The August 2010 GDP numbers have been released (increase of 0.3% over July), so It's time once again to update my series of posts (most recent: 2010Q2) in which I try to take the GDP numbers from the first two months of a given quarter, mix them with the LFS numbers from the third month, and concoct a preliminary estimate for quarterly GDP growth. The BEA released theirs today (2.0%); here's mine: 1.5%.
It should be noted that that the result of this exercise is a probability distribution, not a single number. Its standard deviation is 0.5%, and the interquartile range is [1.2% , 1.9%].
Here is a table comparing the WCI 'backcasts' with the numbers produced by Statistics Canada:
Quarter WCI estimate First StatsCan
releaseLatest data 2009Q1 -6.9% -5.4% -7.0% 2009Q2 -3.4% -3.4% -2.8% 2009Q3 -0.4% 0.4% 0.9% 2009Q4 4.0% 5.0% 4.9% 2010Q1 5.5% 6.1% 5.8% 2010Q2 2.7% 2.0% 2.0% 2010Q3 1.5%
The slowdown we saw in 2010Q2 has continued through 2010Q3, and growth seems to be decelerating.
Worthwhile Canadian Initiative 
Did the Bank of Canada make a mistake by raising rates?
I don’t think so – GDP is now above its pre-recession peak. But I think it was right to pause when it did.
So far, it seems you underestimate when the housing market is improving, and overestimate when it is deteriorating. If the trend continues, we should come in around 1.3 or so….