Stack Exchange has recently rolled out the new user indicator. Given that this comes with a reminder on the comments and answer sections, this is presumably intended to get people to be nicer to newer contributors in their answers and comments. I also take this as an indicator that Stack Exchange is looking to improve retention of new users.
So are rude comments actually the problem for new users? I posit that it's actually worse, from a user retention perspective, to down-vote a new user and not say anything than to give a rude yet informative comment. Even something as rudimentary as pointing them to the FAQ or saying that opinion questions are out of scope gives them feedback that they can use to improve rather than telling them that they suck with no other information (down-votes with no comments). Additionally, downvotes can snowball. When you read answers with even a single downvote, you likely come in with the bias that the answer is bad, and are therefore less likely to read it in a favorable light.
I'm not proposing requiring a comment with every downvote. Instead, I'd like to consider something much more specific: requiring a comment when casting the first downvote on a post by a new user.
Do the data support this idea?
Ideal data would be numbers on the following three things:
The number of users whose first post was downvoted who then made additional posts over a week later
The users in (1) with the additional condition that there was a comment on their first post
The fraction of downvoted posts that have comments
EDIT: I'm looking for data not opinions. This is not yet a feature request. I'm already aware that people don't like the idea of mandatory comments, as I did my research before asking. I'm looking for whether or not there is data on user behavior on stackexchange if possible or a related site if not.