How big is the gap between the number of rape cases and convictions?

The rape and murder of a young student in India a few weeks ago has focused the global media spotlight on violence against women, and today's Independent highlights the problem here in the UK.

The infographic on the paper's front page and the accompanying editorial claim that there may be as many as 95,000 rape victims every year. Last year only 15,670 rapes were reported to the police, 2,910 cases were heard in court and a mere 1,070 cases resulted in a conviction.

To keen social media users, the graphic might look familiar as it bears a striking resemblance to one used by the Washington Post earlier this week, which was widely distributed by Facebook and Twitter users.

However as Slate subsequently pointed out, there are a number of problems associated with the figures behind the Washington Post's example. So has the Independent fared any better?

Analysis

Perhaps the biggest problem with the Washington Post's graphic - which was in fact put together by the US campaign The Enliven Project - is that it assumes that there's one rapist for every rape committed.

To illustrate why this is a problem, Slate pointed out that while US figures suggest that as many as one in five women have been subjected to a rape (similar figures for this side of the Atlantic were also released today), this doesn't mean that one in five men is a rapist. In fact, a large number of these attacks would have been carried out by serial offenders, so to describe the number of convictions in terms of the number of 'rapists' (as the Washington Post did) is misleading.

Mercifully, the Independent has avoided this mistake and clearly identifies the 95,000 as the victims of rape, not the number of offenders. But where does this figure come from, and is it accurate?

The number has been taken from a Ministry of Justice (MoJ) analysis of victims of sexual assault, published yesterday. The 95,000 figure did indeed feature as an upper-estimate of the number of 16-69 year olds (both male and female) that had been the victim of a rape in the previous year, although there is a rather sizeable caveat.

As the table below shows, the 95,000 figure refers to the upper-bound for the estimated number of rapes and attempted rapes. If attempted rape is excluded, the estimated range for the number of rapes is between 43,000 and 73,000, the vast majority against women. Of course, attempted rape is still treated as one of the most serious sexual crimes by the MoJ, but the nuance might not be clear to the uninitiated from the Independent's graphic alone.

Similarly, the figure given for the number of rapes reported to the police - 15,670 - can be found in the MoJ report, which makes use of police-recorded crime data.

As the report makes clear, the quality of the police-recorded crime data is often variable, as practice across different police authorities has changed over time. The figure could in fact be an over-estimate, as revisions to the data often lead to some offences initially recorded being re-categorised or removed from the records: in 2011/12 7.2% of all sexual offences initially reported to the police were subsequently removed.

When it comes to the number of cases which reach court, the figure quoted by the Independent is again to be found in the MoJ report, however we need to be careful about how we interpret it.

As the report notes:

"In 2011 the 2,900 defendants prosecuted for rape were prosecuted, on average, for 2.3 rape offences each."

So while it is accurate for the Independent to say that just 2,910 people were prosecuted for rape (1,070 successfully), it perhaps isn't the figure that we should be using to compare to the Independent's starting point: the 95,000 estimated rape cases. The 2,910 people prosecuted were prosecuted for appoximately 6,600 of these cases, according to the MoJ analysis.

Conclusion

While all the figures quoted in the Independent infographic are taken from the official data held by the Ministry of Justice, it doesn't account for the subtlety needed to properly understand them.

The 95,000 rape cases identified by the paper is the upper boundary to an estimate that includes attempted rapes, while the figures given for prosecutions and convictions refer to individual offenders, rather than the cases they are associated with, and therefore aren't directly comparable to the 95,000 figure.