A study from 2013 funded by the European Union concludes that there is no evidence supporting claims that immigration increases crime or unemployement. Although a lot of time has passed since then, the conclusions drawn continue to hold to this day.
In other news, water is wet, the sky is blue on a nice day, and summer in Finland comes with relatively little snow. I recommend everyone read the linked articles; they touch on quite a few important issues all at once.
Unsurprisingly, the first article also raises the point that immigration does not increase the unemployment rate (and a loss of immigration can lead to labor shortages). Immigrants also tend to take jobs that are unappealing to locals, but nevertheless important to the functioning of the economy. All of this is totally unsurprising, but also bears repeating given the extent to which existing stereotypes of immigrants and immigration still hold sway in public discourse and politics.
My attention is also drawn to the second sentence of the second paragraph of the older article: "The conclusions suggest that immigrants are not the cause of an underground economy, but that if such an economy already exists, it encourages migration." This conclusion is not an indictment of immigrants or immigration, but simply an obvious consequence of policy and bureaucracy making participation in the above-board economy prohibitively difficult for outsiders: if the only practical way to get essential tasks done on an acceptable timeframe is through the black market, then of course that is what people will do. The same phenomenon arises in the context of marginalized professions such as sex work, where business gets done outside of the traditional financial system because using the traditional financial system was not an option.
More generally, these studies strongly support the conclusion — widely accepted in very progressive circles, but often ignored even in otherwise "liberal" spaces — that all of the problems associated with immigration result from direct and indirect harm done to immigrants by intolerant or inflexible local institutions and people. We need to do more to help immigrants integrate into society as quickly and seamlessly as possible.
And above all, we need to make sure immigrants continue to come. A country without immigration will ultimately suffer the fate of a fully closed ecosystem, or a business that neither hires employees nor acquires new customers: stagnation, then collapse. Neither Finland nor Europe can afford that.