[croes]

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.

[danamit]

Income and social mobility might corralled with fraud.

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

[Jensson]

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.

[einpoklum]

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

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