Education and income inequality

A reader drew my attention to an article in the WSJ about educational achievement being both a driver and outcome of income inequality.

It appears there are plans to make the tests 'fairer' but the reasoning seems dubious.The writer concludes:

Family wealth allows parents to locate in neighborhoods with better schools (or spring for private schools). Parents who are themselves college educated tend to make more money, and since today’s high school seniors were born in the mid-1990s, many of the wealthiest and best-educated parents themselves came of age when the tests were of crucial importance. When the SAT is crucial to college, college is crucial to income, and income is crucial to SAT scores, a mutually reinforcing cycle develops.

And a similar pattern is replicated here. I extracted the following from the latest NZ Income Survey.

It shows the personal weekly income by estimated number in eligible population (000). Generally, the higher the educational qualification, the higher the personal income.

Highest qualification(7)	$1,190 & over	Under $210
No qualification	55.7	178.8
Lower secondary school qualification	40.2	83.1
Upper secondary school qualification	61.9	204.9
School qualification not specified	S	3.1
Level 1-3 certificate post-school	10.4	18.1
Level 4-7 certificate or diploma	184.9	79.7
Bachelor's degree (incl Honours)	191.2	73.8
Postgraduate qualification	117.6	25.8
Other post-school	33.0	28.3
Post-school not specified	6.3	5.2
Total(5)	706.6	706.7

(The seemingly anomalous figure in the second column is probably influenced by working-age females not in the workforce eg stay-at-home mums. Data comprises all individuals aged 15 and over)