In their debates, ads and speeches, the candidates for the Republican presidential nomination are vying for the label of most Reagan-esque.

On taxes, “I take the Reagan approach,” former senator Rick Santorum said at a recent Florida debate.

On the economy, “under Ronald Reagan, we had . . . the right laws, the right regulators, the right leadership,” former House speaker Newt Gingrich said in a debate before his South Carolina primary victory.

Judging from the candidates’ tax proposals, they seem to believe that the most Reagan-like candidate is the one with the biggest tax cut. But as the person who drafted the 1981 Reagan tax cut, I think Republicans misunderstand the premises upon which Reagan’s economic policies were based and why those policies can’t — and shouldn’t — be replicated today.

I was the staff economist for Rep. Jack Kemp (R-N.Y.) in 1977, and it was my job to draft what came to be the Kemp-Roth tax bill, which Reagan endorsed in 1980 and enacted the following year. Kemp and Sen. Bill Roth (R-Del.) proposed cutting tax rates across the board by about a third, lowering the top rate from 70 percent to 50 percent and reducing the bottom rate from 20 percent to 8 percent. (Though when the Reagan tax cut was enacted in 1981, the bottom rate was reduced to 11 percent.)

While our aim was to increase growth and employment, we were intent on doing so in a way that did not exacerbate inflation, which was the nation’s top problem.

After all, growth was not particularly sluggish in the late 1970s — the economy grew at 5.4 percent in 1976, 4.6 percent in 1977 and 5.6 percent in 1978. (We haven’t seen three consecutive years as good since.) But people didn’t feel very prosperous because inflation and unemployment were high. The unemployment rate was around 7 percent during those three years, and inflation accelerated, going from 4.9 percent in 1976 to an astonishing 13.3 percent in 1979.

We believed that inflation contributed to unemployment because when workers got cost-of-living pay increases, they were pushed into higher tax brackets. In turn, this required them to ask for bigger pay increases to try to maintain their after-tax income. This cycle increased the cost of employment for businesses and discouraged them from hiring more workers.

According to the Tax Policy Center, the total federal tax rate (including both the employer and employee share of the payroll tax) for a four-personfamily earning the median national income more than doubled between 1965 and 1979, from 11.5 percent to 23.1 percent. The marginal tax rate — the tax on each additional dollar earned — rose from 17 percent to more than 36 percent. This “tax wedge” — the difference between a business’s cost of employment and the employee’s after-tax reward — also explained why unemployment was high despite robust growth.

Keynesian economics, which was the dominant theory at the time, said that higher taxes would curb inflation by reducing people’s disposable income and spending, and that any tax cut would exacerbate inflation. Our thinking, by contrast, was that lower taxes would increase the incentive to work, save and invest; if that led to an increase in the supply of goods and services, then the impact would be anti-inflationary.

Mainstream economists also argued that the cost of bringing down inflation, even a little bit, would be extraordinarily high. In a May 1978 paper, Brookings Institution economist Arthur Okun calculated that bringing the inflation rate down by just one percentage point would cost 10 percent of a year’s gross national product.

If Keynesian theory was correct, the 1981 Reagan tax cut, which reduced revenue by close to 3 percent of GDP per year, should have been massively inflationary. But in fact, inflation dropped like a rock, from 12.5 percent in 1980 to 8.9 percent in 1981 and 3.8 percent in 1982, where it basically stayed for the rest of the 1980s.

Of course, the Federal Reserve’s tight money policy did the heavy lifting on reducing inflation. But if Okun’s estimate had been even remotely correct, we should have gone through another Great Depression. Although the 1981-82 recession was painful, it was brief and not very deep. Real GDP fell 1.9 percent in 1982 but bounced back nicely, rising 4.5 percent in 1983 and 7.2 percent in 1984.

Republicans like to say that massive growth followed the Reagan tax cut. But average real GDP growth during Reagan’s eight years in the White House was only slightly above the rate of the previous eight years: 3.4 percent per year vs. 2.9 percent. The average unemployment rate was actually higher under Reagan than it was during the previous eight years: 7.5 percent vs. 6.6 percent.

Liberals argue that the real economic effects of Reagan’s policies show that they failed. However, I believe that these critics overlook the enormous importance of breaking the back of inflation at a relatively small economic cost — certainly far less than any economist would have thought possible in 1981. Reagan’s results should be measured against the (incorrect) expectation that a far more severe economic downturn would be needed to reduce inflation. On that basis, his policies were overwhelmingly successful.

When comparing Reagan’s policies with Republican proposals today, several things stand out. Inflation is low now. We are not looking at “bracket creep” or sharply rising taxes, as we were in the late 1970s. The top income tax rate is 35 percent, half the rate Reagan inherited. And federal revenue is at a 60-year low of about 15 percent of GDP, compared with a post-World War II average of about 18.5 percent.

These differences are essential to understanding why Reagan’s policies worked when they did — and why they are not appropriate today.

All of the evidence tells us that the economy’s fundamental problem today is not on the supply side but the demand side. According to a recent study by Credit Suisse, two-thirds of the difference in growth at this point in the business cycle, compared with previous cycles, is due to slower consumer spending. And low inflation — as well as widespread unemployment, vast stocks of unsold houses, empty factories and other indicators — tells us that money is tight, not loose, as was the case in the late 1970s.

“Low interest rates are generally a sign that money has been tight,” economist Milton Friedman wrote in 1997. Yet, absurdly, Republicans continually berate the Federal Reserve for being too easy; some even insist, insanely, that the United States should return to the gold standard, even though it was a key cause of the Great Depression.

Because inflation and interest rates are low, Fed policy is constrained today in ways it was not in the early 1980s. Back then, the Fed could bring down the federal funds rate to a little less than the inflation rate and create negative real rates, thus stimulating borrowing, investment and consumption. It can’t do that now because it can’t reduce market interest rates below zero.

Economic conditions are entirely different today than they were in Reagan’s era, and different conditions demand different policies. Those who say otherwise are simply engaging in cookie-cutter economics — proposing whatever was popular and seemed to work once, without regard to changing circumstances.

Bruce Bartlett was a domestic policy adviser to President Ronald Reagan and a Treasury official during the George H.W. Bush administration. His latest book is “The Benefit and the Burden: Tax Reform — Why We Need It and What It Will Take.”

Read more from Outlook :

Five myths about Ronald Reagan

Five myths about the debt ceiling

Friend us on Facebook and follow us on Twitter.