Reforms to boost pension coverage will only produce a "small" increase in retirement saving among lower earners, the Institute for Fiscal Studies claims.
The think-tank said the shift to automatic enrolment and increased requirements on employers to make contributions should boost pensions for existing savers but warned it would have little effect on those not currently offered the chance to join a workplace scheme.
It said default pension contributions from the 4.7 million employees not offered the chance to join an employer pension in 2005 would have totaled £4.2bn.
But it said many individuals would accumulate relatively small amounts - noting that, over the five years from 2001 to 2005, half of these 4.7 million employees would have made total contributions of less than £2170.
Institute for Fiscal Studies senior research economist, and one of the authors of the report, Matthew Wakefield said: "In 2005 half of employees not contributing to a private pension earned less than 14,000, and more than half had no net savings.
"Getting such individuals into pension saving might be seen as a success of the policy, but any increase in pension saving is, at least in absolute terms, likely to be small."
He added: "While many of these individuals have little scope to finance new pension saving by reshuffling existing assets, some could pay down existing debts less quickly, which would still mean that new pension saving was not new saving overall."
The Association of British Insurers said it was vital the new system of personal accounts was implemented properly
It added: "The report shows that the lowest earners will dip in and out of pension saving, so such people must have more than just the proposed 30 days in which to decide whether they should remain auto-enrolled.
"The government could also give the whole system a kick-start by allowing willing employers to automatically enrol their employees into existing good workplace pensions as soon as possible."Professional Pensions
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