Academic disciplines provide us with knowledge about the world. But perhaps more importantly, they give us tools to examine for ourselves how the world works. Unfortunately though, most social sciences are missing one crucially important tool: the cost-benefit analysis. Except economics, of course.

Social science teaches the scientific method: how to isolate and measure the effects of one thing. One of the very first (and very fun) laboratory experiments that 100-level psychology students undertake at the University of Otago is the effect of coffee on reaction times: How do the reaction times of those randomly assigned to a coffee-drinking group compare with those assigned to drinking decaf – a placebo? (It’s a blind study by the way, students do not know they are drinking the real stuff).

The point isn’t so much to teach students about the neurological effects of coffee, but the methods for working out those effects. In this case, they use the gold standard of research methods: the experimental study. Those tools can then be taken and applied to other questions about the world, for instance, what is the impact of a given education programme on student learning outcomes?

Social scientists are concerned with two pieces of information arising from an experimental study. First, is the obsession with statistical significance, which essentially asks the extent to which the difference in reaction times between the two groups is due to a real effect of coffee rather than just random chance. That’s where stats comes in.

Second, they are interested size of the effect. The difference may be statistically significant, but it might be barely meaningful.

But the one big part that economics adds in is the cost-benefit analysis. What if scientists discovered a new super drink that boosted reaction times to even greater levels than coffee? For simplicity’s sake, if faster reaction times are the only thing you are after, you would likely choose the super drink over coffee.

But if the super drink costs $8.50, compared to your $4.50 flat white, you might make a different decision. Individuals constantly weigh up these costs and benefits.

When it comes to public policy, however, it gets a bit trickier. Bureaucrats make decisions on behalf of tax payers about how public money is spent. They owe it to them to weigh up not only the benefits, but the costs as well. The Ministry of Education in New Zealand is world-renowned for its Best Evidence Syntheses programme, an extremely useful contribution to education research and policy thinking that looks at the effects of different elements of education. But the missing part is the cost-benefit analysis.

There is room for improvement by adding some economic thinking into the education space.