Luxury shoppers appear to be increasingly “trading down,” creating significant growth in the off-price retail market. Placer.ai, which tracks foot traffic via cell phone data, calls it a “horseshoe effect,” noting that luxury is likely to remain popular among higher-end households, but its reliance on a smaller customer base may limit growth. “Luxury may be more visible than ever, with social media fueling brand awareness,” the analysis says, “while off-price chains (are) positioned to capture continued traffic gains from value-driven shoppers and even affluent consumers.” The median household income for luxury shoppers increased slightly to $118,000, while off-price shoppers have a household income of about $75,000 — slightly below the national average.