The rules require that offsets for spending increases or tax cuts must be found within a 10-year budget horizon, but they also exempt a number of significant tax and spending programs. Putting aside these details of implementation, given current budgetary challenges, the key question is whether the traditional PAYGO approach is sufficiently ambitious.
At its best, PAYGO prevents new tax cuts and mandatory spending increases from making projected budget deficits worse; by construction, PAYGO does not require the Congress to reduce the ever-increasing deficits that are already built into current law. Many other countries have experience with fiscal rules.