What do PhD programs, specifically finance and Econ programs, look for in research experience? I believe I have the pre-requisite GPA, GRE, tough classes, etc. to get in to a top PhD program in finance or economics. What I believe I am missing is the research experience.

What are these top programs looking for in the research arena, it's not exactly listed on their sites?

Is faculty supervised research experience a must have for a top 10 program? Or will independent research suffice?

If you have basically perfect attributes in the other metrics, does research experience matter too much?
This probably depends a lot on your definition of "top."

To get a sense for what successful applicants look like, check the websites, CVs, and/or LinkedIn profiles of current students in the programs you are interested in. (Look at their history from before they entered the program, of course.)

For example, I looked up the list of current econ PhD students at NYU Stern and started Googling. All the ones I checked (the first five names or so currently on that list) had some kind of formal research experience prior to joining the program.