Labor faces another great moral challenge of our time. It's not going well

What drives the latter when the former should be obvious? Fear. The fear of incurring enough wrath of the interest groups to prod them into big misinformation campaigns unless they ditch the offending policy. The mining industry's campaign against extra resource taxes in 2012 and 2022 are good examples.

That's the theoretical. Now to the specific. For more than 20 years the Labor Party has accepted the compelling evidence and science of climate change. Dealing with climate change was described by then opposition leader Kevin Rudd in 2007 as the great moral challenge of our time.

Now Labor in government faces another moral challenge with similar evidence of damage - gambling.

It is about to make a decision on whether to agree with a ban on online gambling advertising as proposed more than a year ago by a parliamentary committee headed by the late Peta Murphy, one of Labor's most respected MPs.

The gambling, sporting, pubs and clubs, and television industries have gone into a frenzy of "sky-falling-in" reactions. Television will not survive the loss of income, they say. Football and other sporting codes will collapse.

The big problem for them, of course, is the evidence. Submissions to the parliamentary committee and its hearings demonstrated the harm. It was followed by a report from the Grattan Institute.

They concluded that the gambling "industry" relies heavily on heavy gamblers' losses for its revenue. Three-quarters of gambling spending comes from just 5 per cent of all gamblers, and they are nearly all heavy gamblers. About 1 million people either suffer, or live with someone suffering, from severe gambling harm.

Well, if television companies and sporting codes have to rely on that sort of misery to stay in business, then maybe they should go out of business. But they don't. It is hype and misinformation.

To demonstrate that, let me refer to one of Labor's champions of evidence-based policy: the Assistant Minister for Competition, Charities and Treasury Andrew Leigh.

Leigh, who was a professor of economics at the ANU before entering policy, has made a cogent case for governments to use randomised trials whenever possible to decide whether a policy works or should be junked.

Randomised trials have been used for decades to test the efficacy of drugs. One group gets the new drug and the other gets a placebo. If the drug is effective, useless, or has harmful side effects, it is demonstrated by whether the placebo group had a different result.

Leigh says the method can be applied more broadly. For example, in education, one group of schools could continue to give suspensions for misbehaviour and another could apply a new approach not involving suspensions. After a time, the results could be compared and policy changed, or not.

Leigh's approach has a lot of merit and governments should listen more to him.

I think more can be made of this because, as it happens, Australia's federal system provides almost constant randomised trials across the policy spectrum.

Perhaps the most well-known was Victoria's introduction of compulsory seatbelt wearing in 1969 against all the civil-liberties squeals (the right to unnecessarily expose yourself to death). The Victorian road toll plunged. Other states had no choice but to follow.

Similarly with gambling. In Western Australia, pubs and clubs are not allowed to have poker machines. They are confined to the casino. Western Australia has a thriving pubs, clubs, and sporting culture. Other states and territories should follow suit. Bizarrely, in the ACT poker machines can be licensed in pubs and clubs but they are prohibited at the casino.

The world will not end for pubs, clubs, TV and sport if gaming advertisements are banned or poker machines removed - unlike the way the world too frequently ends for vulnerable people lured into gambling addiction. And the TV advertising spots will be filled by other things, just as they were when tobacco advertising was banned.

To counter the way the TV, gaming, pubs and clubs, and sport lobbies instil fear in politicians, voters concerned about gambling's damage should go to the Australian Parliament's website's list of senators and members and click on the email link to their local government member (or senator if not a government one). Then they can send a message saying they will give their first preference to a minor party or independent unless the government does something about gambling. Similarly, if the Coalition opposes action.

These days that message instils fear because there is no longer any inevitability about the preferences trickling all the way down to one or other major party.

MORE CRISPIN HULL:

Speaking of evidence-based policy, when will business lobbies and governments stop ignoring the obvious causes of Australia's housing crisis? How does the government imagine that pouring vast amounts of money into demand- and price- boosting schemes purporting to help a few tens of thousands of people into housing will do anything much to solve the crisis in the face of out-of-control immigration of hundreds of thousands of people and a tax system that encourages investors over home-owners?

The government's admission this month that it "missed its target" on immigration confirms that Australian governments lost control of the borders with the introduction from about 2000 of labour- and student-import schemes under which visas legally have to be granted if the applicants tick the right boxes - irrespective of how many visas might be granted in any year.

To control the borders, Parliament should set a number, and applicants over that number should be delayed to the following year.

It is within the power of the federal government to control this, not to have some woolly "target", which may or may not be met.

Unless Labor gets this under control it will become the electoral victim of Coalition dog-whistling.