Brookfield Infrastructure Partners LP (NYSE: BIP) and Emera Incorporated (NASDAQOTH: EMRAF) have some notable similarities. Both own energy generation, transmission, and distribution infrastructure in geographically diverse locations. Both distribute healthy amounts of cash flow to unitholders and shareholders, with distribution yields of 4.6% and 5.7%, respectively. Oh, and both have seen their stock prices slide by double digits in 2018.That could have income investors wondering if now's the time to buy these high-yield stocks.