That analysis has been done and the conclusions are devastating for the tax office.

https://www.consultancy.nl/nieuws/39000/pwc-belastingdienst-... (dutch)

Devastating? I don't see anything devastating in the article you linked. Perhaps you can point it out? The language is very weak.

> PwC considers it plausible that the people who ended up on the blacklist on the basis of appearance or nationality were disadvantaged as a result. Like others on the list, they presumably did not qualify for smooth debt restructuring, debt forgiveness, or a personal payment arrangement. Unlike in the allowance affair, according to PwC, the list played no role in the assessment of income tax returns.

aannemelijk vermoedelijk

They can't point to a single case in which this happened?

You could of course start with the first paragraph:

"Bij het inschatten van frauderisico’s beoordeelde de Belastingdienst zeker tientallen mensen op hun nationaliteit en uiterlijk, zo blijkt uit onderzoek van PwC. Zo kwamen de mensen terecht op de Fraude Signaleringsvoorziening (FSV), beter bekend als de zwarte lijst."

So what could cause a causality between income/country of origin and fraud probability?

Is fraud genetic? I don't think so, so it's only a correlation at most.

Income and social mobility might corralled with fraud.

Country of origin might cause low income and low social mobility.

Unintentional fraud is probably way higher among immigrants, it is hard to avoid "fraud" when filling in forms if you don't understand all the rules, even worse if the form isn't even in your native language.

There is no "Unintentional fraud". If it's unintentional, it's a mistake. See also:

https://www.merriam-webster.com/dictionary/fraud