Gladys Berejiklian proposes to knock down two perfectly functional football stadiums and replace them with – wait for it – two new ones. Apparently, all that demolition and construction will create jobs in demolition and construction. And, apparently, the reason people don't attend football matches in Sydney is because of the stadiums, not the football. NSW taxpayers are about to spend $2 billion testing that hypothesis. But if the government is right, it's the football codes, not the taxpayers, that will pick up most of the extra revenue.

In my book, Curing Affluenza: how to buy less stuff and save the world, I argue there is a big difference between consumerism and materialism. Consumerism is the love of buying things whereas materialism is the love of the things themselves. While shop owners might get rich selling us new things all the time, we can't get rich if we spend a fortune on new things to replace perfectly functional things.

Put simply, if we want our nation to prosper, if we want to pursue efficiency or if we want to minimise the harm we do to the natural environment, then we need to love, repair and maintain our things. We need to avoid waste and invest our time, money and resources in things that will deliver us lasting benefits, not fleeting pleasure.

But as the NSW government shows, it's not just individuals who can fall into the thrall of consumerism. Like bored shoppers, government ministers can fall into its thrall, too, and believe that shiny new things are the secret to economic or political success.

While the decision to buy some new stadiums has backfired badly, you can see how the Berejiklian government fell into the trap. Everyone knows you get more news coverage announcing a brand new stadium than announcing brand new seats for an old stadium. Everyone knows that the sporting codes, their sponsors and the other hangers-on will love you more for shiny new corporate boxes than for new carpet in the old ones. And we can only imagine the sales pitch from the stadium salespeople (otherwise known as property developers): "C'mon, minister, you can't put a plaque on a renovation ... No one remembers the guy who got the repainting done ... You deserve a legacy."

The problem of desiring the new rather than maintaining the old isn't confined to building new stadiums. Modern ministers seem to love rebranding and rebadging as much as they love restructuring and reforming. But as anyone who has ever worked in a large organisation (public or private) knows, such changes are often as pointless and symbolic as the "exciting" new bumper bars and blinker casings that constitute the release of a "new" model of car.

Rather than ensure that their departments operate effectively, the modern minister loves to introduce "big changes" designed to show everyone, or maybe just themselves, how important their job is.

Take Barnaby Joyce, for example. While it was widely reported that he ignored departmental advice against spending tens of millions of other people's dollars to move the Australian Pesticides and Veterinary Medicines Authority from Canberra to Armidale (in his electorate), what is much less discussed is that such opposition is central to his political strategy. What's the point of being a minister if all you do is take advice? How can you brag to your electorate about how powerful you are if you only make sensible decisions?

Joyce isn't alone. Matt Canavan was far keener to give $1 billion of other people's money to Adani than north Queenslanders were, and I'm yet to meet an Australian who is excited about receiving the $50 billion worth of joint strike fighters that successive defence ministers have been determined to give us.

At Christmas time, most of us take for granted that we will receive gifts we don't want or need. But it doesn't need to be this way.

The job of our elected representatives is not to give us "surprise" presents that we don't want, nor to use our money to make themselves feel good or look powerful. Their job, be they backbenchers or ministers, is to consult those they serve, identify options and opportunities, and seek the public's endorsement for their proposed action.

While it is often said that, in the age of Twitter, it is simply impossible for governments to do something as old-fashioned as carefully developing policy, consulting widely and communicating the benefits of change effectively, such fatalism about the role of government is entirely wrong.

The fact that successive federal governments have struggled, or failed outright, to drive major reforms is not evidence that modern communication technology makes governing impossible. It is evidence that the last few federal governments found it impossible. Plenty of other countries around the world have managed stable government and major policy change – despite the existence of Twitter.

Closer to home, the ACT Labor/Green minority government has delivered a 100 per cent renewable energy target, land tax reform and massive investment in light rail. The Liberal opposition criticised each of those changes, which all became controversial election issues. But the electorate endorsed all of them and, while some have been a decade in the making, all are now being implemented.

Building new things and introducing new policies is an important part of governing, but so, too, is maintaining the things we already have and making sure they work well. While it might be more fun to launch a new policy or use a silver shovel to turn the first sod on a big project, what we really need in Australia is fewer big ideas and big investments, and a new conversation about what we really want our nation to have more of and what we are willing to go without.

It's the shape of our economy that affects our lives most, not the size of the economy. Rapid growth in automated coal mining will increase GDP, but it will not increase employment nearly as fast as rapid growth in labour-intensive sectors of our economy. Just as it is not the price of the stuff we get for Christmas that makes us happy, but the thoughtfulness of it, it is not the amount of money our politicians spend on new infrastructure that improves our lives, it is whether they invest in the things we really need.

Richard Denniss is The Australia Institute's chief economist. Twitter: @RDNS_TAI