2018 saw a surge in people working in secondary jobs that has led to the first time there being more than one million people working multiple jobs. The surge was most pronounced in the last half of 2018 where 30% of the new jobs created were going to those already working in another job.

The period of extremely low wages has clearly come to bite workers, with more people now than ever before seeking another job to help pay the bills. The latest quarterly labour account released last week shows that while the growth of main jobs has slowed the number of secondary jobs has accelerated.

The labour account, unlike the monthly labour force figures, measures jobs not just “employed”. As such it is able to provide greater detail on what has led to the strong employment growth of the past two years.

Over the long-term secondary jobs generally rise along with main jobs; but since the end of 2016, secondary job growth has become much more pronounced:

And the real surge occurred in the past year. Whereas the quarterly growth of main jobs slowed and then plateaued, secondary job growth steeply rose – hitting 3.4% in the September quarter of last year:

It is a damning statistic for the government, which has prided its economic ability on the fact that employment has risen. Since December 2017, when secondary jobs accounted for just over 6% of all jobs, they have accounted for a quarter of the increase in jobs.

It has led to the position where now more than 7% of workers have at least two jobs:

The labour force figures count full-time employed as anyone who works more than 35 hours a week – regardless of how many jobs they do to reach that number. The growth of secondary jobs would suggest a rise in multiple job holders being classed as “full-time”.

For the most part, the industries that employ the largest numbers of people in “main jobs” are also those who employee the most in “secondary jobs”. The big exception is the administration and support industry which holds 5% of all main jobs, but accounts for 24% of all secondary jobs:

And while not surprisingly the industries with the highest percentage of part-time employees also had the highest percentage of multiple job holders, administration and support is again a big exception.

While 42% of those employed in the admin and support industry are employed part-time, 26% of those working in the industry are working multiple jobs. This compares with the health and social assistance industry which has a similar percent of employees working part-time but just 6% of whom are working multiple jobs:

This would suggest that those part-time employees working in industries such as retail trade, and accommodation and food services are more likely to view their job as their main job and wish for more hours in that job:

That the administration and support industry has a below average level of underemployed goes to the nature of the industry where working for different companies is less of an issue and more likely given the temporary employment nature of the industry. Whereas you are less likely to see someone working in two different retail stores or hospitals.

But the overall increase in secondary jobs has also seen a sharp fall in the average hours worked per job.

Just two years ago the average job saw a person working for 29 and half hours a week; now that figure is down to 28.9 hours:

The last two years – and especially 2018 – has seen the consequences of the low wages growth flow through. Very few people work more than one job for the fun of it – you seek out more jobs because your main job does not pay enough for you to make ends meet.

The growth of secondary jobs highlights the impact of stagnant household incomes and the shift towards part-time work. It has resulted in the labour market shifting to one that is less able to allow people to survive on one income than ever before.

• Greg Jericho is a Guardian Australia columnist