As regular readers of this column know, I am very concerned about the low birth rates in modern countries. One of the contributing factors to low fertility is delayed marriage and child-birth. And one of the contributing factors to delayed marriage is the high cost of setting up an independent household. The biggest expenses for young people are taxes, student loans, and housing.

Even if you aren’t convinced, as I am, that below replacement fertility levels are a problem, there are more personal reasons to worry about it. Look at it this way: our bodies are physically ready to reproduce when we are in our teens. The average age of first menstruation is now 12.5, down from 16.2 in the nineteenth century. But the age at first marriage is 25.2. We aren’t ready for economic independence until our late twenties.

That means that we may have a gap of 10 to 15 years between the time we are biologically ready and the time we are economically ready. All those raging hormones are trying to get us to reproduce. That gap between the age at first menses and the age at first marriage creates, shall we say, a certain tension in society.

Right now, we manage that tension through contraception for the middle class and welfare for the poor.

Middle class teens are told that pre-marital sex is OK, as long as no pregnancy results. So we may have 10, 15, or maybe 20 years of sterile sex before we are ready to settle down, get married and have kids. We create habits during those years, habits of how we view sex, how we treat our partners, what we expect from our partners and from life in general.

These habits actively hinder our ability to build happy, life-long marriages. When we finally do want to have kids, we have to unlearn a lot of those habits.

Not to mention that delayed fertility often means reduced fertility. Many smart women who thought it was prudent to wait until their thirties to have kids, find to their dismay, that they are no longer able.

Wouldn't it be a good thing to make it economically feasible for people to get married during the peak fertility years of their early twenties? In previous generations, a couple of 18-year-olds could get married and make a go of it.

The constituency for housing regulations is existing homeowners. They typically favor regulations that increase the value of their homes. My husband and I live in Southern California. We own a home. Every time the housing market booms, our balance sheet improves. But those very same price increases make it less likely that our children will be able to live anywhere near us--unless they move in with us.

I don’t know about you, but I’m looking for a better way.

We can’t solve every problem of the demographic crisis. But we could do something about the high price of housing. We can lighten up on the historic preservation requirements and the environmental impact statements and the rest of the housing regulations. We shouldn’t artificially jack up the price of housing so high that thirty-somethings have to live with their parents.

See, the high cost of housing really does have something to do with sex and marriage and babies.