To be fair, the causality might not work in this direction, but if you want to know if you’re in a good market to buy, all you have to do is look at whether Millennials are moving to your town or not. According to RealtyTrac, buying is still more cost effective than renting in the majority (68%) of markets. But since 2007, the regions with the biggest influx of Millennials have had the biggest increase in housing prices — and more importantly, they’ve increase faster than rents in those same towns. So, start studying your Millennial demographics to figure out when to buy and sell.