Tag Archives: bad data

Politicians’ memoirs are ten-a-penny while books by statisticians in the House of Commons Library can be counted on one thumb. This is that book and its rarity makes it all the more valuable. We are familiar with the flood of Government statistics; what is less apparent to the reader is how the data behind the statistics was collected. This book exposes how unreliable such data can be and how it can mislead even well-intentioned politicians.

Sturge provides a number of examples. We remember Gordon Brown meeting Gillian Duffy in Rochdale during the 2010 General Election, but what Brown and other politicians did not appreciate at the time was the level of immigration to the UK from the A8 countries. This was because for decades immigration had been estimated using the Air Passenger Transport Survey which sampled travellers passing through Heathrow, Gatwick and Manchester airports, and this sampling had led to  estimates close enough to the decadal censuses that there was no good reason to change the sampling process.

What happened in the 2000s was that a Hungarian businessman Jóseph Váradi co-founded a low-cost airline, Wizz Air, which like other low-cost airlines, flew to small regional airports. The UK Government in anticipation of the A8 countries joining the EU had asked the statisticians for an estimate of the number of migrants from these countries coming to the UK and received a response of 5 to 13 thousand per year.

That had been based on an assumption that between 20 and 73 thousand per year would emigrate to Germany, but just before the enlargement the German Government had paused immigration from the A8 countries for two years. Not surprisingly many Eastern Europeans, particularly Poles, chose to come to Britain instead.

Unlike Germany, where any migrant has to register at their local Citizens Office within 14 days to live and work legally, there is no single action that a migrant needs to do in the UK and no link between National Insurance numbers and NHS numbers, nor are these linked to council records. As a result there is no easy way to make an estimate of immigration between censuses.

Another example Sturge uses from the Blair years is the change in agricultural subsidies from production to farmed area. Although land is registered on change of ownership, there were large areas of unregistered UK land: think of the land owned by the Crown, the Church, and Oxbridge Colleges. One consequence of the change is that it created an incentive to register land, even if it wasn’t actively farmed. In 2005 there were 100,000 applications to register land up from 9,000 previously.