The year has ended well for the treasurer. The latest job numbers out this week show that employment growth remains strong and Monday’s mid-year economic and fiscal outlook (Myefo) is likely to show a smaller deficit than was projected in the May budget. But amid that good news is a notable indicator of the problem that has cast a pall over all the economic news this year.

The Myefo is essentially the last major economic news for the year. There isn’t any more big data to arrive from the ABS (which, like the rest of the public service, will shut down between Christmas and New Year). And even the Myefo is not expected to be altogether surprising. There have been reports about new cuts to university funding, but the big picture is mostly known, and it is mostly good news for the government.

The likelihood is the Myefo will reveal that the 2017-18 budget will come in with a significantly smaller deficit than was predicted in May.

The latest monthly figures from the Department of Finance show that in the first four months of this financial year the government received $3.2bn more tax revenue than expected and spent $870m less than predicted in the May budget. So right now the budget for 2017-18 has a $3.5bn smaller deficit than expected. If those revenue figures continue to outperform expectations for the next eight months, then the surplus is going to be rather smaller than the $29.4bn forecast in May.

What is driving that extra revenue, however, highlights the fractured nature of the economic growth we have experienced this year.

There is no doubting that employment growth has been superb this year. Off the back of major public infrastructure programs and the healthcare and social assistance industry, employment has now been growing for 14 months straight – the best run since the early 1990s.

Even better is that full-time employment is also growing well. At the start of this year the number of people working full-time was actually lower than it was at the start of 2015. Since then, 296,000 more people have begun working full-time – a 3.8% annual increase that is as good as we’ve seen for nearly 30 years. You have to go back to 1989 to find annual full-time employment growth faster than we are currently experiencing.

And even if you are churlish and suggest this year is just making up for last year’s horror run, the past two years still had the strongest full-time employment growth since 2011-12.

So all good news.

And yet, when you look at the government’s financial updates, the big improvement in tax revenue does not come from income tax, even though the May budget predicted employment would only grow by just 1.5%, whereas it is currently running at 3.1%.

The amount of individual income tax the government has received this financial year is actually a touch over $800m less than expected. This is because although the government predicted weaker employment growth than is currently occurring, it also predicted stronger wage growth. The May budget hoped that wages would grow in 2017-18 at 2.5%, whereas they are rising by just 2.0%.

So what has delivered the bonanza of tax revenue? Companies.

Thus far the government has received $3.7bn more company tax revenue than they were hoping – 19% above that predicted in the May budget. So big has been this tax bonanza driven by rising coal and iron ore prices that if it were to hold, the government is looking at an extra $14.7bn in revenue over the course of 2017-18. Now that is very unlikely to happen, but it gives you a sense of just how much of a revenue boom there has been.

So company profits up by more than expected has led to better company tax revenue, but workers, despite more people working than expected, are delivering lower income tax revenue than anticipated.

That is an apt result given the biggest economic story of the year was the decision by the Fair Work Commission to cut penalty rates on weekends for retail, pharmacy, fast food and hospitality industries.

The drive of economic policy this year has all been towards stronger company profits and the hope of higher wages to come, while at the same time policy levers have been geared towards keeping wages low – whether it be through inaction on penalty rates or move to limit the ability of unions to effectively negotiate for higher wages.

It highlights the issue the Governor of the Reserve Bank has noted that “the normal tendency for firms to pay higher wages in tight labour markets appears to be muted”, because “businesses are not bidding up wages in the way they might once have”.

At least here there might be some better news ahead. One issue has been that although unemployment has been falling, underemployment had been rising throughout the year. But the November labour force figures showed that the underemployment rate had fallen from 8.6% to 8.4% – a move that should see wages growth improve a touch.

That is at least the theory, and it will be watched closely. This year has been all about companies and investment and the recovery in the jobs market. Next year will be all about whether or not this foundation leads to strong wages and household incomes growth.

If it does, the prospects for an early election will rise; if it doesn’t, expect industrial relations to be a major political battleground for whenever the government chooses to go to the polls.