Student ID
W2 First follow-up student analytic weight
X2 Student's sex
X2 Student's race/ethnicity-composite
X2 Mathematics standardized theta score
X2 Parents'/guardians' highest level of education
X2 P1-P2 relationship pattern
X2 Total family income from all sources 2011
X2 Socio-economic status composite
X2 Quintile coding of X2SES composite