But how do you measure which approach serves the goal best? You don't just have to agree on a goal, but also on how you measure success (% of people with a degree? % of people completing high school? % of people achieving over 90% in subjects?). Once you get these sorted out, you then have to agree on which policy lever to pull in order to make things happen. And this is where many people differ.

For example, let's say you want to make sure that everyone gets a reasonable-quality basic education (let's say a basic education is to the end of high school). I'm pretty sure most people would agree this is socially desirable. How should the federal government achieve this?

Free market argument: Government is wasteful and inefficient, so a more efficient way of providing education will be through privatisation - competition between market providers will drive down prices, leading to everyone being able to afford a basic education. Quality will be regulated by supply and demand: low-quality providers will go out of business because consumers won't buy their goods.

Public good argument: Because privatising education will actually drive up prices for high-quality education, only richer people will be able to afford a good education. Poorer people will only be able to afford low-quality education. The best way to provide everyone with a reasonable-quality basic education is through free or heavily subsidised public education, paid for through taxpayer dollars.

Both arguments sound reasonable. There's not really a way to scientifically test these theories - you can look at other countries, but none of them is a carbon copy of the exact conditions you have in your country. And there seem to be indications from research that both of these approaches work... but they've been researched in different contexts, again, so they may not work the same in your policy environment.

So which way do we go?