§ Mr. Cousins
To ask the Chancellor of the Exchequer if he will estimate the distribution of(a) households and (b) taxpayers in each quartile of income in the United Kingdom and in each of the regions and nations of the United Kingdom. 
§ Mrs. Liddell
The information requested falls within the responsibility of the Chief Executive of the Office for National Statistics. I have asked him to arrange for a reply to be given.
Letter from Tim Holt to Mr. Jim Cousins dated 21 January 1998:531WThe Chancellor of the Exchequer has asked me to reply, as Director of the Office for National Statistics (ONS), to your recent question asking for the distribution of (a) households and (b) taxpayers in each quartile of income in the United Kingdom and in each of the regions and nations of the United Kingdom.The figures requested are in the attached tables. Owing to the nature of the question, it has been necessary to use two different data sets to produce the answer. This means that the figures for the two parts of the answer are compiled on different bases and are not strictly comparable.
(a) Distribution of households for each income quartile of individuals in Great Britain, split by region Standard region Bottom quartile Second quartile Third quartile Top quartile (percentages) Total households (=100 percnt.)(millions) After housing costs North (including Cumbria) 30 27 25 18 1.4 Yorkshire and Humberside 27 27 24 23 2.0 North West 28 26 25 22 2.5 East Midlands 24 26 25 24 1.7 West Midlands 25 26 25 24 2.1 East Anglia 24 24 25 28 0.9 Greater London 31 19 17 33 3.0 South East—excluding London 21 20 24 34 4.4 South West 27 26 23 24 2.0 England 26 24 23 27 20.0 Wales 29 26 26 19 1.3 Scotland 27 26 24 23 2.0 Great Britain 26 24 24 26 23.4
1. The data come from the Department of Social Security's Households Below Average Income (HBAI) Series, based on the Family Resources Survey (FRS) for the 1995–96 financial year and covering Great Britain. Data from the FRS were used to answer this question because it has a considerably larger sample size than the alternative data source, the Family Expenditure Survey (FES), enabling statistically more precise results to be obtained. The FRS covers only Great Britain, so no estimates are available for Northern Ireland.
2. The income measure used is weekly net (disposable) equivalised household income. The definition of income used follows that in the HBAI series for FRS based results; figures are given both before and after housing costs in line with usual HBAI practice.
3. It should be noted that the HBAI series does not take regional price differences into account.
4. Each quartile of the income distribution contains exactly 25 per cent, of all individuals in Great Britain. Due to different household sizes, each quartile group does not necessarily contain 25 per cent. of all households.
Households Below Average Income (HBAI)
(b) Distribution of taxpayers for each income quartile of households in the United Kingdom Bottom quartile Second quartile Third quartile Top quartile (percentages) Total taxpayers United Kingdom 9 21 33 37 100
1. In this part of the answer, each quartile group contains 25 per cent. of the households. The figures show the proportion of all taxpayers in the households in each of the quartile groups.
2. The data come from the Office for National Statistics' Effects of Taxes and Benefits on Household Income series, based on the Family Expenditure Survey for the 1995–96 financial year and covering the United Kingdom.
3. Data from the FES were used to answer this part of the question as the information about taxpayers was not available on the FRS database. Accurate estimates of the distribution of taxpayers by quartile for the regions and countries of the United Kingdom could not be obtained from the FES because of its small sample size.
4. The income measure used to rank the households is equivalised disposable household income. For a complete definition, see Economic Trends, Number 520, March 1997.
Family Expenditure Survey.