Growing numbers of people in the second half of life are embracing entrepreneurship. Yet America’s start-up ecosystem of business incubators, accelerators and co-sharing workspaces largely ignores people over 60 who are eager to launch companies, either full-time or part-time in retirement. That’s why it’s worth looking at an experiment in Israel aimed specifically at this demo. And it’s why cities and states in America might want to create their own versions.