If you're reading this, then chances are that your way of life is default dead. Now, that's a hell of a thing for me to say to you, given that I probably don't know much about you, so let me elaborate a bit and I think you'll come to see that the logic of what I'm saying is inescapable.

We'll start with default dead.

Default dead is a term coined by Paul Graham, a venture capitalist, to describe the state of some of the startups in which he has invested. The nature of startups is that they begin with a rudimentary product, very little money, and, at most, a handful of customers. Then they borrow money from venture capitalists like Mr. Graham in the hopes that they can hire employees, get their product to market and, eventually, acquire customers.

It's the 'eventually' in that last sentence where the concept of default dead arises. Because venture capitalists will only lend a startup so much money. And if a startup has hired a bunch of employees, then the money they've borrowed will eventually run out. This is the point Mr. Graham makes in his essay: if things continue as they are—if a startup keeps spending money and adding customers at its current rate—will it run out of money before it's able to bring on enough customers to become profitable? Or, in other words, does continuing on its current trajectory mean that the startup is default alive or default dead?

This question is important, because, if you're default dead, nothing else matters. There is a ticking clock which is counting down the time until you go out of business. The only thing you should be focused on is getting yourself to a position where you are default alive. And Mr. Graham points out that borrowing more money is not a viable fallback strategy, because, paradoxically, the more desperately you need the money, the less willing people will be to lend it to you.

But enough of venture capital and the world of startups, because this concept is applicable on a much larger scale. Essentially, if you're from the developed world, and you're not super religious, then your way of life—your culture—is probably default dead. That is, if things continue on their current trajectory, your way of life will eventually cease to exist.

The reason that this is the case comes down to demographics. Specifically, it comes down to the replacement fertility rate, which is the number of children each woman must have in order to prevent the population from decreasing. In the developed world, the replacement fertility rate is 2.1 children per woman (the .1 is to account for people who die before the end of their fertile life). And keep in mind that this number is an average, so if some women are having 0 or 1 children, then there need to be enough other women who are having 3+ children to get the average to work out to 2.1 children per woman.

If the fertility rate of a culture drops below this number, then it will start shrinking. If it rises above this number, then it will grow. Or, restated in terms of our earlier discussion: if the fertility rate in a given culture is 2.1 children per woman or higher, then that culture is default alive. But if it's below 2.1 children per women—and it stays below that level—then that culture will eventually cease to exist: it is default dead.

Now, fertility rates are usually discussed in the context of nations. And, conveniently, nations are also a way you can define cultural boundaries. That is, we can speak of Japanese or French culture. So, we can look at the fertility rates of various countries to see if the cultures they embody are default alive or default dead:


A world map showing countries by fertility rate, according to The CIA World FactBook, 2015 estimates. Image by Supaman89 via Wikipedia, CC BY-SA 3.0.

Everything in blue has below replacement fertility rates. That covers basically all of North America and Europe, plus a sizable share of the developing world, including China, Russia, and Brazil. Essentially, the different cultures embodied by all of these countries are default dead. Now, China has over a billion people, so Chinese culture is not in danger of disappearing anytime soon. But there are lots of European countries with less than 10 million people, some of which already have shrinking populations.

National boundaries are not the only criteria by which a culture can be defined. Neighborhoods, cities, regions, political affiliations, religions, ethnic groups, and socio-economic classes all have their own unique cultures. And if you go digging, you can probably pull up fertility rates for many of these. I'll leave that to you, though, because what I really want to do here is get you to use this lens to look at your own culture.

So, think about the culture you identify with—whatever group you consider your people. This could be the culture of your country or religion, or it could be more specific than that: perhaps your people are well educated, secular and left-leaning, Or maybe they're working class religious fundamentalists. It doesn't matter; just whoever you think of as your people. Now take a look around. If the norm amongst your people is for most couples to have 2 or 3 children, with only a few having less than that, then your culture is probably default alive. But, if that's not the case, if, instead, most families in your culture have 1 or 2 children—or none at all—then your culture is default dead.

Now, the solution to the fertility issue which is usually put forward is immigration. At the national level, this means importing people from other countries. For cultures defined by criteria other than national boundaries—religions, socio-economic classes, political affiliations, etc.—this means recruiting people from outside of the culture. Immigration is a fine strategy, in general. And I am always happy to have more people think or believe like me. But immigration should never be the only strategy.

To return to our earlier talk of startups: a culture relying on immigration to make up for its fertility problem is like a startup borrowing money to make up for the fact that it isn't profitable. The problem is twofold: 1) neither strategy actually solves the underlying issue, and 2) both strategies are completely dependent on external circumstances to remain viable. In the same way that venture capitalists may decide to stop lending money to a startup, one day the rest of the world might not have any extra people for your culture to import.

And then what?

Now, I can't know what's going on in your head right now. But I can imagine there's a pretty good chance that you think I've been wagging a finger at you this whole time, condescending to you about how your culture is dying. But the truth is: I am pointing out that your culture is default dead because it is a convenient way for me to make a point. You see, if you are reading this, there's a pretty good chance that your culture is my culture. And my culture is default dead.

I look around at the kids I grew up and went to school with and very few of them have children. The same is true of the peers I am currently surrounded with. And yet they—we—are all getting to a point where having children is becoming a now-or-never kind of a thing. The story is the same in my family. Between my parents, there are 9 siblings. Those 9 siblings would need to have 17 children for their way of life to be default alive. But there are only 7 children in my generation.

Now, you might not think this whole default dead thing is a big deal. But I do. And, if you're at all concerned about how the future will play out—whether you care about climate change, civil rights, universal healthcare, space exploration, animal welfare, religious freedom, or gun rights—if you think that your worldview is correct and that more people should share it, then you should care about whether or not your people are having kids. Because the path taken on these issues will be largely determined by which culture has the most people. And if your culture isn't producing children, then how can it expect to have a say in the future?