The long-awaited 2018 edition of the Congressional Budget Office’s (CBO) Budget and Economic Outlook was released this month. It does not paint a rosy picture of the nation’s fiscal future, projecting $12.4 trillion in additional debt over the next decade. If past estimates are any indicator, however, that doesn’t reflect reality. Without a substantial change to the culture of overspending in Washington, the country’s fiscal situation is likely even worse. Ten years ago, CBO estimated that Congress would run a $151 billion surplus this past fiscal year. Instead, the country ran a $665 billion deficit. That’s in part because CBO conducts its...