OK, I confess. I’m addicted to browsing (and occasionally buying) in downtown Vancouver’s boutiques during my daily lunch-hour walks.On my budget, looking is half the fun. But whenever I buy something, I can do it with glib satisfaction instead of guilt and self-loathing. That’s because I’m supporting a local business, which helps our local economy.Right?Jeff Milchen thinks so. A co-founder and co-director of the American Independent Business Alliance, Milchen promotes movements that encourage shopping at local businesses. “Buy local” campaigns improve the bottom line for those shops. They also keep more money recirculating through the community.How do we know that? Take a look at a 2012 study published by the Institute for Local Self Reliance. The report, based on sales data from nearly 2,800 independent businesses, found 48 percent of the revenue spent in local businesses stays in the community. If you shop at a chain retailer, the study concluded, only 13.6 percent of your money sticks around.There, there. I’m not suggesting you give up on your Target store shopping sprees. Just tone it down a bit. Try to buy a few more items from local stores and send less local money back to Target’s headquarters in Minneapolis or other out-of-state locales.Milchen was in town last Monday to cheerlead members of the “Buy Vancouver” campaign. The movement is small but growing. If we embrace its message, we’ll give a boost to our county, which loses an estimated 40 percent in sales tax revenue to sales-tax-free Oregon. If we want strong businesses, we need to spend more time buying from local, independent merchants here at home.