A quick (but by no means exhaustive) search of Google Scholar turns up a lot of articles which refer to Bob Martin's Clean Code, but I haven't personally seen any papers that cover a correlation between "clean code" and improved development.
However, think about your question for a moment. You are asking about improved development, and that in itself is a very broad subject area covered not simply by writing better code, but also by many other factors such as communication, managing expectations, methodology and streamlining processes, testing, continuous integration, and really the whole box and dice when you consider just how many things go into making a software development project successful, let alone improving on it.
So you question should probably be: does writing clean code contribute to improved software development? To answer that, the only "evidence" I could provide with would be entirely anecdotal, and for that I think the Clean Code book would be an excellent reference, as it is written not only by Bob Martin himself, but also with many chapters contributed by some of the smartest software developers out there. If that doesn't help, then perhaps a little cold hard logic might apply.
If you make a mess in your home, and you never get around to cleaning it, then living in your home will become a chore. It becomes harder to find things, harder to move around, and nobody in their right mind will want to visit you if you live in a filthy environment. The same too with code. If your code is a mess, you find it harder to located problems, let alone fix them. It becomes easier to justify a work-around that might not do the job, but hey, it sure beats having to wade through all that old legacy muck, right? In the end, just like never tidying your home, allowing your code to become untidy will cost you time, and effort, and created difficulties for you in the long run. Keeping your code clean however will provide you with a nicer platform to work in, make refactoring and debugging less of a chore, and will require you to worry less often about whether you'll be able to maintain your code easily over time.
No, I don't have direct evidence to give you, and these are merely the thoughts of someone who has been doing this stuff for a very long time, and who hopefully has earned a little software development wisdom along the way. :-)