US Census Bureau headquarters The monthly decline in retail volume followed a modest gain in April, according to Census Bureau data. (Photo courtesy of HKS Architects)

WASHINGTON, DC—Retail sales in May posted their biggest monthly drop since January 2016, according to Census Bureau data released Wednesday. News of the 0.3% sales decline from April comes amid concerns that the economic recovery might not be strong enough after all for continued interest rate hikes by the Federal Reserve.