They've been permitted in my program if a project falls through after the proposal (I'm thinking of an instance where the student was recruiting for nearly a year on a successfully proposed project but only had about 1/10 of the participants she needed).
I knew quite a few people who have done meta analyses for dissertations. IMO, they're no less rigorous or time consuming than many traditional dissertation studies.
Can't say I've seen it - usually the places I've seen that allowed reviews to serve as dissertations did not have anyone with the qualifications to do a meta-analysis. That said, doesn't hurt to look into. As with most things, my primary concerns would be challenge and scope. If we're talking about a huge literature where you will be coding hundreds/thousands of complex studies, I think it would have the potential to be approved many more places than if we are talking about a small literature leading to 14 effect sizes and one moderator analysis (we had to do more than that for the final project in our meta-analysis class!).
We've had people do this, but they were large, full-scale meta-analyses. I believe that one person did a meta-analysis of a smaller literature and ended up having to do more than one for it to be approved (they did two related, but separate, meta-analyses).
hmmm, thanks so much for the information! I definitely acknowledge that meta-analyses are just as difficult as data-collection studies...the issue isn't me being lazy...the issue is more one of control. I'd like possibly do a meta-analysis because I would have much more control over it (less collaboration with the rest of my lab). Anyways, I guess if my current dissertation project falls through it's good to know maybe I can do a meta-analysis instead.