The religion question in the census seems to be getting far more than its fair share of attention. This year will see campaigns to write "mind your own" in response, to state your religion as "Dudeist" (followers of the Dude from The Big Lebowski) or pagan, and of course the Jedis are still after your support. The biggest campaign, however, comes from the British Humanist Association (BHA), who want you to say that you have no religion, in line with similar campaigns in Ireland, Australia and elsewhere.

In Monday's response to the question Andrew Copson from the BHA argued that if you are not religious, you should say so. And, of course, he is right. Mouse offers his support to all of these campaigns. If you are a Dudeist, pagan, atheist or a privacy advocate, then you should act as your conscience dictates, and accurately state your convictions.

Copson's main concern is that people who aren't "proper" Christians may say that they are due to a vague cultural association with Christianity, rather than any real belief. However, let's not quite write off the "weak cultural affiliation" that Copson is campaigning against. If you think you are a Christian, don't let him tell you that you are not.

There are generally three aspects to religiosity measured by surveys and statistics: religious identity, religious belief and religious behaviour. These three dynamics operate independently – some believe with all their heart but do not go to church, whilst others go to church every week and don't believe a word of it. Still others consider they belong to a religious group but are not sure what they believe. The census question does not try to untangle this knot, but aims to measure religious identity.

Far from being "ridiculous" and "aberrant", as Copson claims, the 2001 census result on religion was very much in line with the ONS's yearly Integrated Household Survey. Last year, yet again, it showed that over 70% consider themselves Christian when asked the question "what is your religion, even if you are not currently practising". This question is deliberately designed to measure religious affiliation, and not belief or practice. Of course, measures of the other factors do show different results.

However, while Mouse supports the general call to fill in the census form accurately, he does take issue with the claim that "major public policy developments have occurred and resources allocated on the back of these erroneous numbers". The BHA campaign website provides a long list of policies which have been linked to the 2001 census question, from the growth of faith schools to the presence of bishops in the House of Lords.

Yet the underlying evidence provided to substantiate a direct link is rather flimsy. It includes quotes from non-policy reference documents, such as the Faith in the System education report and verbal comments from bishops in the House of Lords, which clearly were not part of the policymaking process. Both faith schools and Lords Spiritual, for example, existed long before the religion question was asked in the 2001 census and to draw a causal link between the two is spurious.

So if you are going to say that you have no religion, Mouse suggests you do so because it is true, not because you think that will change government policy.