Canada's standard of living slid five spots to ninth among the world's 17 top industrialized nations in the past two decades, according to a report from the Conference Board of Canada.

The country used to be fourth in terms of living standards but has slipped five spots since 1990, said the Ottawa-based think tank on Monday.

The findings were published in the board's new overall scorecard on the Canadian economy.

The conference board defined 'standard of living' as income per capita.

The organization said Canada's average income per capita stood at $31,175 US in 2006, nearly $8,500 less than the world leader Norway.

Canada also trails the United States in this measure. Canada's per-person income is approximately $6,400 less than the U.S. average income, a gap that has doubled between 1984 and 2006.

"Lower labour productivity accounts for the largest component of the income gap between Canada and the United States," the conference board said.

Productivity measures how much each worker makes. In Canada, the measure has trailed American productivity growth for at least a decade.

The conference board has long argued that Canada's tax and regulatory regimes are too restrictive and drag on productivity.

"Canada needs to boost investment in resource sectors by eliminating the capital tax on businesses and removing remaining internal trade barriers, such as restrictions on interprovincial log trade in the forest sector," said board president and chief executive officer Anne Golden in a 2005 newspaper editorial.

Other analysts agreed with the concern over Canada's lagging productivity but not the board's solutions.

Jim Stanford, chief economist with the Canadian Auto Workers, said Canada's high dollar and the country's concentration in energy industries are bigger threats to national productivity than the tax regime.

"The very poor performance of Canadian productivity during the last three years reflects the structural effects of Canada's energy specialization as a producer and exporter of natural resources," Stanford wrote in a recent study for the Canadian Centre for Policy Alternatives.

Overall showing

Overall, the Conference Board gave Canada a "B" for economic performance, the 11th out of 17 countries.

Ireland leads the world in terms of economic performance. In addition, four of the top six economic performers hail from Scandinavian countries.

Canada ranks ahead of Austria, Australia, Japan, France, Italy and Germany in economic performance, the conference board said.

Of the major categories in the study, Canada received its worst marks in "innovation," where the country scored a "D."