> Religion plays a significant role in influencing corruption levels [26,[29], [30], [31], [32], [33]]. While all religions encourage good moral conduct and ethical behavior, studies show that different religions are associated with varying levels of corruption. Notably, countries whose primary religions are hierarchical religions such as Catholic Christianity (Catholicism), Eastern Orthodox Christianity, and Islam, tend to have higher corruption levels, particularly in comparison to Protestant Christian countries [21,30,[34], [35], [36], [37]]. Supporting this claim, [30] found that corruption levels are lowest in countries with a Protestant majority and highest in countries with an Orthodox Christian majority.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10360949/
To disentagle communism you can look at 1800. But there you have other confounders (colonialism, industrialization, feudalism...)
Ukraine is more complicated, a nation sewn together from very different regions; Greek Catholics are an important minority, mostly present in the formerly Austro-Hungarian western part of the country, which also seems to be the most nationalist one.
