Outbound links are important on your web pages. Black Hat SEO typically tries to create dozens of inbound links and sprinkle them all around, but what this achieves is that you have to constantly add more and more of these in order to hold rank, against others exploiting the same tactic, and Search Engines can probably figure out that you're stuffing the ballot box.
White Hat SEO on the other hand teaches that what we truly want, are authoritative pages to point at us. The higher the ranking of an authority, the more weight their inbound link to us weighs.
How do we get authoritative sites to point at us? By being authoritative ourselves, or at least looking like we are. Authorities cite their sources, and typically authoritative articles have many sources cited.
Citing your sources, with outbound links (to other sites) makes you look authoritative.
Hiring a dozen writers to create a thousand articles pointing at you, is probably more expensive and won't prevent a dozen good writers from pushing all your work onto page two, just by being authoritative. In SEO, Quality outweighs Quantity every time.
Notice the many outbound links I use in such articles as:
Outbound links make your articles more authoritative, and give you a much better chance to be linked to by other web sites.