Government workers cannot freely obtain secondary employment without authorization. Forcing them to take leave without pay is cruel and will affect this economy due to bankruptcy, default on loans and rents, demerits on their personal credit, and generally halt all kinds of economic activity that keeps our economy healthy. Private businesses are also hurt, such as childcare services, food service businesses located near federal agencies, and any business those workers normally would patronize. We owe it to them to pay them for time they would have been working through no fault of their own.
President Trump told the nation on national TV that he would shut the government down and take responsibility for it. This means paying the workers affected by his shut down.