Mexico Runs on Sidewalk Economy

The underground economy looks more like a release valve for entrprenurialism in Mexico. I'm not sure it's good or bad. The important thing for them is to make sure that collect somes taxes. How would you do this? I bet the financial/banking system has much to do with the problems. Poor access to capital means that folks have little possibility of getting a business loan. No loan means, they try to scratch out a living as a vendor is a stall (versus a storefront). Vendor means cash, means nothing for the tax collector.