Average income

For each municipality the average disposable household income was calculated on the basis of data from the Regional income surveys of 1996 and 2004. For the sake of comparability the calculation of the household income was corrected for household composition. This standardised disposable household income was compared with the Dutch average which was set at 100 for both years. Then, at the level of the conurbation the difference between the central city and the other municipalities was calculated.

Example: the central city in conurbation X has a relative income level of 95 (i.e. 5 percent below the national average) in 2004. The other municipalities in conurbation x have an average income level of 103. The income difference between the city and the surrounding area is then 103 – 95 = 8 percent. If the difference in 1996 was 10 percent, the difference has decreased by 10 – 8 = 2 percent.

The incomes are calculated for the Dutch population living in private households. Among other things this means that student households are not included.