Tambo in Chelsea opened in early March with a menu full of Peruvian-inspired cuisine and craft cocktails. Now it's preparing to shut down next week for the winter, and owner Jose Duarte is hoping they can reopen in the spring. It would be better than his other restaurant, Taranta, which he closed for good after 20 years in Boston's North End.Duarte hoped he could keep Taranta open with help from the federal Paycheck Protection Program.But the terms of the loan meant he had to use most of it for payroll, and, like many restaurants, that's not the biggest expense. Duarte was paying $14,000 a month just to rent the North End space for Taranta."I think that from the beginning, those loans were not fit for us," he said. The Paycheck Protection Program was launched early in the pandemic to get a lot of money — ultimately $525 billion — to businesses nationwide, and get it to them quickly.Massachusetts companies received loans ranging from $10 million, all the way down to a few hundred dollars, for a total of about $13 billion loaned so far to Bay State businesses.But the program was designed to support businesses' payrolls. Research by MIT Sloan School of Management professor Lawrence Schmidt said the loan formula ended up favoring certain industries, not necessarily ones most affected by the pandemic."The way we designed the Paycheck Protection Program had a bit of a design flaw," he said. "The hardest-hit sectors actually tended to receive the least amount of aid." Industries that were able to adapt to the shutdown — think white-collar workers who could more easily shift to working from home — benefitted more from the Paycheck Protection Program than industries that couldn't shift to working from home, Schmidt's research showed. Another problem: Those white-collar employees are generally higher paid — think information technology or biotech workers — and lower-income workers couldn't continue their jobs and were laid off.The problem was magnified in Massachusetts, where we have a relatively large amount of higher-wage white-collar workers. Schmidt's research shows that industries classified as "professional, scientific and technical services" received $2 billion in Paycheck Protection Program loans in Massachusetts, breaking down to $15,000 per worker.In contrast, the hard-hit hotel and restaurant sectors got $1.2 billion in Paycheck Protection Program loans in Massachusetts, or about $6,000-per-worker."If you think about a good insurance program, you should be sending the largest checks to the hardest-hit groups. If someone person's house burns down, they should probably receive a larger check than someone who breaks a window," Schmidt said.Schmidt says the next round of the Paycheck Protection Program should take a more targeted approach."Clearly, with the benefit of hindsight, going forward, we can do better with the policies we design. We should help firms, but we should do so in an intelligent way," he said.