(Adds detail from research paper, context)
LONDON, Oct 19 (Reuters) - Purchases of trillions of dollars of government debt by central banks globally have boosted economic growth, at least temporarily, Bank of England chief economist Andrew Haldane said on Wednesday.
His conclusion in a research paper came two weeks after British Prime Minister Theresa May's criticism of "some bad side effects" of the bond purchases known as quantitative easing (QE).
The paper - which did not address the outlook for BoE rates - found "reasonably strong evidence of QE having had a material impact on financial markets, generating a significant loosening in credit conditions".
"There is also evidence of QE having served to boost temporarily output and prices, in a way not associated with other central bank balance sheet expansions," Haldane added.
He said QE by other central banks, especially by the U.S. Federal Reserve, had "strong positive international spillover effects".
While criticism of QE is common among U.S. and German politicians, May's remarks about the policy's adverse effects on the distribution of wealth were the first from a senior serving member of Britain's government.
May's aides and her finance minister Philip Hammond have since rebuffed suggestions that she was trying to influence the BoE's policy decisions. The central bank's inflation-fighting mandate is set by the government, but it has operational independence in how it reaches this goal.
Earlier on Wednesday, Hammond said QE had helped create millions of jobs in Britain, benefiting many people beyond the minority whose assets were boosted by BoE bond-buying. (Reporting by William Schomberg and David Milliken; editing by Mark Heinrich)