By Claire Grealy | 14 Sep 2016

This article was written by senior consultant Joanna Farmer.

For the last few weeks, the Census has been in the news. Despite, or perhaps because of, the setbacks on that Tuesday night in early August, debate has been ongoing about the need for a Census in the information age.

For economic and social researchers and evaluators, this is an important debate to have given the importance of accurate data for policy making.

A common argument against the Census is the notion that we hand over so much data to public and private entities in our day-to-day lives that there is no need for us to ‘take a pause’ and provide seemingly basic information on Census night. While it’s true that there is now a great deal of ‘big data’ stored across the country, the extent to which it is accessible by researchers varies.

Importantly, very little of this stored data is accessible in a form that allows it to be linked to other factors that provide important context. The ATO may have information about people’s incomes, but the Census can add an extra dimension by understanding the relationship that has with family structures and cultural backgrounds, providing more nuanced policy responses that account for people’s context and location.

To understand the whole population, you need a Census.

Additionally, it’s important to understand that a lot of the data that exists in other forms is incomplete for providing a complex and textured picture. For example, the Victorian Population Health Survey is an incredibly valuable survey that provides an insight into the health and social needs of the Victorian population. It is a huge survey – with 34,000 participants.

However, it is still not possible to draw statistically valid conclusions about the health needs of Victoria’s Aboriginal population from a sample of this size. It is particularly important that we are able to make accurate determinations about priority populations, regardless of their numbers. While the Census does not cover health information, it still provides important demographic information that drives social investment and infrastructure. It seems obvious, but when everyone is counted, no one is missed out.

But more fundamentally, the Census is important for helping to understand the other data that we do have. It’s hard to understand if a survey of 1000 Medicare users is representative of the whole population if you don’t understand that whole population. To understand the whole population, you need a Census.

Researchers and policy makers can often expect statisticians to be magicians: to determine whether the numbers ‘make sense’ and demonstrate statistically significant change. To do that, you have to understand how data works: who is in the sample? Why is there missing data? Are there consistent characteristics among the people who are responding to your survey, and those that aren’t? How can we make sure that minorities and the hard-to-reach get a voice in policy development?

The Census allows you to make sense of other data by providing a reference point to adjust your data, to ‘weight’ it, to build a more representative picture.

Yes, there is a lot of data out there. But the Census is the one data source that our team relies on daily to help evaluate, understand and develop effective policy interventions. So this is one researcher’s plea for you to complete your Census before the deadline (23 September) to help shape your cities and communities for a better future.