The think-tank Resolution Foundation said that represented the sharpest fall anywhere in the UK.
It said Northern Ireland has been overtaken by the North East, Wales and Yorkshire and the Humber and now has the lowest household incomes in the UK.
It said official data on incomes was either flawed or out of date.
The think-tank said typical household incomes in Northern Ireland were £21,794 on the eve of the economic downturn.
Northern Ireland then experienced the sharpest fall in living standards of anywhere in the UK, with typical incomes falling by 6.7% (or £1,470 a year) between 2007-08 and 2011-12.
Living standards have recovered steadily since then but were still £864 below their pre-downturn level in 2014., according to the study.
Further increases are expected this year.
It said the weak performance of Northern Ireland was due in part to it having a relatively sluggish jobs recovery compared to the rest of the UK.
Its current employment rate is still 2.1% lower than in early 2008.
Northern Ireland also suffered the biggest real pay squeeze of anywhere in the UK, with typical hourly wages falling by 13.4% between 2009 and 2014, compared to a UK figure of 9.3%.
The Resolution Foundation has also said there was a big generational divide in experiences of the downturn.
Typical incomes among pensioner households were 9.4% above their pre-downturn level last year, while working age households were still 4.6% down.
Laura Gardiner, of the foundation, said: "Northern Ireland experienced the biggest fall in living standards of anywhere in the UK, with typical incomes falling by almost £1,500 between 2008 and 2012.
"This is largely down to the pay squeeze workers faced. Typical incomes have recovered since then but there is a long way to go before they return to pre-downturn levels.
"There are also considerable generational differences behind this headline fall in living standards, with pensioner households likely to have fared far better than those of working age.
"This makes it hard to talk about living standards in a way that resonates with people's experiences across Northern Ireland."
Typical household incomes in Northern Ireland were 4% - or £860 - below their pre-economic downturn level last year, according to a new study.