Factometer: fiction

The claim
“Some people talk as if net inward migration is rising. In fact, it is falling – down from 237,000 in 2007, to 163,000 in 2008, to provisional figures of 147,000 last year.”
Gordon Brown, podcast on immigration, 26 March, 2010

Cathy Newman checks it out
As you’d expect from a former chancellor, Gordon Brown is very fond of using figures to get his political arguments across. But as we found out just over a week ago he’s developed an alarming tendency to get his figures wrong.

So when he used a Downing Street podcast to make claims about immigration numbers, it was time to call in the team.

The analysis
Brown said in a podcast today that net inward migration (the number of people coming to the UK minus the number of people leaving) had fallen. According to the PM, the figures fell from 237,000 in 2007 to 163,000 in 2008 to 147,000 last year.

But he was drawing his numbers from two different sets of statistics.

The first two figures are the confirmed long-term international migration figures for 2007 and 2008 (although incidentally, he appears to have slipped with the first number – the published National Statistics figure is actually 233,000). We don’t yet have a comparable figure for 2009.

So Brown instead took a figure from the International Passenger Survey (IPS). This is used to compile the long-term international migration figures – but it tends to be smaller because it excludes asylum seekers and people who overstay their original visas.

If the prime minister wanted to be accurate he should have compared the 2009 IPS figure to the 2007/8 IPS figures.  They are 219,000 (year ended Dec 2007), 129,000 (year ended Dec 2008), 147,000 (year ended June 2009).

The sharp-eyed amongst you will see that there’s another reason to be cautious. The 2009 figure he quotes relates to the year up to June 2009. The 2007 and 2008 figures are for the year ending December.

It’s bad statistical practice to mix up time periods in this way because you leave yourself open to seasonal fluctuations in behaviour.

Stats watchdog the UK Statistics Authority is now looking at the figures, but could not comment on whether it would investigate further at time of writing.

A Downing Street spokesman said: “The immigration figures mentioned are published ONS figures. The prime minister was clear that the 147,000 figure was provisional.”

Cathy Newman’s verdict
Gordon Brown has done it again. The statistics he used for 2009 are an under-estimate, because they don’t include all migrants. The figures he used for 2007 and 2008, however, do.

So he’s misled the public by comparing the most flattering data for the latest year with the most unflattering data in the previous years.

The full year figures for 2009 aren’t yet available, so until we see them, we won’t know for certain if the prime minister’s claim that immigration is falling is true or not.

But he doesn’t have the figures to make that claim either. And in the meantime, the statistics we do have so far show that after falling in 2008, immigration is on the way up in 2009.