We could start with restrictions to the countries whose representatives dominate rape and other violent crime statistics. But as nationality isn't everything, further sorting of the criminals based on their culture, religion and ethnicity would also give more accurate info.
As for the economical effect, there has been some research done. In 2014, Swedish professor Jan Tullberg did some calculations and his results were that the annual costs of immigration and multiculturalism for Sweden alone were about 250 billion SEK (about $25,000,000,000) back then.
His research can be downloaded here.
Another study regarding Norway's situation also gets mentioned (page 101), and I think it's rather interesting reading:
In short, the average economical effects of different migrants during their lifetime in Norway go as follows:En norsk studie räknade på en bredare grupp invandrare med en högre grad av sysselsättning och kom fram till en genomsnittlig livstidskostnad på 4.1 miljoner norska kronor per invandrare från tredje världen. Studien är utförd av forskaren Erling Holmøy vid Norges statistiska centralbyrå och finns lättillgänglig som en serie artiklar i tidningen Finansavisen. [95] Västliga invandrare beräknades ge ett överskott på 800.000 och östeuropeiska ett underskott på 800.000 norska kronor under sin livstid. Invandring av utomeuropéer till Norge var 15.400 personer under 2012 vilket medför en förväntad framtida kostnad på 63 miljarder. Den totala framtida kostnaden för befintliga invandrare beräknades till 1.200 miljarder vilket sattes i relation till oljefonden som är på 4.100 miljarder norska kronor. Men vill det norska folket spendera oljefondens tillgångar på det sättet? I Sverige har vi inte någon oljefond och har därför ingen sådan möjlighet.
- a Western immigrant benefits the society for 800,000 NOK (Norwegian crown, or krone)
- an Eastern European immigrant costs the society 800,000 NOK
- 3rd world immigrant costs the society 4,100,000 NOK
- the total cost of already existing immigrants in 2012 is estimated to go as high as 1,200 billion NOK, which is almost 1/3 of Norway's total oil funds
I have no reason to believe that the relative costs would be significantly different in any other country.