When writing a literature review, more specifically writing a summary for a source, is the use of quotes frowned upon versus paraphrasing? Whereas I normally paraphrase information when I use a source for my literature review, I occasionally insert quotes (not to emphasize the information within the quote). All the reviews I've looked at so far tend to use quotations as little as possible. My question is whether it is discouraged or encouraged to present information through a variety of ways (ie. paraphrase, quotes, etc.)?

For instance: 

In looking at the relationship between immigrants in the Netherlands and the Dutch economy, Rootenberg et al. (2003) drew upon findings comparable to that of previous research results found in Sweden: while the impact varied across different immigrant groups, the average impact was inconsequential. Among the groups that produced a net gain were immigrants who arrived at a young age and those coming from a western society; all other groups represented a burden to the public sector. Hansen et al. (2015) and Gerdes et al. obtain similar results for Denmark. Their findings are summarized as follows: “Immigrants from richer countries have a positive fiscal impact, while immigrants from poorer countries have a large negative one. The negative effect is caused by both a weak labour market performance and early retirement in combination with the universal Danish welfare schemes" (Hansen et al. 2005).
In general, paraphrasing authors is better than quoting unless they say something truly unique and their exact words are needed to convey their ideas. In a literature review, you may find yourself needing to quote more often because of this reason (for example, historian Gary Dickson coined the term "Mythhistory," which is not something I have heard other scholars use).

Many times in undergraduate writing, students will use several quotes in order to make their word count higher. In higher levels of academic writing (like journal articles or books), some publishers will not print your work if you include too many quotes. (A former professor of mine had to write a letter to his publisher to justify adding a total of two block quotes in his 80,000+ word book.)

I think the most important thing about using quotes is to explain them. To say that so-and-so said "important thing" isn't enough; your interpretation and justification of the quote is needed. I personally think your example in the question would be better paraphrased rather than quoted because the way the authors worded their finding is not too unique. If there is some specific wording from this that you would like to interpret, then I would say quoting is better.

I would suggest not arbitrarily quoting. If you can strongly justify using a quote then I would do so, otherwise paraphrasing is generally better.