February 2010

Media information: Embargo 00.01am Monday 22 February 2010

Migrating away from reality

UCL statistician calls for immigration data to be served raw - however politically unpalatable.

In 'Not 'challenging myths' but mythical challenges', UCL Emeritus Professor Mervyn Stone exposes the way in which political agendas are playing a significant role in the presentation of official statistics.

Nowhere does this politicisation apply more readily, Professor Stone argues, than on data relating to immigration.

As a highly charged political issue, immigration is particularly susceptible to data 'management'.

Stone illustrates the 'vulnerability' of immigration data in a penetrating critique of 'Sleepwalking to segregation'?: Challenging myths about race and migration by two University of Manchester social scientists, Nissa Finney and Ludi Simpson. A book that claims to expose seriously damaging errors in statistical arguments, with MigrationWatchUK a primary target.

Yet playing them at their own game, Stone unravels the way in which Finney and Simpson's 'academic' analysis of MigrationWatchUK's presentation of immigration figures falls into the very types of traps they claim to be concerned about.

The accusation

Finney and Simpson's accusation is that immigration data are being hijacked for political purposes. They attack MigrationWatchUK on the basis of its 'inaccurate use of statistics ... playing with figures to find a large number to quote'. This is done, Finney and Simpson argue, 'to make a political case' - against immigration:

'A key component of MigrationWatchUK's anti-immigration argument is immigration's detrimental effect on the economy ... although immigration results in economic growth it is cancelled out by the increase in population ... Using this reasoning, MigrationWatchUK has challenged official statistics on the economic impact of immigration'. (p4)

Own goal

The irony Stone points to is that Finney and Simpson are doing exactly that which they accuse MigrationWatchUK of doing - the only difference is that their agenda differs. Professor Stone demonstrates this by presenting a forensic, step-by-step analysis of the statistical semantics and logic of 'Sleepwalking to segregation'? to argue that Finney and Simpson themselves have distorted the facts.

For example, Finney and Simpson dispute the claim that: 'In the 1990s, immigration became the most important component of population growth (accounting for 83%)' as both 'false and peculiar'. However Stone disagrees, citing the original source as the Government Actuary's Department [GAD] projection for the period 2003-31:

'The overall effect of immigration would (under the assumptions made) account for 82.9% of the population increase in the 27 years'.

Professor Stone also argues that the Home Office's claim that immigration contributes £2.5 billion per year towards GDP (Gross Domestic Product), which is endorsed by Finney and Simpson, is inflated. Instead, according to Stone, when calculating immigration's contribution to GDP, 'per capita GDP' is a better measure than GDP because it takes account of the fact that immigration increases not only GDP but also population. (p9)

Call for neutrality

Stone's point is that immigration data is being massaged. One of the key dangers of data's potential for manipulation is that political 'inconveniences' can be dismissed by simply 'discrediting' statistics which weaken the status quo. Professor Stone illustrates the need for academic procedure which removes room for manipulation. Stone credits Finney and Simpson's accusations as 'welcome because they are bold and explicit and because their statistical targets are, in the end, clearly specified'. The alternative being, he argues, simply writing data off on the basis of a political viewpoint.

Mervyn Stone urges 'detailed scrutiny and analysis' of statistical publications and says that it is of the utmost importance for statisticians to present data on immigration without misrepresenting the evidence for a political motive.

Ultimately, data need to be served raw, rather than 'cooked up' according to what's on the political menu.

For more information contact:

Mervyn Stone on 01895 674 715 or mervyn.stone@yahoo.co.uk

Notes for Editors

i. 'Not 'challenging myths' but mythical challenges' by Mervyn Stone can be downloaded here.

ii. Civitas is an independent social policy think-tank. It receives no state funding either directly or indirectly and has no links to any political party.

iii. The views expressed in the report are those of the author, not of the Institute's.

iii. Professor Mervyn Stone is Emeritus Professor of Statistics at University College London.