I’d be surprised if Jane Public didn’t think there are 457 visa holders hiding in her closet, given the misinformation in the media over the last couple of days.

Last night on ABC PM, Martin Cuddihy told listeners there are more than 80,000 workers on 457, or temporary employer-sponsored, visas in the Australian workforce. While the latest departmental statistical report does indeed say there are 83,840 primary 457 migrants in Australia as at December 31, he is incorrect to refer to this number.

Why? Because it excludes all the migrants who like to go home for their holidays. The real figure is about 100,000; in November 2012, there were a total of 103,430 primary 457 migrants in Australia. Almost every journalist has reported the 83,840 figure, which is out by more than 20%.

Cuddihy makes two further errors. First, he says this 83,840 figure is “about 5% of the workforce”. I hope he isn’t talking about Australia, because if he is our labour market just shrank by about 10 million people. Workers on 457 visas make up between 0.8% and 0.9% of the workforce.

He also states: “Almost two-thirds of those people have a university degree or post-graduate qualification.” It is true that about 65% of all 457 migrants are managers or professionals, but that doesn’t mean they hold any type of formal education. Under the visa approval process, migrants can substitute formal qualifications for past work experience.

In addition to misstating the number of 457 visa holders in Australia, The Australian also reported “applications for the visas fell by 4.8% in the six months to December 31”. This is blatantly incorrect. The figure of -4.8% is actually the number of visa applications lodged offshore. Onshore visa applications rose 30.1% during that time, for a total growth rate of positive 9.7%. Today The Australian reported the updated figure (though the December figure is still reported in the previous article).

That 105,325 is the highest number in the program’s history.

Mistakes happen. But when this issue is arguably the most visible at this early stage of the election campaign, media outlets have a duty to get the basic facts right.

Migration is a difficult, complex and nuanced area of public policy. I don’t understand even half of what goes on in the immigration space, and I worked in the Department of Immigration and Citizenship for nearly five years and now I work for the Migration Council Australia. Yet this is why it is so disappointing to see the best Australian journalism has to offer making such mistakes. Public debate should be grounded in a set of facts we can all agree on, and that means knowing the basics about policy areas that are in the news.

You might think 457 visas are the best thing since sliced bread (I know I do) or you might think migrants steal jobs (you’d be wrong, but that’s for another time). But you should have a basic understanding of at least how many migrants there are so you can judge for yourself what politicians say and do with public policy in this country.