The explanation owes much to simple economics, and may be a sign that worker pay will finally pick up more broadly amid the lowest unemployment rate since 2000. Sales of men’s clothes are surging as the industry shifts toward high-end boutiques with personalized service, and it’s boosting pay to attract skilled workers from the smaller pool of men who work in apparel retail. Compare that with women’s-specific clothiers, which bring in far more sales overall but are slumping and shutting locations across the country.