Re: Opportunity cost?
"Substitute "Facebook" with "The Internet", and you might be on to something."
Hahaha. The Internet. Reduced productivity. Right. Hopefully Tim will be along with some numbers, but the Internet is responsible for massively lowering costs and this hugely increases productivity. It has also revolutionized entire fields, such as science. The incredible explosion in new science and mathematics that has been caused by the Internet (easy access to literature, e-mail, Skype conversations, even down to something so simple as making it easy for me to book flights to conferences) will make long-term GDP trends significantly increase.