How we track our economy influences everything from government spending and taxes to home lending and business investment. In our series The Way We Measure, we’re taking a close look at economic indicators to better understand what’s going on.

The Australian Census came under intense scrutiny in the wake of #censusfail. Parliament conducted a review, the Senate an inquiry, and some in the media questioned the entire point.

But cost and privacy concerns aside, population is one of the three pillars of the economy.

Understanding population characteristics is vital to inform us of challenges and opportunities, and is a necessary input in other economic indicators. The quality and timely population data found in the census is not gathered through any other means. If changes need to be made, it’s in the discussion around the census.

So we know who is where

The census is unique in that it is a total survey of the population, covering a range of social and economic variables. At present, it is the only way such data is obtained in Australia.

Without the census, we wouldn’t know how many we are, who we are and where we live. This means important planning and policy issues couldn’t be addressed. The location of schools and hospitals, provision of medical facilities, funding for major infrastructure would all be done without an accurate idea of who is where.

In fact, local, state and federal governments rely heavily on data only available in the census. The number of children, working age population, travel to work information, occupations, housing suitability and vulnerable populations is all data only found in the census.

The census also allows for sub-national analyses to be performed, particularly legislated population estimates and projections. These estimates form the basis of economic indicators such as labour force statistics and gross domestic product per capita.

The estimates and projections also highlight inequalities within society, and provide opportunities for policy responses and development at a regional level.

But the purpose of taking a census goes beyond informing resource allocation, taxation and electoral representation.

The statistical benchmarks used in surveys and studies, research and analysis, and, most importantly, lower level aggregates and groups of interest can only be informed by census data. Low level aggregates allow identification of need. Identification of areas with high proportions of young people who cannot access employment or education can provide much insight into barriers to economic participation.

Quality information about homelessness, minorities, and Indigenous populations is only truly obtained via a census.

The data we already collect won’t do

One of the arguments against the census is that we can get the same data elsewhere from the multitude of service providers that already come in contact with the public.

The problem is that these data collections are administrative. They’re collected for a reason and with limited scope.

Centrelink data is collected to provide a service. Information we provide to the tax office ensures tax compliance. Medicare doesn’t keep information about overseas nationals and people who have never had their birth registered, which is an issue in remote and Indigenous communities.

Australia’s large immigrant population would become a blind spot if we were to rely on the data the government already collects, as many aren’t eligible for certain government services. The data collected by Centrelink, the tax office and Medicare don’t provide sufficient scope. So far the census is the only data source that fits the bill.

Some alternatives

Population registers are a viable alternative to our five-yearly censuses. Finland uses a computerised system to record population data including births, deaths, marriages, migration and so on. The Netherlands, on the other hand, conducts a virtual census by pulling together digital data from a number of different sources.

These registers offer real-time data, but they require ongoing maintenance and verification and often exceed the cost of our census. Ironically, they also need to be checked against a census. And Germany’s experience shows population registers are not always accurate.

Further, major legislation changes would have to go through for Australia to be able to pool data like this. The establishment of a national population register would be costly and demand interdepartmental government coordination.

We could also look to the United States’ method of conducting surveys in between a 10-yearly census. This mixed methodology was suggested by the ABS in 2015 to cut costs.

However, limited financial upside, together with lower quality data, makes it a risky alternative for Australia. Plus we shouldn’t think of the census as an unrecoverable cost. The Office of National Statistics in the United Kingdom estimated the costs of their 2011 census were recovered in just over a year.

The future is data

So how can we improve our census?

Online census completion will save money, improve data quality and reduce data processing time. However, online collection must be balanced to ensure disadvantaged populations aren’t excluded. The end of the census collector hasn’t arrived just yet.

More importantly, we must define contemporary data needs moving into the future. An informed public conversation about migration, employment, families and our changing population is much needed to gain social licence to collect and use relevant data.

Whether the methodology of census continues as is or we introduce an alternative method of data collection, the key going forward is the question of legitimacy. Steps must be taken to justify the need to take a census, and to assuage privacy and security concerns. Without social license we’ll see the failings of the 2016 census play out over and over again.

Australia’s future relies on strong evidence we can agree on. This isn’t solely the domain of researchers. We all have a stake.