The first program instituted by the Government of Quebec was for $8,000 in a single year. It was a refundable tax credit. The government tabled an amendment to allow for some withholding, so that young people would have a better opportunity to live in a designated region. This is why it's spread over several years now. However, I think that someone who lives in a given region for a number of years, buys a house there, forges some links and makes friends has a much greater chance of staying there over the longer term.
On February 27th, 2008. See this statement in context.