Better High-Yield Dividend Stock: Pfizer vs. Merck

Investors looking for ways to pump up their passive income streams might want to turn their heads toward the pharmaceutical industry. At recent prices, you can buy shares of Merck (MRK -0.88%) that offer a yield above 3%, and shares of Pfizer (PFE -0.35%) offer a yield above 6%.Which of these two high-yield dividend payers is best for your portfolio? Let's weigh their strong points against some of the challenges they face, to see which stock is a better buy now.The case for MerckShares of Merck have fallen ...