Why so many tied for First?

Have you noticed how many players are tied for the first place these days at major Chess tournaments? Even towards the closing stages? This happened at Corus Wijk Aan Zee and now at Gibraltar. Six players were tied for first before the final round in the Group A of the Corus tournament. Only in the last round did an eventual sole winner emerge. Five players are tied for first before the final round of the Gibtelecom tournament even though Elite GMs such as Svidler, Gashimov, and Nakamura are playing. Is it the worldwide recession and a safe approach by the players? Please leave Nakamura out when you put on your thinking hats:)

What do you think is the reason?