannot be certain of this. Moreover, as previously, the results from the Labour Force Survey might have been influenced by increased recognition of the term ‘zero hours contract’ among respondents.

Despite the claim that “we can be more confident than ever” in the rise of zero-hours contracts, this still falls short of high levels of statistical confidence. Moreover, the report states that two-thirds of the increase is from people in their job for more than a year, so “the overall increase does not necessarily relate to new zero hours contracts”. Furthermore, we cannot be certain, or even believe it likely, that the count of zero-hours contracts has risen by 600,000 in the last five years.

When reading the output from a statistical organisation such as the ONS, it is important to note the key definitions and caveats.


[1] Clarke, E., 2015. Why George Osborne’s boasts about job creation ring hollow… Labour Rebuttal. Available from: [Accessed: 17th January 2016]

[2] ONS, 2015. UK Labour Market, December 2015. Available from: [Accessed: 17th January 2016]

[3] Masters, A., 2014. Statistics and Lampposts X: Zero Hours Contracts and Caveats. In Defence of Liberty. Available from: [Accessed: 17th January 2016]

[4] ONS, 2015. Zero-hours contract in main job now reported by 744,000 hours. Available from: [Accessed: 17th January 2016]



This entry was posted on January 22, 2016 by in National Politics and tagged , , .
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