Annex 1
DEFINITIONS AND
METHODS
A1. DATASETS
Secondary analysis of two datasets was undertaken.
The Poverty and Social Exclusion Survey of
Britain (PSE) was used to examine severe poverty and social
exclusion at a point in time. The PSE is a nationally representative
survey including information about 841 children aged 16 years
or less. Funded by the Joseph Rowntree Foundation, this cross-sectional
survey took place in 1999 and was designed and analysed by three
teams of researchers from the Universities of York, Bristol and
Loughborough. Fieldwork was carried out by the Office for National
Statistics. Among the surveys unique features were that it included
multiple measures of poverty and social exclusion for both children
and adults. Among the poverty measures were carefully constructed
and validated indices of material deprivation for both children
and adults that could be used to measure poverty separately for
children and adults. The survey also contained a more conventional
before housing cost measure of household income.
The British Households Panel Survey (BHPS)
was used in the analysis of severe and persistent poverty. The
BHPS is the only available data source that tracks the same households
and individuals over time. The BHPS allows an income measure of
poverty to be undertaken—again before housing costs—and
includes some indicators of social exclusion at the household
and individual adult level, as well as a Youth Panel questionnaire,
undertaken with 11-15 year olds since 1994, that includes many
useful indicators of young people's experiences both at school,
at home and with their peers. Nine waves of the BHPS were used,
from 1991 to 1999, which were the only waves available at the
time of the analysis for which net income data were available
at the time.
A2. Measures of Severe Poverty
A2.1. Severe Poverty in the PSE
In order to be considered as severely poor,
a child in the PSE analysis had to be:
— materially deprived according to
the child's material deprivation index;
— their parents had to be materially
deprived using the adult deprivation index; and
— their household income had to be
below 40% of the PSE median.
As an indication of the degree of poverty severity
which this definition implies, the average household incomes of
children defined as severely poor using this definition was £73
per week (below Income Support levels).
A2.2 Severe Poverty in the BHPS
The BHPS does not contain similar measures of
material deprivation to those in the PSE. In order to try and
achieve some consistency between the measures a harsh definition
of severe poverty was used. In order to be considered as severely
poor in the BHPS analysis, in any one year a child had to live
in a household whose income was below the median of the group
of children defined as in severe poverty in the PSE analysis.
This meant that children defined as severely poor in the BHPS
analysis were in households with incomes below 27% of median,
a severe income poverty line of £64.66 in 1999 (again, well
below Income Support levels).
A3. The Sample of Children from the BHPS
The construction of the sample of children for
the BHPS analysis was, inevitably, rather complex. First, it was
not possible to look at the whole of childhood because not enough
waves of the BHPS are yet available; a child aged less than one
year old when the BHPS began in 1991 would only have been eight
years old in 1999. Secondly, following all children born in 1991
would not have provided a large enough sample for analysis. As
a result, "phases" of childhood needed to be constructed
which had to be of the same length as each other, so that each
child's poverty experiences would be analysed over the same number
of years as every other child. The phases also needed to have
some sociological meaning. The phases chosen were 0-4 years, 5-9
years, 10-14 years and 15-19 years, to coincide approximately
with changes in children's lives around education. Each phase
of childhood is five years long, so that in all the analysis of
the BHPS children's poverty experiences are being examined over
a five year period, sometime in the 1990s.
Figure A1 provides further explanation of this
for the first two phases of childhood only, although exactly the
same principles apply to the third and fourth phases. The first
cross in bold on the figure represents children aged less than
one in the first Wave (1991) of the BHPS. Information about children
of this age in this year was analysed for 1991, 1992, 1993, 1994
and finally in 1995 when they were aged four years old. The same
procedure was applied for children aged less than one year in
Wave 2, and they were followed from 1992 through to 1996. For
the second cohort, a child aged five years in 1991 would be followed
from 1991 to 1995 and a child aged five in 1992 through to 1996,
and so on. All the children identified in this way were then combined
to provide a sample of over 2000 children, followed over various
five year periods between 1991 and 1999.
The important point to bear in mind is that
all children in the BHPS sample were followed for five consecutive
years between 1991-99, either between the ages of 0-4, 5-9, 10-14
or 15-19.
A4. MEASURING
PERSISTENT AND
SEVERE POVERTY
IN THE
BHPS
Using the definition of severe poverty for the
BHPS described in A2.2 above—children having incomes below
those of the median of children in severe poverty in the PSE—five
poverty states were identified over the five year period of childhood
on which the analysis was to focus. These are shown in Table A1,
which also shows the proportions of children who experienced each
of these states over the five year period.
Table A1. BHPS Poverty Measures
| % |
|
| Persistent and severe poverty: |
|
| three or more years in poverty, at least one year in severe poverty
| 3 |
| Persistent poverty only: |
|
| three or more years in poverty, no years in severe poverty
| 20 |
| Short-term and Severe poverty: |
|
| less than three years in poverty, at least one year in severe poverty
| 4 |
| Short-term poverty only: |
|
| less than three years in poverty, no years in severe poverty
| 18 |
| No poverty: | |
| child not in poverty in any years |
50 |
|
A5. Further Information
Further details about the methodology used in the report
can be found in Annexes to the published report or on request
from the authors.
Sue Middleton
Director
Centre for Research in Social Policy
Loughborough University
10 September 2003
| 
