According to this article in The Economist (leans free-market/deregulation) regarding refugees in Germany:
Evidence suggests that immigration has only a small impact on employment or wages.
...but also points out several caveats and concludes with:
Of course, these figures are highly uncertain, and depend on how many more refugees arrive, how quickly their asylum applications are processed and how soon they find jobs. Governments can make their impact more benign by accelerating all those steps.
This article from PBS regarding refugees in the US mentions:
For the U.S., on net, it’s positive, because there are gains when people come, add to the labor market, add skills and generally, earn less than what they can contribute to the society as a whole. So there are benefits, but there are distributional consequences that can be quite complicated.
The Brookings Institute (leans liberal) has this to say about Syria and Lebanon:
So assume you are in a country that has taken in a quarter, or even 2.6 percent, of your population as refugees fleeing war and prosecution. Would your economy collapse? Last time we checked, that was not quite the case. The Lebanese economy has been growing beyond expectations over the past two years
Conclusion? Not sure there is one. Seems to be plenty of analysis out there but no groundbreaking conclusive results one way or the other. My non-economist opinion is that it's a complex topic and would depend heavily on the specifics of each nation and each refugee population.