Standardisation

The background characteristics sex, age, origin and level of education are not independent. The age structure varies across ethnic groups, for example: people born in the Netherlands with at least one parent born outside the Netherlands are relatively young. There is also a correlation between age and educational attainment. For example, older people are more likely than average to have completed only primary education or prevocational secondary education (VMBO). A multivariate analysis was carried out for each indicator, taking into account the correlation between the various background characteristics. For indicators based on survey data, this was done using a multiple classification analysis (MCA), and for the indicators based on register data, in most cases using a quantile regression. A different method was used for the indicators relating to income and wealth: a logistic regression analysis was carried out, in which the probability of having below-median income or wealth was regressed against the background characteristics.

The multivariate analyses produce standardised figures: these show the extent to which the outcomes for an indicator differ between the categories of a background characteristic (e.g. between age groups), if it is taken into account that differences between these categories are related to other background characteristics (e.g. level of education). In the visualisations, the original, unstandardised figures are shown in green and red. If a different colour is assigned on the basis of standardised figures, this is specified in the text.