As the Joint Select Committee on Deficit Reduction (widely known as the “supercommittee”) begins its work, many have asked what we would counsel based on our work last year as co-chairmen of the president’s fiscal commission. We can summarize this advice in seven words: Go big, be bold and be smart.

The stakes for this committee are very high. If the panel is unable to reach agreement on a credible deficit-reduction plan, and the across-the-board cuts agreed to in the August debt-ceiling deal are allowed to take effect, the consequences to our economy and our political system would be serious, if not devastating. Such an outcome would produce not only bad policy, by cutting spending indiscriminately without setting priorities, but would further undermine public and market confidence in the political system’s ability to resolve problems.

Given the tremendous challenges the committee faces and the dire consequences of failure, some have questioned why we and others have called on its members to reach an agreement that goes well beyond the goal of $1.5 trillion in deficit reduction. We believe that going big could actually improve the chances of success, in terms of the politics and the economics of debt reduction.

We have called for at least $4 trillion in savings because it is the minimum amount of deficit reduction necessary to stabilize the U.S. debt and put it on a downward path as a percentage of gross domestic product. A package that achieved $1.5 trillion in savings would generate a great deal of opposition from affected constituencies but would still leave in place a large and growing debt burden.

When we presented our co-chairmen’s proposal to the rest of the fiscal commission in November, Washington insiders were shocked that we so aggressively exceeded our mandate. They were sure that the proposal would need to be scaled back to get a majority vote. It turned out that the opposite was true. The more comprehensive we made it, the easier our job became. The tougher our proposal, the more people came aboard.

Commission members were willing to take on their sacred cows and fight special interests — but only if they saw others doing the same and if what they were voting for solved the country’s problems. This spirit of shared sacrifice gained us broad bipartisan support, spanning from Democratic Sen. Dick Durbin to Republican Sen. Tom Coburn. We would not have garnered that type of support had we not taken on defense, domestic programs, the solvency of Social Security, health care, and spending in the tax code all at once.

The supercommittee’s work is not simply arithmetic. Its members must be smart in how they achieve savings. They should avoid making immediate deep cuts that would jeopardize our fragile economic recovery. They need to set priorities, such as reducing lower-priority spending while preserving funding for key investments necessary to compete in a knowledge-based global economy. And they should not make cuts that would harm the disadvantaged.

We are encouraged that President Obama has embraced the goal of stabilizing the debt and the target of achieving at least $4 trillion in deficit reduction. Unfortunately, his proposal falls short of this goal by counting war savings that were already planned; and while it does (barely) stabilize the debt, it does so at a dangerously high level and with no margin for error. We are disappointed, too, that the president did not address the long-term solvency of Social Security. Nonetheless, it represents a step forward.

The president has said that he won’t support major cuts to entitlements unless the package includes additional revenue, but the opposite must be true as well. The president must be willing to support real savings in entitlements that deal with long-term costs. We can’t simply cut or tax our way out of this problem. Bringing our debt under control will require tackling the growth of entitlements and reforming the tax code to promote economic growth and generate enough revenue to meet our commitments.

The work done by our commission and others has shown that it is possible to reform entitlement programs in a way that preserves and even strengthens the safety net for the most vulnerable while achieving significant savings. Similarly, by pursuing comprehensive tax reform that eliminates or reduces many of the $1.1 trillion in tax expenditures, we can raise revenue in a way that improves progressivity in the tax code — because these tax expenditures disproportionately benefit upper-income taxpayers — while promoting economic growth by removing economic distortions from tax expenditures and reducing marginal tax rates.

If the supercommittee is bold, it can put forward a smart, well-formulated deficit reduction plan that not only reduces our deficit but also maintains our economic health and restores public confidence in America’s ability to govern wisely and prudently. Failure to do so will incur a great price.

Alan Simpson, a former Republican senator from Wyoming, and Erskine Bowles, who served as chief of staff to President Bill Clinton, served as co-chairmen of the National Commission on Fiscal Responsibility and Reform.