OTTAWA — Alarm about the government's decision to kill off the long-form census has spilled over to the business community.

Both the Canadian and Toronto associations of business economists are drafting letters to Industry Minister Tony Clement to protest cabinet's decision to replace the mandatory, long census form with a voluntary survey next year.

Board members say the census is the most important piece of information they use, both for research on public policy and also to help companies reach key decisions about marketing and expansion.

The government has said that in 2011, the census exercise will no longer include the mandatory long questionnaire that used to go to a fifth of respondents.

A voluntary survey will be issued instead, asking about ethnicity, income and education, but critics say the data will be biased and unreliable.