The Federal Reserve is close to embarking on another round of monetary stimulus next week, against the backdrop of a weak economy and low inflation—and despite doubts about the wisdom and efficacy of the policy among economists and some of the Fed’s own decision makers. The central bank is likely to unveil a program of U.S. Treasury bond purchases worth a few hundred billion dollars over several months, a measured approach in contrast to purchases of nearly $2 trillion it unveiled during the financial crisis. The announcement is expected to be made at the conclusion of a two-day meeting of its policy-making committee next Wednesday. The Fed’s aim is to drive up the prices of long-term bonds, which in turn would push down long-term interest rates. It hopes that would spur more investment and spending and liven up the recovery. But officials want to avoid the “shock and awe” style used during the crisis in favor of an approach that allows them to adjust their policy, and possibly add to their purchases, over time as the recovery unfolds. Fed Chairman Ben Bernanke’s push to restart the bond-buying program—a form of monetary stimulus known as quantitative easing—has been greeted with deep skepticism among some of his colleagues.