More from Edmund Phelps. In this Project Syndicate commentary, he cautions that tax cuts do not affect unemployment rates in the long-run and therefore, contrary to the claims of many supply-side advocates, tax cuts will not permanently reduce unemployment rates in Europe:
The false hopes of tax cuts, by By Edmund Phelps, Project Syndicate: There is a movement in medicine to require that applications for licenses to sell a new drug be "evidence-based." By contrast, trained economists view their discipline as having already achieved this scientific standard. After all, they express their ideas with mathematics and arrive at quantitative estimates of implied relationships from empirical data.
But economics is not evidence-based in selecting its theoretical paradigms. Economic policy initiatives are often taken without all the empirical pretesting that could have been done.
A notorious example is postwar macroeconomic policymaking under the ... neo-Keynesians... Like the radicals, the neo-Keynesians did not engage their challengers with empirical testing. The efficacy of high demand was a matter of faith. Yet events in the 1970s put that faith to a cruel test. When supply shocks hit the U.S. economy, the neo-Keynesians' response was to pour on more demand, believing it would revive employment. There was little recovery -- only faster inflation.
The current era offers a parallel. Although policy has since shifted to reflect supply-side economics and real business-cycle theory, the new paradigm builders and promoters display the same antipathy to checking data for serious error. ...
[S]upply-siders [have] jumped to the daring conclusion that a permanent cut in tax rates on labor would encourage more work permanently -- with no diminution of effectiveness.
Larry Summers and I both doubted that this could be generally true. If every increase in the after-tax wage rate gave a permanent boost to the amount of labor supplied, we reasoned, steeply rising after-tax wages since the mid-19th century would have brought an extraordinary increase in the length of the workweek and in retirement ages. But both have fallen, and in continental Europe unemployment is higher.
In my view, this core tenet of supply-side economics rests on a simple blunder. What matters for the amount of labor supplied is the after-tax wage rate relative to income from wealth. While after-tax wage rates soared for more than a century, the wealth and the income it brought grew just as fast.
To be sure, if tax rates were decreased permanently this year, there would initially be a strongly positive effect on labor supplied. But there would also be a positive effect on saving and thus on wealth next year and beyond. In the long run, wealth could tend to increase in the same proportion as after-tax wages. The effect on work would vanish.
We must proceed cautiously. In standard analyses, the tax cut brings a reduction in government purchases of goods and services, like defense. But a tax cut could instead contract the welfare state -- social assistance and insurance, which constitute social wealth. In that case, the tax cut, while gradually increasing private wealth, would decrease social wealth. The issue is an empirical one.
Research I did with Gylfi Zoega a decade ago confirmed that cuts in taxes on labor boost employment in the short run. But what about the long run? Do large long-run effects of tax rates show up in international differences in employment?
In 1998 we examined data ... for a correlation between national unemployment rates in the mid-1990s and tax rates on labor. We found none. In 2004, we looked at labor-force participation rates and again at unemployment. Still no correlation. ...
Neoliberals are now telling continental Europe that tax cuts on labor can dissolve high unemployment. But the effectiveness of such tax cuts would be largely, if not wholly, transitory -- especially if the welfare state was spared. In two decades' time, high unemployment would creep back.
The false hopes raised by cutting taxes would have diverted policymakers away from fundamental reforms that are necessary if the Continent is to achieve the dynamism on which high rates of innovation, abundant job creation, and world-class productivity depend.