Assortative Mating and Math on "The Bachelor"

Scandal erupted on the Australian edition of The Bachelor when the Bachelor, 32-year old astrophysicist Matt Agnew, asked 28-year old chemical engineer Chelsea McLeod to solve math problems in order to find the combination numbers of a safe on their third and final date before the show's conclusion.

We're not making this up. Here's a video excerpt from the show:

The task greatly upset the show's fan base. Here's the story from the Daily Mail:

Since day one, Bachelor Matt Agnew has embraced the fact Chelsie McLeod shares his same passion for science.

But fans were left confused during the pair's final date on Wednesday's semi-final, as the astrophysicist, 32, tasked the chemical engineer, 28, with math equations.

'This would literally be my worst nightmare!' one fan Tweeted, after Matt described the maths problem as a 'fun activity' for Chelsie to complete.

'I cannot believe you're making me do this right now!' Chelsie said to Matt, which viewers appeared to agree with.

Matt handed Chelsie a pen and paper to solve a math problem to open a safe, which housed a present for the star.

At least it ended well. Chelsie correctly solved the math problems, determined the combination to the safe, and revealed the prize:

After cracking equations, Chelsie typed in the code which opened to a box with a necklace engraved with the chemical formula for oxytocin.

The formula was a reference to their first meeting on the red carpet where she gave him a temporary tattooed of the same chemical.

'So you got to put some oxytocin on my chest, to my heart, and this way, the necklace, it'll be close, some oxytocin near your heart as well.

It's probably no surprise that the two ended up together in the aftermath of the show's suitably romantic final rose ceremony.

But more than just a triumph of math and love, the episode demonstrates assortative mating in action, where couples come together because of their shared potential in addition to their shared attraction. Which in the case of their shared potential, more often than not also reflects their shared earning potential.

But since most couples don't have the accelerated contrivances of a televised dating show to utilize during their courtships, how does that tend to work in the real world?

Alparslan Tuncay described how couples made up of individuals with similar earnings potential come often come together in a paper Marginal Revolution's Tyler Cowen described as "the best results on assortative mating and inequality I have seen". Here's the abstract:

This paper studies the evolution of assortative mating in the permanent wage (the individual-specific component of wage) in the U.S., its role in the increase in family wage inequality, and the factors behind this evolution. I first document a substantial trend in assortative mating, as measured by the permanent wage correlation of couples, from 0.3 for families formed in the late 1960s to 0.52 for families formed in the late 1980s. I show that this trend accounts for more than one-third of the increase in family wage inequality across these cohorts of families. I then argue that the increase in marriage age across these cohorts contributed to the assortative mating and thus to the rising inequality. Individuals face a large degree of uncertainty about their permanent wages early in their careers. If they marry early, as most individuals in the late 1960s did, this uncertainty leads to weak marital sorting along permanent wage. But when marriage is delayed, as in the late 1980s, the sorting becomes stronger due to the quick resolution of this uncertainty with work experience. After providing reduced-form evidence on the impact of marriage age, I build and estimate a marriage model with wage uncertainty and show that the increase in marriage age can explain almost 80% of the increase in assortative mating.

Marrying later contributes to this outcome because it allows the each partner in a couple the time to demonstrate their earning capacities, which would either reinforce the pairing or lead to a break up if the two are incompatibly mismatched. Tuncay's findings confirm what we've seen in the data for income inequality in the United States over that period of time, where there has been no change in the income inequality level for individuals, but a rising trend for both households and families as a greater emphasis on college education and early career establishment before marriage has become common in American society since the 1960s.

Assortative mating provides a very reasonable explanation for these outcomes. And we've just seen it at work, in all its oxytocin-enhanced sweetness, on The Bachelor Australia.