It would be tricky to test this, because you need to use a domain with hyphens where the original doesn't exist (and then you introduce new variables into the mix)
How one tiny hyphen destroyed our SEO efforts (2011)
11–20 of 35 posts
Re: How one tiny hyphen destroyed our SEO efforts (2011)
#12Re: How one tiny hyphen destroyed our SEO efforts (2011)
#13Re: How one tiny hyphen destroyed our SEO efforts (2011)
#14Re: How one tiny hyphen destroyed our SEO efforts (2011)
#15This makes me feel bad, I have a domain with a hyphen in it.
Re: How one tiny hyphen destroyed our SEO efforts (2011)
#16This is from 2011, the frictionless owls case study is well known to those who invest in domain names. Hyphens are a bad idea.
Tell that to experts-exchange.com
Re: How one tiny hyphen destroyed our SEO efforts (2011)
#17We recently had an internal debate about whether the anti-hyphen bias extends to the rest of the url. We haven't tested it though. I'd be curious if anyone has ...
Re: How one tiny hyphen destroyed our SEO efforts (2011)
#18We recently had an internal debate about whether the anti-hyphen bias extends to the rest of the url. We haven't tested it though. I'd be curious if anyone has ...
http://example.com/something-about-something ?
Matt Cutts actually recommends using hyphens in this case:
Re: How one tiny hyphen destroyed our SEO efforts (2011)
#19Re: How one tiny hyphen destroyed our SEO efforts (2011)
#20I don't know, there are so many factors that go into SEO that assuming, "Oh, it's the hyphen in the domain name" seems a little anecdotal to me.