OTTAWA - While Canada debates the merits of a compulsory long-form census, its neighbours to the south have already decided a national voluntary survey doesn't work.

At the behest of Congress, The U.S. Census Bureau conducted an experiment in 2003 using its compulsory American Community Survey to see what would happen if some people were given the choice of filling it out.

The result? The data was degraded so much, fixing it would be too expensive. The idea was quickly abandoned.

"It showed that for our survey, it would have been a lot more money to do the survey, and so Congress took that into account and decided they would keep it as a mandatory survey," said David Raglin, a senior official with the U.S. Census Bureau.

The American Community Survey or ACS goes out to three million households a year, and produces data every five years. The U.S. replaced the traditional long-form census with the compulsory ACS after 2000, because it felt the long census competed with the short census.

The survey also produces reliable data more quickly than the old long census, and uses professional interviewers instead of temporary staff hired every 10 years.

Prime Minister Stephen Harper's cabinet decided this summer to eliminate the compulsory long census next year, and replace it with a voluntary survey. Officials have said the change is a response to Canadians who find the long census intrusive and coercive, given there is the threat of fines or jail times for not filling it out.

A wide cross-section of Canadian organizations and governments have decried the change -- including the Canadian Jewish Congress, the Federation of Francophone and Acadian Communities, the Quebec government, the Inuit Tapiriit Kanatami, and the Canadian Medical Association Journal.

On Monday, a diverse coalition of groups that included the Toronto Board of Trade, the Canadian Nurses Association and the Canadian Labour Congress requested a meeting with Harper about the census change. The heads of six Canadian think-tanks, including the Conference Board of Canada, the Institute for Research on Public Policy and the Canada West Foundation, sent Harper a letter of opposition.

"We're not there to please all special interest groups, we're there for the silent majority of Canadians," Conservative MP Maxime Bernier told The Canadian Press on Sunday.

"I'm sure that the big majority of Canadians understand that, and will agree with our decisions."

Bernier said he had received 1,000 messages at the time from Canadians upset with the 2006 census. On Monday, he said on his blog that "these messages were obviously not filed for future use by my staff and were deleted."

The House of Commons industry committee was scheduled to meet Tuesday to discuss another topic, but all four federal parties have said they want to raise the census issue with Industry Minister Tony Clement.

Statistics Canada has said it can't quite predict what the impact on the data will be, but the U.S. experiment might be instructive.

When a percentage of Americans were given the choice of filling out the national survey, the mail-back response rate dropped by a third.

And as some in Canada have warned about the impact on the long census, the response rates among certain groups became too low for reliable information. For example, the proportion of completed surveys dropped to about 20 per cent for Blacks and Hispanics.

"The use of voluntary methods had a negative impact on traditionally low response areas, that will compromise our ability to produce reliable data for these areas and for small population groups such as Blacks, Hispanics, Asians, American Indians, and Alaska Natives," says the census bureau's 2004 report.

Ultimately, the bureau found that if it wanted to maintain the reliability of the data, it had to send the survey to more homes, at a cost they couldn't stomach -- $59.2 million more. In Canada, the government has committed to spending an additional $30 million, and mailing out the survey to 60 per cent more homes.

Former chief statistician Ivan Fellegi told The Canadian Press that the government would be better off completely doing away with the long form, rather than try to salvage data with a more expensive voluntary process.

The current chief statistician, Munir Sheikh, has refused to do interviews with the news media. His office sent an internal email, obtained by the Hill Times weekly newspaper, to staff Monday announcing a departmental town hall meeting later this week.

A vigorous debate has gone on in the United States over the decennial short-form census. Activists with the Republican-rooted Tea Party movement, and personalities such as radio and TV host Glenn Beck and Texas Congressman Ron Paul, have railed against the process as state intrusion into their lives.

On Beck's radio show last year, he said the question on race in the census was designed to deliver more government dollars to minorities. He called it an attempt to "increase slavery."

"Your dependence on the master in Washington," Beck said. "No way, don't answer that question."