Many economists and lawmakers — especially conservatives — argue against tax hikes as solutions to entitlement shortfalls, saying the hikes would be counterproductive. According to this argument, higher taxes would retard growth, reduce federal revenues, and worsen entitlement shortfalls.

For example, Stephen Moore in his June 12 Wall Street Journal column “Don’t Know Much About History…” alludes to a presumed beneficial impact of faster (wage) growth on the financial problems of entitlement programs. Unfortunately, that presumption is incorrect, especially as regards Social Security.

The claim that faster wage growth would reduce Social Security’s financial shortfall is an artifact of the standard (but flawed) 75-year-ahead Social Security financial projections that count payroll taxes through that period but ignore benefit obligations those taxes would create beyond the 75^th year. The projections make it look as though robust wage growth would shrink the gap between Social Security revenues and obligations. But the picture changes over a longer timeframe.

The Social Security trustees have in recent years begun publishing estimates of the present value of Social Security’s financial shortfall in perpetuity. This is the correct measure to use in assessing the impact of faster wage growth on Social Security’s financial status because it is comprehensive — it accounts for all future taxes and benefits. Unfortunately, the trustees do not provide any analysis of how sensitive the perpetuity measure is to changes in various underlying assumptions.

Whether faster economic growth would improve or worsen Social Security’s actuarial deficit depends on the balance between two opposing forces: demographics and wage growth.

Concerning demographics, as retirees grow more numerous relative to workers, Social Security’s finances would worsen — which is easy to see if benefits depend on current wages.

Concerning wages, in each time period, benefits mostly depend on past wages. That’s because under current Social Security laws, once a person’s benefit level is determined at the time of retirement, its real value remains constant during the rest of the person’s retirement years because it is indexed to prices. (The real value of benefits would grow were post-retirement benefits indexed to wages instead.) Because current benefits depend mostly on past wages, faster growth in current wages won’t lead to a proportionate increase in current benefits. Benefits would begin to grow faster only after a considerable time lag. Hence, faster wage growth magnifies the financial advantage associated with this time lag and reduces Social Security’s actuarial deficit.

It has been shown that in the case of U.S. Social Security, the force of worsening demographics dominates: The system’s actuarial deficit (i.e., the ratio of the present value of the system’s financial shortfall to the present value of the payroll tax base when both are calculated in perpetuity) increases with faster wage growth — a result opposite to that obtained under 75-year-ahead calculations.

Thus, based on a comprehensive measure, the view that faster wage growth would deliver us from our Social Security problem is misguided. But many have repeatedly cited it to argue against reforming the program, e.g., Sen. John Kerry during his 2004 presidential bid.

The Social Security debate would be better served if we put this view in its rightful place: the trash bin.

Of course, the conclusion should not be that we should strive for slower wage growth to improve Social Security’s finances! Mr. Moore’s distaste for growth-retarding tax hikes is correct. But the negative implications of faster wage growth for Social Security’s finances do not provide any purchase for his argument. Indeed, the twin imperatives of maintaining high economic growth and resolving Social Security’s financial shortfall indicate — even more strongly — that reforms should be weighted more heavily toward future benefit cuts rather than tax hikes.