Instead of having government spending and revenue determined by officials who appear to prefer being re-elected, say we set up a supreme court of government budgeting and revenues.
We observe incentive bias in elected officials when budgeting (legislative pork) and when determining tax (highly specific tax breaks). We can reduce this incentive bias via the same mechanism as the Supreme Court, i.e. tenure for life. This new panel would weigh out the merits of budget requests and determine what taxes were needed. Like the court, they would detail their arguments pro and con.
This will never happen, though. When would publicly elected officials ever vote themselves less power?