Game show winners choosing between two equally desirable prizes will choose either the one that is more expensive or the one with which they are more familiar  Today' s winner, Ed, is choosing between two equally desirable and equally unfamiliar prizes, A and B
He will thus choose A, which is more expensive
With a book contract, an academic writer receives either an advance or a guarantee of royalties. Professor al-Sofi received an advance for a book contract, so al-Sofi did not receive a guarantee of royalties.