In the past two years, the price of oil has been cut in half while Calgary's unemployment rate has nearly doubled.

Wages are down. Consumer spending is down. Real estate sales are down.

And yet, real estate prices have barely moved.

While far fewer homes are changing hands, the average sale price in the city has been $479,464 so far in 2016. That's a decline of just 0.5 per cent from the average price in 2014, according to Calgary Real Estate Board data.

So what's going on?

Several things, according to analysts. But one factor, in particular, was identified in an internal Finance Department memo obtained by CBC News.

It found the initial impact of Alberta's economic downturn has been blunted because tens of thousands of Canadians who worked in the province but paid taxes in other jurisdictions and didn't engage in local real estate markets have left after being laid off.

"Their departure is resulting in a lower number of unemployed in Alberta than would otherwise be the case, minimizing any downward pressure on the housing market (they are likely not Alberta homeowners — although the rental market may be affected)," reads the memo, which was obtained under an access to information request.

"The departure of these itinerant workers should benefit the Alberta economy by dispersing the negative impacts of the shock to other provinces," it adds.

Itinerant worker boom, then bust

Alberta has long been a destination for workers from other provinces, but the Finance Department examination highlights the scale to which their ranks had grown just prior to the crash in oil prices and the degree to which they appear to have been impacted, in particular, by recent layoffs in the fossil fuel industry.

The itinerant workforce is estimated to have surpassed 150,000 people in 2013 — more than double what it was a decade earlier.

An internal Finance Department memo says 'it is likely that between 70,000 and 80,000 of the total population of 154,000 interprovincial workers in Alberta were employed in the construction and oil and gas sectors and other sectors that support oil and gas production.' (Canadian Press)

Of those, between 70,000 and 80,000 are estimated to have been involved in oil and gas and related sectors, such as construction, that support fossil fuel production.

But in a span of 10 months following the oil crash, roughly 56,000 workers appear to have left Alberta, which the memo attributes largely to itinerant workers going home.

More immediate impact on rental market

Don Campbell, a senior analyst with the Real Estate Investment Network, said Alberta's itinerant worker situation is one "that we've been paying very close attention to," given its impacts on the rental market in particular.

Don Campbell, a senior analyst with the Real Estate Investment Network, says Calgary's relatively high rental market has provided some stability to housing prices. 3:42

"We know that itinerant workers generally don't participate in the actual real estate market," he said.

Alberta's itinerant workers are particularly unusual in their housing use, Campbell said, in that many live at work camps for long stints each month. When not working, they either fly home to their provinces of origin or return to barely used apartments rented in Alberta and shared among several people.

"In the regular rental market, you would not have that," he said.

Still, the departure of so many people has had an impact on vacancy rates, which Campbell said was first seen in places like Grande Prairie, Slave Lake and Fort McMurray, but has since spread to larger centres.

Calgary vacancy rate

Calgary saw a huge spike in unoccupied homes, according to the latest civic census, which pegged the number of vacant units at 21,000 in April, up 8,300 from the year before.

That pushed the vacancy rate to 4.3 per cent, a level not seen in more than a decade.

This was largely driven by the first negative net migration the city has seen since 2010, with some 6,500 more people leaving Calgary than moving here.

At the same time, though, the number of owner-occupied homes actually grew by 3,700 to surpass 323,000, suggesting many of the people moving away from the city were leaving rental units, not homes they owned.

It's unclear how many itinerant workers have left Calgary, specifically, but the departure of so many across the province does have other benefits for those who are still working and looking for work in Alberta, according to Ron Kneebone, an economics professor at the University of Calgary's School of Public Policy,

Ron Kneebone, a professor of economics at the University of Calgary's School of Public Policy. (Robson Fletcher/CBC)

"During Alberta's boom, Alberta companies were paying $200 to $300 a week more than what people were earning in other provinces," he said.

"Now that the boom's over, they're moving back to other provinces, and that's a benefit to the workers that stay here. Their wages will not fall by as much, because these people are now leaving."

Delayed effect on house prices?

While all this may have helped Calgary's real estate market steer clear of the plunging indicators seen elsewhere in Alberta's economy, Campbell doesn't believe it can last forever.

"It always takes a couple of years before the reality sets in," he said.

"But where we've been blessed in Calgary is in that it has not been a couple of years before the turnaround occurs, at least since the 1980s."

But he said the city is finding itself "deep into that second year now" and into relatively uncharted waters for those who don't recall the longer downturns of the more distant past.

A house for sale in Calgary. (Robson Fletcher/CBC)

"The negative momentum we'll start to see increasing over the next six months or a year, as confidence starts to wane that this is not one of those typical two-year blips," Campbell said.

"That's when you start to see the more dramatic price drops."

That's also what Edmonton-based securities analyst Hilliard MacBeth expects, particularly as the availability and affordability of rental housing grows.

"When there's lots of rental available at really cheap prices and we're not in a boom anymore, it'll really have an impact on being able to sell homes," he said.

"There's no way that these changes don't start showing up in a big way in the housing market in Alberta."