The review delves into seemingly intractable problems of congestion, urban sprawl, development entanglements, renewing and adding to infrastructure, and so on, suggesting all sorts of better processes, incentives and disincentives.

Don't get me wrong. The suggestions are well-thought-out and try to weed out the worst sort of rent-seeking and political machinations. But they are all curative of problems without mentioning one of the main underlying causes: rapid population growth.

It is astonishing that one of the most-respected economic institutions in the country can do a five-year review of productivity without some detailed discussion of population policy and what effect the ramping-up of immigration since the Howard years, including Kevin Rudd's "big Australia", has had and will have in the future.

In the year to March 2017, Australia's population grew by 384,000. Of that, 217,000 (about 60 per cent) was net overseas migration. This means Australia needs to build the equivalent of a city like Canberra every year to accommodate this growth.

So what's the point of delivering an immensely detailed five-year review if all its recommendations are compromised by a population non-policy, under which, every year, the government plucks a figure from the air with precious little concern about long-term economic effects.

It is completely negligent for those such as the Productivity Commission, nearly every federal and state politician, and a raft of greedy special-interest lobbyists to couch the issue as "What do we do to accommodate this population growth?" instead of "How can we reduce the population growth?"

For example, the commission says we should impose road-use charges, the equivalent of a congestion tax, to deal with traffic congestion and its huge economic costs. And state governments should build more expensive roads in a futile attempt to catch up. This Band-Aid, treat-the-symptoms approach is not just negligent, it is outright dangerous.

The danger lies in opportunist political figures like Pauline Hanson linking the ills of overpopulation (congestion, hospital waiting times, housing prices, stalled wages growth and the like) to Muslim immigration. The more that people who profit from high population growth and do not suffer the consequences (business, lobbyists and the politicians they fund) blithely ignore the infrastructure and other stresses it causes, the more chances there will be for opportunists.

We should change this trajectory. Australian Labor, for example, could borrow from New Zealand Labour. I do not mean replacing a dull grey man with a vibrant young woman, but rather changing the big-population policy without any dog-whistling about refugees or Muslims (who, incidentally, comprise just 2.2 per cent of the Australian population).

Yes, electoral trends have shown more support for bright young things in Canada, France and New Zealand, but the electoral trends show a darker side in other places: Brexit, Donald Trump and growing support for far-right nationalists in Europe. The New Zealand approach is better.

In Australia, we should celebrate the wonderful things immigration has done for our economy and society in the past. But we should not put that in jeopardy with too much immigration now. Australian government have frequently cited opinion polls, mainly by the Scanlon Foundation, as saying there is popular support for immigration in Australia.

That is no longer the case, or the earlier polling did not accurately reflect public opinion.

Polling this week reveals just how dangerous the present approach is. Katharine Betts and Bob Birrell, of the Australian Population Research Institute, found that "74 per cent of voters thought that Australia does not need more people, with big majorities believing that that population growth was putting 'a lot of pressure' on hospitals, roads, affordable housing and jobs".

Alarmingly, they found: "Most voters were also worried about the consequences of growing ethnic diversity. Forty-eight per cent supported a partial ban on Muslim immigration to Australia, with only 25 per cent in opposition."

This is a dangerous path. When prime minister, John Howard adopted a tough approach to refugees because he thought to do otherwise would erode support for immigration.

Well, forget the refugees, who are only a few per cent of total immigration. Support for immigration has eroded because of too much immigration.

If political parties want to retain or boost their public support and want to retain modest immigration, they should drastically reduce the number of people coming in before the "ban-Muslim-immigration" sentiment takes hold and is exploited by the unscrupulous.

The new survey says 54 per cent want to reduce the migrant intake. This includes 57 per cent of Coalition voters and 46 per cent of Labor voters. This result is far higher than the 34 per cent of respondents wanting a lower migrant intake reported in the last Scanlon survey in July-August 2016.

These figures show the Coalition has more to lose if it does not respond to these concerns. It puts the Coalition in a difficult position. Its main business donors, of course, profit from high population growth, but it seems that more Coalition voters are feeling the pressures that comes with it.

The important thing now is for the main parties to forget the wishes of their donors and concentrate on the wishes of voters – before One Nation, the Australian Conservatives and others exploit the discontent in an ugly way.

And key parts of the bureaucracy should not take high population growth as a given and advise only on how to cope with it, but also advise on its downside and how it can be checked.

crispinhull.com.au