I’ve just read a number of news articles on the possibility of the Australian Government saving a shit load of money (hundreds of millions) by cutting or changing the Australian Bureau of Statistics Census of Population and Housing. Now before you all start saying “hooray, I don’t have to complete that stupid survey form every 5 years”, there are a lot of really valuable reasons why the Australian Census should be excluded from any ‘economic rationalisation’ and why the survey is so important to the decisions that governments make every day that we really should have a “Save the ABS Census” campaign. Personally, as a policy analyst and past statistician, the very idea that you could contemplate diluting the very core of our evidence based decision making in this country is absolutely appalling. I could not do my job without its existence. I’m sick and tired of being already told, “we can’t afford to buy that data” to help me do my job better, but to not even having it available would be catastrophic.
So, why should the Census be unadulterated? Firstly, the Census collects information on every single individual person living in Australia, or does a very good job trying to. If we didn’t collect this information, governments would not know where to build a new school, create a new land subdivision, put in a new train, road, bus route etc. Besides allowing governments to make important planning and infrastructure decisions, it collects a wealth of information about ethnic and language groups, family and household formation, disability prevalence and carer support. Australia is constantly changing and the Census allows us to understand how those changes are being made and where. Without this information, not for profit groups, governments and businesses would not know how to meet the needs for services in our changing society. And don’t get me started on the lack of regional data available in this country. The Census is literally the only comprehensive and reliable avenue for anyone to access regional data. Losing the Census collection would not allow regional local governments to make cases for population change or funding allocations. Over the last fifteen years the number of regional based data collections have dwindled away to almost nothing.
If the Government does decide to change how and when the ABS Census is collected, what possible impacts would they have?
1. Moving towards a sample survey methodology: Now for the statistically illiterate, please stay with me here. Moving to a sample survey collection would create a lot of evidence basis problems. The nature of sample surveys, is that they are representative only. Surveys select a group of people to represent the rest of us. Now that would be great, if our society was homogenous and unchanging, but no, Australia isn’t. So for example all those small ethnic migrant groups and unusual family formations would be missed and the valuable information about how Australians live would be lost. Regional data would also be severely impacted. A sample survey also means that the data that is spits out isn’t as reliable as a Census. Because the survey is sampled, errors are introduced into the survey and we have to start dealing with confidence intervals which provide us with a range which tells us that the real number could be anywhere between two numbers, i.e. the data is not absolute, it is an estimate only. That means that when the Census tells you that there are 124 people living in your suburb who speak Italian, it’s pretty well correct. But if a survey estimate said there were 124 Italian speakers, depending on the sample size, it could actually be anywhere from 100 to 150; not so reliable or accurate. Canada has recently moved to performing a ‘voluntary’ household survey, instead of their Census, and the consensus is that the data it produces is so completely inaccurate and incomplete that it is unable to inform decision makers about the basic information all governments need to know about the people they govern. Enough said.
2. Repeating the Census every 10 years, instead of 5 years: Yes, it’s possible to do this, and many other countries have (UK), or are contemplating going down this route (New Zealand). The main argument for why we shouldn’t though, is that change in our society can be pretty dramatic over a ten year period. How would we be able to measure the impact or meet the needs of a rapidly changing society if we only had this information every ten years? For example, if a new suburb grew exponentially over a few years, but governments were unable to measure or monitor its progress, that new suburb may not get a high school it desperately needs, or a new medical clinic etc. Infrastructure and planning decisions would be delayed because population changes would be picked up too late or not at all.
3. Obtain information via administrative data instead: Admin data is essentially information that is collected via other collection vehicles, for example, when you put in your tax return it tells the Government not only how much you earn, but how many dependant children are in your household and whether you have a partner, their sex and how much they earn. Valuable information if it could be mined efficiently and effectively by the ABS. I’m usually a big supporter of administrative data and data linking, because it’s so cost effective in getting information, however, it should NEVER be considered as an option for replacing the Census, and here’s why. Try and imagine how many government departments in this country, at all levels of government, collect information about individuals. Now try and imagine how easy it would be to source and collate that data, by negotiating with each individual government department across Australia. I think my head just exploded…i.e. it’s impossible, because the red tape in accessing the data, the many varied ways in which data is collected and stored, the many different definitions used or categories to describe the data that is collected, means that getting an accurate picture of all of Australia would be IMPOSSIBLE to achieve. If you did manage to actually perform the impossible however, it probably would cost more to produce than the Census and would take decades to complete.
Please, please, PLEASE, Federal government of Australia, do not consider changing our Census. We rely on it too much for it to be gambled away just to save some money.