How often are developers also the contractor?

I see that there are lots of "design/build" architects out there. Just wondering how often you guys come across developers that also act as the contractor/construction company.

when the developers do manage the construction in house, what type of firms are they usually? fee based/build to suit developers? developer owners? small regional firms? large national developers?

Curious, because as I've mentioned in other threads I have post MBA plans to start a development company and it seems like there would be a lot more money to be made if the developer also manages/performs the construction. Especially if they're developing for their own portfolio. Just looking for some insight to how people are currently doing things.

Do the capital providers generally prefer that construction is outsourced?

Thanks