The "40% higher conversion rates" for not requiring CVV is extremely suspect to me. Looking at the paper, it wasn't an A/B test, but comparing entire sites. There could be any number of variables causing a difference in conversion rates.
On top of that, there is no published date, but it does mention May 2007 being in the future. Six years is an eternity in the ecommerce space, and I have a feeling people are more familiar with what the CVV code is and where it is located today.
You're right that it's not proper A/B test, so it may be a case that correlation doesn't imply causation. Unfortunately, there's not a lot of research published with rigorous A/B testing for this kind of thing. If any of you out there would like to run an A/B test (and have us help detect fraud if you're worried about increases there), I'd love to help!
On top of that, there is no published date, but it does mention May 2007 being in the future. Six years is an eternity in the ecommerce space, and I have a feeling people are more familiar with what the CVV code is and where it is located today.