An economist reviews Dan Brown's 'Inferno'

Warning: Spoiler Alert below the jump.  If you haven't read 'Inferno' yet, don;t read below the jump, I'm going to give away the plot and ending.

I recently finished reading Dan Brown's (author of The Da Vinci Code) newest book 'Inferno.' As a casual reader of the book, I found it entertaining.  Brown does his typical job of keeping the action moving, mixing in some interesting conspiracy theories, making me want to visit some cities I've never been to, and making it seem like being a college professor might be cool (although I have my doubts).  I didn't enjoy it as much as The Da Vinci Code, which I didn't enjoy as much Angels and Demons, but still a good read (and I refuse to accept that The Lost Symbol was written). 

But, as an economist, I found the book to be complete nonsense. 

Why?  Read below the jump (SPOILER ALERT AGAIN).

The premise of 'Inferno' is pretty simply, a Malthusian nut job is convinced the world is overpopulated, the end is near and everyone else (the World Health Organization, the Catholic Church, and anyone who has babies) is to blame and willing to turn a blind eye.  To remedy this, the Malthusian nut job--who also happens to be a genetic engineer--decides to develop and unleash a 'plague' that will cut the world population by 1/3--which is apparently the right number of people to have around.  The Malthusian nut job leaves clues as to his plan by referencing Dante's Inferno and some of the renaissance art work based on Dante and his works.  Harvard Symbologist Tom Hanks, er Indiana Jones, er I mean Robert Langdon, has to unravel the clues while finding yet another hot chick to hook up with. 

It's good to be a Harvard symbologist. 

They get all the chicks.

Anyway, I digress. 

The twist in the book comes when it is revealed that the 'plague' that the nut job has developed and unleashed is not the Black Plague, which Professor Langdon has presumed all along, but rather a new genetically engineered vector virus (is that a real thing?) that will randomly alter the DNA of  1/3 of the population so that they are sterile and the resulting genetic role of the dice is hereditary.  So, in the mind of the nut job (and presumably Dan Brown), the result will be a steady state in which 1/3 of the population is sterile, thus restricting the population to be 1/3 of what it is today.  That's where the book ends (and yes, the 'plague' does get out and spreads around the world in less than a week).

So what problem does my inner economist have with 'Inferno'?  Simple, Langdon, or Brown, or the nut job, or whoever you want to name, fails to account for the unintended consequences and resulting incentives of sterilizing 1/3 of the population.  Right now, 99% of the human population (or some high number) wins the genetic lottery and is physically able to reproduce.  If the supply of fertile humans is reduced by 1/3, the value of being fertile will increase.  As a result, there will be societal pressure to increase the birthrate among those who win the new genetic lottery.  The fertile class becomes more valuable to society, average birthrates for the fertile will increase and the infertile wil become a class of outcasts.  Will this reproduction rebound effect be enough to outweigh the 1/3 decrease in the fertile population? I have no idea, but I can imagine religions and governments and the like developing policies, moral imperatives and social norms to encourage the fertile class to make more babies, thus creating a new Malthusian dilemma. 

Sometimes being an economist ruins an otherwise enjoyable reading experience.