Discrimination varies between countries and is affected by particular local conditions. It is important to note differences: Not all Israeli Arabs are Moslem while I focussed on Swedish and British Moslems. African Americans are not a religious group but a skin-colour group. Israeli Arabs and African Americans are local minorities while in Britain and Sweden most Moslems are relatively recent immigrants.
In the course of looking for sources I found Moslem sites discussing some of these problems. One memorable quote said that there are more Phd's in France then in the entire Moslem world. Problems of inequality are not purely the product of discrimination and any comparison of data needs to factor that in.
This is what I found:
Members of ParliamentIsrael: 10/120 10% of seats vs 20% of population
UK: 8/650 1.2% of seats vs 4.8% of population
Sweden: 3/349 0.8% of seats vs (roughly) 4% of population.
USA: Senate - 0/100 African Americans are 13.6% of the population
Congress - 41/435 9.4% of seats
Taken together 41/535 7.5 % of seats
Executive (government ministers)Israel: None
USA: Head of State + 3
High CourtIsrael: 1/15
PrisonsIsrael: 3750 out of 22,000 (17% vs 20% of general population) An additional 7,000 were held from the occupied territories. 2008 10% os Israeli Arab prisoners were involved in political crimes.
UK: 11,000 out of 86,000 (13% vs 4.8% of general population).
Sweden: No data Non-Swedes form 30% of inmates and immigrants are reported to be disproportionately represented in the prisons.
USA: 900,000 out of 2.3m (39% vs 13.6% of general population) 2009
Israel: 56% vs 67% national average. 2013 elections.
UK: No data by religion but Bangladeshi and Pakistani voters were reported as having a higher then average turnout (70%+) . 65% national average. 2010 elections
Sweden: Studies suggest that voter turnout is lower among immigrants. Many immigrants are given residency but not citizenship.
USA: African American voters had a higher turnout then any other major ethnic group.