Mike Mandel offers four candidates for the 'Economic Statistic of the Decade' over here, using these criteria:
First, we want to reward the economic statistic that best reflects the
decade (both the good and the bad). Second, we want to recognize the
economic statistic that turned in a surprising performance–that is,
back in 2000, if someone had shown you a graph of the statistic over
the next ten years, you would have said “no way”. Third, we want to
reward economic statistics that are reliable and accurate
representations of the actual economy.
If we restrict attention to the Canadian economy, there's really only one data series that satisfies these criteria. As I've explained repeatedly at and great length ([1], [2], [3], [4]), the story of the Canadian economy in the 2000's is the rapid increase, crash and partial recovery of commodity prices. Here is a graph of the Bank of Canada's weekly commodity price series, converted to Canadian dollars and scaled so that January 2000=100:
As documented elsewhere, the effects of the run-up in commodity prices include
- An increase in our terms of trade, which accounted for half the increase in GDI
- An accelerated shift of productive resources out of the manufacturing sector
When it comes to describing the Canadian economy over the past ten years, I can't think of another economic statistic that has anything near the explanatory power of commodity prices.
Worthwhile Canadian Initiative 
a) Broken link.
b) I think this is fundamentally bad news. Lower productivity, increased income maldistribution.
a) Fixed.
b) Huh?
If it looks like a bubble, smells like a bubble, bursts like a bubble …
Something related. Rick George of Suncor was recently designated by the G&M Nation Builder of the Decade for Business.
http://www.theglobeandmail.com/news/national/decade/decade-nation-builder/rick-george/article1416819/
Now, I can quibble with their choice (it seems to me a nation builder should spend more on R&D in Canada than Ralph Klein’s bar bill) but have a look at their stock price over the past decade (pick Suncor stock price history link – then ten yr tab)- and how it mirrors the graph above.
Boom boom, chuck-a-lucka
http://www.suncor.com/en/investor/439.aspx
The Teranet Housing Price Index probably meets the criteria pretty well, also.
Few would have believed the 2009 performance ahead of time – let alone the whole decade, it follows a similar pattern to the commodity index reflecting a generally strong Canadian economy over the decade, with a 2008 dropoff, 2009 recovery pattern, and the new index provides more reliable accurate information on the economy than the pre-existing indices did.
Two other possibilities. Trade share, which fell over the decade from the high growth during the 90s. Leveling off seemed more likely at the time, especially if you thought the growth in the 90s was fueled by the NAFTA. And the fall in labour productivity over the decade, again after strong growth in the 90s.
Neither is as dramatic as the commodity price index, I agree. But they are nonetheless somewhat surprising. And neither is purely exogenous to Canada.
And for the US, a suggestion would be a pseudo-statistic. The -5 or -6 percent Taylor rule interest rate, which I don’t think anyone would have come close to predicting. Related to this, the Fed balance sheet (either side) as so nicely tracked by Professor Hamilton at econbrowser.