Members of Congress don't have a lot of incentive to avert government shutdown when they will continue to get their paychecks right on schedule. When factions of Congress refuse to compromise to reach an accord, they are failing to do what they were elected to do. In short, they aren't doing their job. When the rest of us don't do our jobs, we don't get paid. Let's make it so the same is true of Congress.
Why is this important?
The government has shut down for the first time in seventeen years. Congress is broken, and they have no incentive to break the gridlock. We need to incentivize them to compromise, which means that they should suffer the same fate as hundreds of thousands of government employees: furloughs. It is unethical for Congress to be making decisions for others that don't actually affect them personally.
