Is household income a reliable measure when assessing educational outcomes? A Jigsaw of two datasets (Next Steps and National Pupil Database) for understanding indicators of disadvantage

Figures & data

Table 1. Completeness of data on selected household variables in Next Steps.

Household characteristics	Percentage of valid responses
Gross household income in wave 1	42
Gross household income in wave 2	5
Parental education	80
Household composition	97
Main parent employment status	98
Number of siblings	94
Housing tenure	97
Young person’s special educational need or disability	96

Table 2. Percentage of wave 1 respondents in each successive wave of Next Steps.

Wave	Year	Number of respondents	Percentage of wave 1
1	2004	15,570	100
2	2005	13,539	87
3	2006	12,439	80
4	2007	11,801	76
5	2008	10,430	67
6	2009	9,799	63
7	2010	8,682	56
…
8	2015	7,707	49

Note: in 2007 the original sample was boosted, especially for ethnic minority students, by 600 new cases. These are not included in the figures above.

Figure 1. Participant dropout and changes in household income over time.

Note: In wave 8, after a gap of 5 years, monetary incentives were offered for dropout cases from the original sample to respond.

Table 3. Completeness of data on selected individual variables in NPD 2005/06.

Individual characteristics	Percentage of valid responses
FSM status	75
Special Education Need or Disability Status	73
First Language	77

Note: the version of NPD available in linked form with NS is for 2005/06, the year after wave 1, once the NS data had been collected and cleaned

Figure 2. Percentage FSM eligibility (NPD) by decreasing household income band (NS).

Table 4. Percentage of young people from poor families identified as FSM-eligible (2004).

	Percentage labelled FSM-eligible	Percentage not labelled FSM-eligible
Household income <£13,480	16	84
Household income >=£13,480	2	98

Table 5. Percentage of young people from poor families identified as FSM-eligible (2005).

	Percentage labelled FSM-eligible	Percentage not labelled FSM-eligible
Household income <£18,000	13	87
Household income >=£18,000	1	99

Table 6. Summary of the included cases.

	Complete cases
Household income	9,700
FSM	7,977
KS4 results	8,308

Table 7. Correlation between indicators of disadvantage and KS4 attainment.

	Capped KS4 points
FSM eligibility	−0.15
Household income	+0.24

Table 8. Percentage correctness of predicting KS4 Level 2, based on income and FSM.

	Percentage correctness	Increase
Baseline	65.7	–
Step 1: Household Income	65.8	0.1
Step 2: FSM status	66.7	0.9

Table 9. Coefficient value.

	Coefficient value
Household Income	1.00
Not FSM-eligible	–
FSM-eligible	0.24
FSM data missing	0.44