The Government has said that it aims to reduce net migration “from the hundreds of thousands back down to the tens of thousands” by the end of the current Parliament. This is a somewhat rhetorical way for the Government to express its intention, as average annual net migration during the last Parliament was around 200,000 a year; so while it sounds like the Government aims to reduce net inward migration by a factor of ten, in practice they need to reduce it to around half its previous level to achieve net migration of less than 100,000 by May 2015.

So how far has net migration fallen since the current Government came to power? Ministers often say that net migration has fallen by a third, but it is helpful to look at the basis for this figure to fully understand how net migration has changed under the current Government.

Chart showing estimates of net migration from 2006 to 2013

The above chart shows estimates of net migration in the years ending each quarter, from the year ending June 2006 to the year ending June 2013. Estimates for years ending March and September have only been produced since 2010, which is why there are some gaps in the chart. (It’s important to remember that each of these migration estimates is based on data for the preceding twelve months, so even though estimates are now produced quarterly, each quarterly estimate shares data with the preceding and subsequent estimates. Only estimates in discrete twelve month periods are fully independent of one another.)

Net migration reached its highest level in recent years during the year ending September 2010, when it peaked at around 255,000. This was the second highest estimate of net migration ever recorded, just below the estimate of 260,000 for the year ending June 2005. Following the peak in 2010, net migration then fell over the next two years, reaching 154,000 in the year ending September 2012, which was the lowest estimate of net migration since the year ending December 2003. The fall from the peak in 2010 to the trough in 2012 was therefore around 101,000, which is a fall of more than a third from the peak, or around 40%. Since then, net migration has started to rise, reaching 182,000 in the most recent estimate, which is for the year ending June 2013. This is around 73,000 lower than the peak in 2010, and a fall relative to the peak of around 29%, or almost a third.

However, this comparison does not tell the full story about the longer-term trend in net migration. It is potentially misleading to compare the most recent estimate of net migration with its highest recent peak, as this is likely to overstate the extent of any long-term change in the broad level of net migration.

Net migration can vary considerably from one year to the next, and it is not uncommon for the estimate of net migration to change by tens of thousands between two adjacent years, even when there is no apparent change in the long-term trend. This is partly because of natural variation in levels of migration and partly because the estimates are survey-based, with a margin of error surrounding the net migration estimate of around +/-35,000, with a 95% confidence interval.

When recent estimates of net migration are compared with longer-term averages, the fall in net migration does not look so pronounced. The dotted black line on the above chart shows average annual net migration during the previous Parliament (based on the closest corresponding migration estimates, which are from the year ending June 2006 to the year ending June 2010). The most recent estimate of net migration (182,000) is just 14,000 lower than annual average net migration during the previous Parliament (196,000), which is a fall of around 7%.

However, this does not mean that the Government’s immigration policy has had no effect on levels of migration. What has changed during the current Parliament is the composition of migration flows. Net migration of non-EU nationals has fallen to 140,000, from an annual average of 194,000 during the previous Parliament. By contrast, net migration of EU nationals (including British nationals) has increased to 42,000, from an annual average of just 3,000 during the last Parliament.

Broadly speaking, reductions in net migration have therefore taken place among migrants subject to visa controls. Nationals of the UK and other EU countries are not subject to the same controls, but are still included within the net migration target. For this reason, Business Secretary Vince Cable recently described the target as “impractical”.

Finally, it is worth considering whether it really makes sense to express a reduction in net migration as a percentage. Suppose net migration were to return to being negative, which is what would happen if more people were emigrating than immigrating. It would not be particularly meaningful to express the change in net migration as a percentage of net inward migration in another period, as the reduction would be greater than 100%.

The next set of migration estimates will be published on the 27th of February 2014.

Author: Oliver Hawkins