Census day is here and who knew a government questionnaire and the return of its mandatory longer version could inspire such goodwill among Canadians?

But at the risk of putting a damper on the occasion, some statisticians say the census's days, at least in its traditional form, could be numbered.

That goodwill could be the silver lining to the Conservative government's 2010 decision to get rid of the mandatory long-form census. Justin Trudeau's Liberal government overturned that move in one of its first acts in office.

Suzanne Crone, a writer living in Uxbridge, Ont., was excited to complete her census online.

"I was just thrilled that it was coming back and we were back to the Information Age," Crone told CBC News.

She completed the short-form census, found the questions clear and says she understands how the information would be useful for running the country. If census data becomes unreliable, "it's governing by assumption and just taking shots in the dark," she says.

Census expert Doug Norris says Crone's census sentiments are widespread in Canada this time around. The debate about cancelling the mandatory long-form census led to a much better public understanding about its importance, he says.

"And once people realize that this stuff is really useful and can perhaps improve their own lives, they are much more willing to take part, and to take the time and fill out the census," says Norris, the chief demographer for Environics Analytics who spent nearly 30 years at Statistics Canada.

Whatever day you complete the census, Statistics Canada wants the information as of May 10, 2016. (Statistics Canada)

Other census approaches

After replacing the mandatory long-form census with the voluntary National Household Survey in 2011, which 30 per cent of Canadians did not complete, Statistics Canada also undertook a review to determine whether the census is still the best way to gather that data.

Especially given the time constraints of making any major change, the agency decided to stick with its traditional approach for 2016. It did note, however, that while most countries use a model similar to Canada's, "there is a shift internationally towards other census approaches."

The report says among the member countries of the UN Economic Commission for Europe, which includes Canada, 10 of 37 that used a traditional census the previous time moved to a new approach in their latest census.

If you try to complete the census online and get a message to try again because of the high volume of requests, you can request the printed forms. (Peter Zimonjic/ CBC)

In October, New Zealand's government decided to move towards a census based primarily on its administrative data, such as births, deaths and immigration, supplemented by mandatory, large-sample household surveys every five years.

The U.K., which conducts a traditional census every ten years, is also considering a change and has established a "Census Transformation Programme."

At least 20 of the 56 UNECE countries use a population register system to compile their census-type data. That register is linked with an administrative register for building/dwelling data and to other registers and other data sources to complete the demographic picture.

The four Nordic countries established central population registers in the 1960s, which evolved from national and local registers dating back centuries. Registers for businesses, dwellings, education, and employment followed.

The U.S. and France now use continuous data collection, supplemented with administrative data "to ease respondent burden and/or improve data quality," as StatsCan describes it.

Since 2005, the U.S. has relied on the American Community Survey rather than a long-form census. The questions are similar, with a sample size of about 300,000 annually. In 2013, an effort by Tea Party Republicans in Congress to defund the survey was defeated.

Canada's census future

For Canada's census, Doug Norris sees a future similar to the U.S. model, which uses a small mandatory census and the American Community Survey. (Environics Analytics)

For Canada's census, Norris sees a future similar to the U.S. model. For him, a small mandatory census and then sampling different topics at different times looks attractive.

He says this would mean a change from a portrait of Canada at a point in time to averaging over time, but "in reality many of the factors that the census measures don't change very much so if you have an average over two years that's good enough for most applications."

Norris describes the traditional census as very expensive and "a burden of sorts on the public," at least the one in four who get the mandatory long form.

For Canadians who only need to complete the mandatory short form, it can become a bit of a burden if you pause for more than 20 minutes while answering the questions online because it will time out and make you start over.

Pausing for more than 20 minutes while answering the short-form census online leads to the session timing out and then starting over from the beginning. (Statistics Canada)

Long form too long

Statistician Philip Cross, a research fellow at the C.D. Howe Institute, says the Liberals made the correct decision reinstating the mandatory long-form census, but warns the survey is too long and that may lead to less reliability.

"I don't really think that it's intrusive that bugged people, I think it was just the fact that it was so long," he says of the Conservative government's rationale for scrapping the mandatory long form.

The former chief economic analyst for Statistics Canada says for past long forms, the response rate was very high for the first 10 to 20 questions, "then people got bored or bogged down" with hard questions at the end and the response rates dropped way down.

He says the long form got out of control and the census questions should be limited to what the government needs to know. Surveys or other data sources should be used to collect the rest.

Cross says when he left in 2012, Statistics Canada "was aware that the future is not censuses" and the agency would need to find other ways to collect the data.

Income data 'not believable'

He says census income data, for example, is unreliable. It says there's been no income growth in this country since 1981, but he doesn't believe that. He says income tax data and disposable income data from the National Accounts system on economic activity tell a different story.

The income questions were left out of the long form this year and Statistics Canada will access Canada Revenue Agency data instead.

Cross would also like to see questions about what we spend on utilities dropped from the long-form census because the information is unreliable and too much of a burden for people to accurately estimate.

"Everybody likes census data because it was cheap for them," Cross says, but it isn't cheap for Statistics Canada. The bill for the 2016 census is expected to ring in at $715 million.

"Proponents of census frame the issue as census is the ultimate in evidence-based policymaking," he says, but they advance very little evidence. "What is the evidence that [the National Household Survey] hampered policymaking? What is the evidence that having a census every five years instead of every 10 leads to better policy?"

For Doug Norris, the census questions change too slowly. He points to the question on the short form about a person's sex as an example. The choices are male or female, prompting criticism from transgender groups and others. He expects a change to that question in the next census.

And Norris says the census misses three to four per cent of the population, with ten per cent of young people missed in the last census.

"The census is the best we've got now but it's by no means perfect and keep that in mind when looking at alternatives."