Economic growth in the advanced economies seems stalled. This summer the IMF projected increases in GDP in these economies of 1.8% for both 2016 and 2017. This included growth of 2.2% this year in the U.S. and 2.5% in 2017, 1.6% and 1.4% in the Eurozone in 2016 and 2017 respectively, and 0.3% and 0.1% in Japan. U.S. Treasury Secretary Jack Lew has called on the Group of 20 countries to use all available tools to raise growth, as has the IMF’s Managing Director Christine Lagarde. So why aren’t the G20 governments doing more?

The use of discretionary fiscal policy as a stimulus seems to be jammed, despite renewed interest in its effectiveness by macroeconomists such as Christopher Sims of Princeton University. While the U.S. presidential candidates talk about spending on much-needed infrastructure, there is little chance that a Republican-controlled House of Representatives would go along. In Europe, Germany’s fiscal surplus gives it the ability to increase spending that would benefit its neighbors, but it shows no interest in doing so (see Brad Setser and Paul Krugman). And the IMF does not seem to be following its own policy guidelines in its advice to individual governments.

One of the traditional concerns raised by fiscal deficits rests on their impact on the private spending that will be crowded out by the subsequent rise in interest rates. But this is not a relevant problem in a world of negative interest rates in many advanced economies and very low rates in the U.S. The increase in sovereign debt payments should be more than offset by the increase in economic activity that will be reinforced by the effect of spending on infrastructure on future growth.

On the other hand, there has been no hesitation by monetary policymakers in responding to economic conditions. They initially reacted to the global financial crisis by cutting policy rates and providing liquidity to banks. When the ensuing recovery proved to be weak, they undertook large-scale purchases of assets, known in the U.S. as “quantitative easing,” to bring down long-term rates that are relevant for business loans and mortgages.The asset purchases of the central banks led to massive expansions of their balance sheets on a scale never seen before. The Federal Reserve’s assets, for example, rose from about $900 billion in 2007 to $4.4 trillion this summer. Similarly, the Bank of Japan holds assets worth about $4.5 trillion, while the European Central Bank owns $3.5 trillion of assets.

The interventions of the central banks were successful in bringing down interest rates. They also elevated the prices of financial assets, including stock prices. But their impact on real economic activity seems to be stunted. While the expansion in the U.S. has lowered the unemployment rate to 4.9%, the inflation rate utilized by the Federal Reserve continues to fall below the target 2%. Investment spending is weaker than desired, despite the low interest rates. Indeed, many firms have sufficient cash to finance capital expenditures, but prefer to hold it back. The situations in Europe and Japan are bleaker. Investment in the Eurozone, where the unemployment rate is 10.1%., remains below its pre-crisis peak. Japan also sees weak investment that contributes to its stagnant position.

If lower interest rates do not stimulate domestic demand, there is an alternative channel of transmission: the exchange rate, which can improve the trade balance through expenditure switching. But there are several disturbing aspects of a dependence on a currency depreciation to increase output (see also here). First, there is an adverse impact on domestic firms with liabilities denominated in a foreign currency, as the cost of servicing and repaying that debt rises. Second, expansionary monetary policy does not always have the expected impact on the exchange rate. The Japanese yen appreciated last spring despite the central bank’s acceptance of negative interest rates to spur spending. Third, a successful depreciation requires the willingness of some other nation to accept an appreciation of its currency. The U.S. seems to have accepted that role, but Mohammed A. El-Erian has pointed out, U.S. firms are concerned “…about the impact of a stronger dollar on their earnings…” He also points to “…declining inward tourism and a deteriorating trade balance…” Under these circumstances, the willingness of the U.S. government to continue to accept an appreciating dollar is not guaranteed.

There is one other consequence of advanced economies pushing down their interest rates: increased capital flows to emerging market economies. Foreign investors, who had pulled out of bond markets in these countries for much of the last three years, have now reversed course. The inflows may help out those countries that face adverse economic conditions. But if/when the Federal Reserve resumes raising its policy rate, the attraction of these markets may pall.

The search for an effective macro policy tool, therefore, is constrained by political considerations as much as the paucity of options. But there is another factor: is it possible to return to pre-2008 economic growth rates? Harvard’s Larry Summers points out that those rates were based on an unsustainable housing bubble. He believes that private spending will not return us to full-employment, and urges the Fed to keep interest rates low and the government to engage in debt-financed investments in infrastructure projects. Ken Rogoff (also of Harvard), on the other hand, believes that we are suffering the downside of a debt supercycle. Joseph Stiglitz of Columbia University blames deficient aggregate demand in part on income inequality.

The one common theme that emerges from these different analyses is that there is no “quick fix” that will restore the advanced economies to some economic Eden. Structural and other forces are acting as headwinds to slow growth. But voters are not interested in long-run analyses, and many will turn to those who claim that they have solutions, no matter how potentially disastrous those are.