Why does Warren Buffett prefer stocks over real estate?

Billionaire investor Warren Buffett said real estate is "much harder than stocks in terms of negotiation of deals, time spent and...involvement of multiple parties in the ownership". "When real estate gets in trouble, you find out you're dealing with more than just the equity holder," he stated. "There's...more opportunity, at least in...US...in...security market than in real estate," he added.