Watching Avengers: Infinity War, I felt the pain and guilt of Tony Stark as he saw Peter Parker disintegrate. My heart broke when my favorite doctor found no possible way to defeat Thanos, and just accepted the fact that he, together with half of the universe, would turn into dust. That’s why I’m looking forward to a possible time-travel solution in the upcoming movie, Avengers: End Game. But if they really want to stop Thanos and save the universe, Captain America, Ant Man, and the surviving superhero crew should time travel to when Thanos was a teenager and convince him to not skip his macroeconomics class. If only he had learned about the Solow Model, things would have been very different.
[Be advised: spoiler alert!] Thanos claims he actually wanted to save the universe by wiping out half of its population – to make sure what happened to Titan, his homeworld, would not happen to the rest. He believes overpopulation will lead to self-destruction. So why not simplify things and give half the universe a better chance at surviving?
Thanos probably slept through most of his macroeconomic class and only woke up for the Malthusian growth model. In 1798, Thomas Robert Malthus published An Essay on the Principles of Population, in which he claimed populations tend to increase at a faster rate than food production. This was a challenge for future generations – who would have to fight over resources or starve. This is what the Malthusian growth model predicts will happen, and thus, Malthus concludes, population growth should be controlled.
Enter the Industrial Revolution. In his model, Malthus disregarded technological changes and capital accumulation as a way to improve people’s standard of living. Thanks to genetically modified organisms (GMOs), farm tractors, and advanced irrigation systems, for example, food production is booming despite the drastic increase in population size and limited land space. Luckily, in 1956, Robert Solow published A Contribution to the Theory of Economic Growth, in which he developed a model that accounted for those changes.
Based on the Solow growth model, Thanos made a huge mistake. In the long run, each world is worse off as there will be plenty of capital but not enough labor to turn it into output. Growth has been compromised and the population left behind might actually be worse off! Luckily, we haven’t reached the end of the story yet. Let’s hope in the next Avengers movie, our favorite Marvel superheroes can teach Thanos a thing or two about the Solow growth model.