Repositories for working papers in economics and finance I would like to post my working paper (broadly defined as theoretical work in finance) on a repository. 

Goals


Primary: to get a time stamp for a new idea that I have, such that I could establish the authorship and the date. 
Secondary: to get some attention to my new idea, receive comments and discussions, so that I could improve the paper.


Conditions


I would like to be able to post the paper myself and to have good control over updating it when I wish to, provided that a track record is kept (see my primary goal).
(The reason for focusing on easy updates is that the paper is still rather preliminary and changes will be needed. You could say, I should finalize it first and submit only then, and I get the point. But it has been sitting around for too long, and I do not want the idea in it to get stale. Perhaps receiving good comments on the preliminary version will quicken my progress.)


Situation so far


I have considered posting it in my institution's working paper series, but that process goes through a secretary which is always busy and would not normally accommodate requests of updating the paper in a timely manner. 
I have considered posting it on my own website, but then I do not get an official time stamp on the idea, and the visibility is low.


What could you recommend?
How about MPRA? After acceptance it would be cross-posted to REPEC, Ideas and Econpapers.