Yellen said the pool of available workers has been growing slowly "and immigration has been an important source of labour force growth". Photograph: (AFP)
With the US population ageing, flow of foreign workers has been an important factor in keeping the economy expanding: Yellen
Curbing immigration, as US President Donald Trump appears intent on doing, could slow already sluggish US economic growth, Federal Reserve Chair Janet Yellen cautioned Tuesday.
With the US population ageing, the flow of new workers from abroad has been an important factor in keeping the economy expanding, Yellen said in her first testimony before Congress since Trump took office last month.
While she declined to comment on specific immigration policies, Yellen said the pool of available workers has been growing slowly "and immigration has been an important source of labor force growth".
"So slowing the pace of immigration probably would slow the growth rate of the economy," she added.
She called the 1.9 percent US growth rate last year "disappointing," and emphasized that productivity -- the ability of workers to produce more goods and services -- has lagged.
"We have an aging population and labor force growth is relatively slow, and productivity growth in recent years has been depressingly slow," which keeps economic growth low, Yellen said.
Trump's early days in office have been marked by controversy over an order barring entry to nationals from seven Muslim-majority countries, since blocked by the courts, as well as nationwide raids to scoop up and deport illegal immigrants with criminal records.
Yellen, however, said specific immigration policies are "for Congress and the administration to decide".