Alberta has seen a dramatic plunge in child poverty rates, driven largely by provincial and federal benefits targeted at low-income families, according to a University of Calgary economist.

Figures released by Statistics Canada on Tuesday show Alberta's rate was cut in half between 2015 and 2017, falling from 10 per cent of children living in poverty to five per cent.

Economist Trevor Tombe says the decline is largely due to the Canada Child Benefit introduced by the federal Liberal government and the Alberta Child Benefit — a policy proposal introduced by former PC premier Jim Prentice and later enacted under Alberta's NDP government.

"So those two policies, combined, really dramatically increase the amount of child benefits that Alberta families receive, Tombe said.

The increase amounts to "a little more than double" what low-income families were receiving in 2014, Tombe said.

Huge variation across Canada in child poverty rates. Alberta has the lowest -- by far. The new "Alberta Child Benefit" and the CCB cut Alberta's child poverty rate in *half* since 2015. <a href="https://twitter.com/hashtag/cdnecon?src=hash&ref_src=twsrc%5Etfw">#cdnecon</a> <a href="https://twitter.com/hashtag/ableg?src=hash&ref_src=twsrc%5Etfw">#ableg</a> <a href="https://t.co/hRGilllCiq">pic.twitter.com/hRGilllCiq</a> —@trevortombe

Alberta already had the lowest child poverty rate in Canada prior to 2017, but also saw one of the most dramatic reductions in the past two years on record, thanks to what Tombe says is a large and targeted provincial benefit.

All provinces except Nova Scotia saw a decrease in child-poverty rates from 2015 to 2017.

The Alberta Child Benefit is available to all families with an annual income below $41,220, with the value depending on how many children they have.

A family with two children making $30,000 a year receives an additional $4,300 a year from the Canada Child Benefit and the Alberta Child Benefit, compared to previous amounts.

Not just child poverty

Tombe also points out that wages in Alberta are higher than elsewhere in Canada and have been for some time, meaning poverty rates — not just child poverty rates — were already low to start with.

Poverty in all categories was down in Alberta between 2015 and 2017. Figures for 2018, when the economic recovery was seen as starting to sputter, won't be available until next year.

Statistics Canada defines the poverty line in this case using a "market basket measure," essentially testing the ability of a family to afford the cost of a particular "basket" of goods and services.

Both that measure, and a different measure that compares income to the Canada-wide median — the "low-Income measure" (LIM) — show declines in the child poverty rate.

Nationally, the LIM rate for children dropped 1.9 percentage points between 2016 and 2017, falling to 12.1 per cent.