edit to add - here you go:
The pay-as-you-go rule was originally adopted in 1990, during the last period of chronically high deficits, to prevent policy changes that would make the situation worse. It did not guarantee deficit reduction or freeze in place all tax and entitlement laws. It did, however, require that anyone proposing new tax cuts or entitlement expansions come up either with a way of paying for them without enlarging the deficit or with 60 votes in the Senate to bypass the rule.<1>
Requiring this simple trade-off had a powerful effect. As the Congressional Budget Office has noted, “Between 1991 and 1997, most new revenue and mandatory spending laws that were enacted were consistent with the PAYGO requirement to be deficit neutral.”<2> This deficit neutrality combined with spending restraint on discretionary programs and a strong economy to produce a budget surplus by 1998.
Congressional adherence to PAYGO began to decline once the goal of a balanced budget was achieved. But the main departure from PAYGO, before it was allowed to expire in 2002, occurred because of the enactment of large tax cuts in 2001. CBO has reported that of the more than $700 billion in PAYGO violations that Congress simply wiped off the official scorecard before PAYGO expired in 2002, “most of that amount stemmed from the estimated drop in revenues attributed to the Economic Growth and Tax Relief Reconciliation Act of 2001.”<3> This refutes assertions made by some opposed to renewing the original PAYGO rule that lack of fiscal discipline exists only or primarily on the spending side of the budget.
http://www.cbpp.org/cms/index.cfm?fa=view&id=933