Last year, the federal Member for Fraser sobered us up with Battlers & Billionaires. Now comes his spritely The Economics of Just About Everything.

The previous book analysed the rising inequality that's dogged Australia and other rich nations since the 1970s. Who'd have thought this seemingly dry topic would go on to make a celebrity of French economist Thomas Piketty (Capital in the Twenty-First Century) and embroil this year's federal budget?

Leigh's eclectic new book paints economics as "everywhere" and "fun". It links private behaviour to public policy, whether in love and marriage, health and sport, wages and careers, or poverty and crime. Once again, the author draws on his own economic research.

For a graphic illustration that human behaviour does respond to (financial) incentives, why not look at births and deaths? It turns out Costello's baby bonus shunted a statistically significant number of births from June into July 2004. Abolition of death duties, decried in the earlier book, had an analogous effect. Somehow, fading hearts beat on, from June into July 1979.

Finding a mate can solve a loneliness problem. To an economist, it can solve an "optimal-stopping" problem. In which you're at liberty to keep checking out new dates (new information) ad infinitum, but a better trade-off is to settle sometime for a semi-ideal someone.

The numbers narrow down this tricky challenge. The first table says marriage is more likely to stick if you finish year 12 and wait until your 20s. The caution is that the "cost of two children for the typical Australian family is $1.4 million". Nearly half of which is the mother's foregone earnings.

Our marriage statistics discount Team Australia's gay couples. But they can leverage their higher disposable incomes, so the theory goes, to identify and inhabit our more liveable cities. Higher proportions of gay couples, Leigh finds, nestle in Canberra, Sydney and Melbourne.

The chapter Fit For Tomorrow characterises health and safety issues as "time inconsistency" problems. In other words, we make dumb decisions today despite the costs tomorrow.

I'm persuaded that governments' strong actions and stark information have reduced Australia's smoking and road-death scourges. I'm less sure about the line on obesity. Sure, we can't "turn the clock back on microwaves, vending machines and tastier foods". But must the weight challenge remain largely "personal"? As the economic costs of our fat/sugar/salt addictions mount, governments might be more inclined to counter the political and market reach of the processed-food and supermarket giants.

Battlers & Billionaires explained Australia's serious shifts in wages and wealth distribution. The serious wealth point here is, get an education. Year 12 school-leavers can expect $2.1 million in lifetime earnings, against $2.9 million for degree-holders.

Men and women, Leigh continues, tend to earn more if they're taller or prettier. Nevertheless, the average female still earns less than the average male. In lower-paid jobs, this gap may be attributed to lower productivity. In higher-paid jobs, it looks like bias.

Leigh has taken a particular interest in foreign aid and crime research. He argues that Australia should play to its "comparative advantages" in foreign aid. He tags these as mineral resource extraction, dryland farming, and post-conflict situations.

I didn't know the personal motivations behind his crime work. He's a distant relative of the Hoddle Street mass-murderer. He knew one of Martin Bryant's 35 Port Arthur victims of 1996.

John Howard's feted gun buyback gives Leigh a stage to rehearse the unintended effects of incentive programs. His subtle statistics say the buyback's big plus was cutting gun homicides and suicides, not massacres per se. Then, who knew legalised abortion and unleaded petrol could slay violent crime?

The author turns to elite sport and art, although their performers and audiences don't always behave economically rationally. I enjoyed these chapters, both for questions raised and answered.

Leigh correlates nations' GDPs and (London 2012) Olympics medals. In the lead-up to London, he says, Australia's GDP growth left Britain's for dead. This doesn't help with the sports shock that's tormented us Olympics tragics. For the first time since Seoul 1988, Team GB thrashed Team Australia in the medals.

For an interesting theory on art, it's over to University of Chicago economist David Galenson. At great empirical length, apparently, he's classified successful artists as "conceptualists" (who implement imaginative theories and peak early) or "experimentalists" (who like observed reality and tend to peak later).

Leigh's tables gamely adapt Galenson to Australian painters, rock musicians and novelists. This exercise works much better than I would have expected. Do conceptualists or experimentalists, I then wondered, win out in lifetime earnings? Or what would the theory make of Australian artists who bloom early then flower again? Say, The Church in rock music, or poet and novelist Randolph Stow.

If economics is fun, economists' forecasts are a drag. Leigh lists crucial items they struggle to forecast, including inflation, economic growth, population, employment, share prices and exchange rates. Where possible, one should swap the "experts" for "prediction markets" or betting markets. Practising what he preaches, the author used the punters' odds to guide his AFL tipping entries.

Who really can forecast, at least short-term, are our much-maligned meteorologists. Plus, their weather statistics seem to predict wine futures. Hence Leigh's final table, using weather data to predict Grange vintages.

Think twice about so-called "active" money managers is one obvious recommendation that Leigh derives. Above all, "think about incentives, recognise trade-offs, don't fall for the sunk-cost fallacy, play your comparative advantage".