Bryan Caplan  

Optimizing Your Family Size in Real Time

Discrimination, Liberty, and t... Household Incomes Declined Dur...
Someone recently asked me, "How should you decide how many kids to have?"  Since he'd already read Selfish Reasons to Have More Kids, I thought he deserved a detailed step-by-step answer.  Here's roughly what I told him:

Having kids is very experiential.  "When they're your kids, it's different" is totally true.  Even if you spend a lot of time taking care of nephews and nieces, you could easily be surprised by what parenthood feels like.  The upshot: Even I think that it's crazy to say "I want ten kids" before you have any kids.

Fortunately, people rarely have to suddenly decide between having zero kids or ten kids.  The process usually unfolds one kid at a time.  (Two at a time for me my first time around, but multiples are still rare).  I therefore recommend the following rules for optimizing your family size in real time:

Step 1: After finding a spouse who closely psychologically resembles the kids you want to have, have one child.

Step 2: Use my Serenity Parenting techniques to make your experience as pleasant as you can reasonably expect.

Step 3: See how much you like being a parent of one kid - opportunity costs included.

Step 4: If you really don't enjoy being a parent despite using Serenity Parenting, wait and see if your experience improves. 

Step 5: If and when you decide you enjoy being a parent of one kid, have another.  Then return to Step 3 (replacing "parent of one kid" with "parent of one more kid").

Step 6: When you're on the fence, err on the side of having another kid.  A life well-lived includes achievement as well as happiness.  Creating and raising one more child is a great achievement, even your last child makes you marginally less happy.

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COMMENTS (28 to date)
Charlie writes:

Something tells me you meant to say, "even if your last child makes you marginally less happy."

George writes:

My wife and I had 4 kids between us when number 5 came along in our 44th year. We'll be parenting until he goes to college when we're 62.

To my everlasting surprise, raising 5 kids has felt like the best decision we ever could have made. For those people who think that each child is simply more of a burden, you will receive more joy and happiness than you can imagine.

Of course, 6 kids is lunacy.

Tracy W writes:

Just to let you know we're thinking of number 2!

Any ideas on how to get one's husband to stop worrying so much about safety though?

Mr Caplan,

I believe you are wrong. You, like me, started out by having two children. This masked the work required by just one child. Parents with one child always look at us like we are crazy “boy do you have your hands full”, when in reality our boys play with each other, entertain each other, and request less of our time. Even if you think that one child does not require as much attention, that child might not agree. Now with four children we are seeing the sibling effect even stronger. Starting with one child “to see what it is like” is probably not the right measure. Having two children close in age should be step one.


Trespassers W writes:
Any ideas on how to get one's husband to stop worrying so much about safety though?

Try reading Free-Range Kids (the book, then the blog). It certainly changed my perspective as a parent.

RPLong writes:

Prof. Caplan -

I would love to read about how you instill your children with a sense of morality. Have you written about this before? You make a compelling case for your parenting style, but from what I've read, you have written a lot about morality, and a lot about raising children - but not so much about raising children with a sense of morality.

Call it a request. :)

Brian Shelley writes:

Funny that this was my advice to my wife early in our marriage. She wanted four, but I wanted to take an incremental approach. We now have four, and have experienced the diminishing marginal effort with each addition. At this vantage, four more sounds far easier than when I had zero.

Finch writes:

Any idea whether the bias described above also applies to happiness research concerning children?

Also, to echo RPLong, having twins is a great way to realize that regular parenting just isn't that hard.

Finally, I generally like your method and think people way overestimate the downsides of kids, but can you address common questions like these?:
(1) "I'm getting older and worried about a birth defect." (i.e., I'm worried the previous good experiences will not be representative of this one), and;
(2) "How am I going to pay for college?" (i.e., I agree these kids are great now, but there are deferred costs that I'm not seeing yet).

Ken B writes:

Sometimes it's better to rent not buy. Of course the issue is confounded by the pleasure of the shopping.

My aunt did rent-to-own. She adopted one. Then fostered one who didn't take. Then another. But that second was from a family of 7 who were orphaned. So then they adopted all, making 8 adoptees. Not sure this fits Bryan's recommended plan ...

And thus was formed a living Bob Newhart joke: "This is my brother Pete, and this is my other brother Pete."

Tracy W writes:

RPLong: Caplan has implicitly written about raising children with morality.
Your kids basically get their morality from 3 places:
1) Their genes - so pick your spouse wisely
2) Their peers - so pick where you live based on the sort of kids they'll be associating with
3) Their free choices - out of your hands.

If you look at changes in attitudes to matters like homosexuality and racism in the last few decades, it's clear that children don't simply learn their sense of morality from their parents.

Tracy W writes:

Trespassers W - any ideas on getting husband to read the book?
(I'm currently a widow, I got him to watch one episode of Avator The Last Airbender as a favour to me, and now he's watching them non-stop).

Finch writes:

> Also, to echo RPLong, having twins is a great way
> to realize that regular parenting just isn't that
> hard.

Cristopher C Fischer said something to that effect, not RPLong. Apologies to both for the incorrect attribution.

ThomasL writes:


(1) Is logically impossible. Something cannot give what it does not have. Genes are chemical combinations, not rational animals. They are completely amoral, not in any negative sense, but in the same way as a plant or a chair are amoral.

Morality cannot spring from amorality. There is no possible combination by which amoral elements suddenly erupt as moral agents.

Were it possible (though it's not), strictly speaking it would no longer be morality at all, because morality entails responsibility of action. No person can be said to be responsible for their genetic code as such, either positively or negatively, so were morality shifted into the sphere of non-responsibility, it could no longer be called morality.

I do not deny that picking a spouse is critical, just not because of "genetic morality inheritance".

Thomas Boyle writes:


"Something cannot give what it does not have."

I beg to differ. The above sentence is just a string of characters, devoid of any meaning.

Except that it's not.

Genes influence thought patterns - and where does morality arise, if not there?

"Influence" is not the same as "determine absolutely" - and there is your responsibility.

And, yes, morality can indeed arise from amorality - a lesson game theorists discovered years ago. Their discovery - do unto others as you would wish them to do unto you, and also do unto others as they have done unto you (but be somewhat forgiving) - turns out to be quite similar to the core of moral advice from many traditions. Those who cooperate, but stand up for themselves, thrive, and have more descendants. If you're religious, God simply found a way to reward morality on earth. If not, it's just an emergent phenomenon.

And, closing the loop, emergent phenomena can be described as "something giving what (its component parts) did not have".

Ken B writes:

@ThomasL: Likewise 2 is logically impossible. Peers are just walking blobs of meat, bags of chemicals, and as you note, chemicals are amoral. Why you can no more expect genes to influence behavior than you can expect them recipes to influence cooking.

ThomasL writes:


No, it is not meaningless squiggles. The characters themselves are the creation of mind, meant to convey language (the creation of many minds). I arranged those characters into words (themselves creations of other minds) to convey the meaning I had in mind already. That sentence is the effect of my mind, and the minds which preceded and assisted me. Its meaning does not spring out of the meaningless squiggles themselves, it is impressed on the squiggles. The cause (those minds) are greater than the effect (the squiggles).

"Nothing can give what it does not have" is a vernacular way of saying, "No effect can be greater than the sum of all its causes."

The effect here, that sentence, is quite definitely less than the sum of its causes, and so is perfectly consistent.

Now, if I threw a bunch of chalk at a chalkboard and asked you to read it, you would (I hope) reasonably object that the great effect of language cannot arise from the feeble cause of random chalk squiggles--and you would be correct.


You are correct if a person is merely an arrangement of chemicals. I do not believe that; but if you do, I would be interested if you could provide your argument for how a binding morality arises from it.

And then an argument why I should trust your argument, proceeding as it is from a random mixture of chemicals that strangely sounds like it is talking...

MingoV writes:

I have no disagreements with the six steps. However, Steps 3 and 4 must be abbreviated when woman marry after age 30 because of increased risks of pregnancy complications and fetal chromosomal defects.* Thus, a couple may find that they enjoy their first infant, opt for a second child, and then discover that they hate dealing with a toddler.

*Obviously, adoption is a way to avoid those problems, but most couples have those selfish genes that want to propagate.

Tracy W writes:

ThomasL: Your line of argument strikes me as illogical and unempirical.

We have brains, which permit us to make moral decisions - people who have lost a body part such as a leg or a kidney still make moral decisions, people who have literately lost their heads don't.
Genes contain the information to build brains - rocks do not develop morality no matter how much parenting you lavish on them.

Therefore morality springs from genes (and environment - babies need food and oxygen and water and love as well as genes). It is perfectly possible to create something you don't have, indeed that's the very definition of creation. And once you've created something you can give it.

No effect can be greater than the sum of all its causes.

On the contrary, numerous effects are greater than the sum of all their causes. For example, the sum of 5 and 6 is 11, but the product of 5 and 6 is 30.

Ken B writes:

@ThomasL: I think morality developed the same way language, love, desire, anger, hatred, fear, blue eyes, and musicality did. It evolved. Can you provide a counter example perhaps? A non-evolved entity with morals? or even one with language, love, desire and fear?

Ken B writes:

"You are correct if a person is merely an arrangement of chemicals. I do not believe that;"

This is subtly but importantly different from my reductio. In my reduction I said *bag* of chemicals. An *arrangement* has structure and carries information. Like DNA does. But you were denying the importance of that structure and information in your argument, so I carefully left it out of my reductio.

A bag of chemicals is unlikely to be sentient, but we know quite well that some arrangements are.

Finch writes:

I may be misunderstanding him, but I took ThomasL to mean that a "binding" morality had to come from something more than the thoughts and feelings of people, like say a god. I.e., that people may have opinions about this stuff, but they aren't really binding. "You are correct if a person is merely an arrangement of chemicals. I do not believe that;" - that sounds vaguely religious. So people might have evolved a morality, but that's just chemicals and genes and such, and therefore doesn't really count.

On topic, I wonder how a welfare-receiving single mom might apply Bryan's six steps? I don't see anything in there that would obviously turn her off from having more kids at any point. There's no "consider your impact on people outside you family" step, for example.

ThomasL writes:

Finch is correct. By "binding" I mean that if, morality is instituted by man, created by him, and so owing its existence to him, there is no reason it cannot be changed by him. If it can be changed by him, there is no way to say that it "binds" him.

Since one is not objectively bound to an objective moral order, one is only "bound" prudentially by the costs likely to be incurred if one does not comply with the dictates of the many.

Morality then is, as Thrasymachus described it, "nothing other than the advantage of the stronger.”

Ken B writes:
I mean that if, morality is instituted by man, created by him, and so owing its existence to him
I don't think anyone here is arguing that. It's very different to say it emerges from the nature of man than to say it emerges from the caprice of man.
thomas boyle writes:


You say, "if morality is instituted by man, created by him, and so owing its existence to him, there is no reason it cannot be changed by him"

On this, we agree. I suspect, however, that we would differ on what it means.

A secularist views this statement as a test of whether a particular moral rule is fundamental, or is arbitrary. For example, a prohibition on wearing clothing made from more than one fabric, would be arbitrary. On the other hand, a prohibition on stealing is not arbitrary: every society has one, and for good (practical, universally applicable) reason. You cannot create successful societies in which stealing is widespread and tolerated (although you can create short-lived, unsuccessful ones). The prohibition on stealing is "binding"; the prohibition on mixed fabrics is arbitrary and, if such a moral rule is created by man, it can be reversed by man.

A religious person, on the other hand, could view both prohibitions as equally binding, because they are handed down by a higher authority. I think this is what you mean by a "binding" morality.

ThomasL writes:


Fairly put. But we have wandered into a Natural Law dimension which is not easily addressed from the initial comment that morality is "inherited" except in the broadest of senses that all men share a common nature or substance, a "human nature," which entails morality.

That is, that morality is essentially part of what it means to be a human.

That is somewhat different than saying we inherit morality in the sense TracyW used it as a specific inheritable genetic trait, like blue eyes or dark hair, so that one potential spouse's genes had more "morality" in them than another, and one should choose accordingly. Barring something truly contrary to Natural Law, any potential spouse is human, and so provides the same essential human nature.

Where you and I may still differ, is that morality expressed as Natural Law is either (1) a product of will or (2) not a product of will. If it is willed, it is either willed by man or by something higher than man. If it is willed by man, he can choose to will something else (see previous post). It is one of man's distinguishing features to will as and what he chooses. If it is not a product of will, it is not a true constraint on the will, because morality is precisely a constraint on man telling him what he ought to will (and proceeding from the will, act). Nature producing human beings that have blue eyes is not the same thing as Natural Law telling a human being that it is wrong to harm another human being. One describes what *is* (and further, what is possible and what impossible), the other of what *ought* to be (what is right and wrong). There is nothing less than some absolutely unchanging Will that can make that transition from the description of what is to what ought to be in a manner that is binding on all wills, so that they *ought* not--and cannot, with validity--will something else.

The product of chance and randomness, even ordered by emergent phenomenon, is insufficient to "bind" a man's will by telling him that some things are proper objects of his will and others improper; it only tells him what he can do and what he can't do--like Jack Sparrow. :)

ThomasL writes:


But why should I care if society is successful or unsuccessful? If we both accept that happiness is an end that is sought for its own sake, so that a "successful" society might be understood as one producing more happiness for more people than an "unsuccessful" society would do, you have succeeded in pointing out that one arrangement of society can be better at producing happiness than another.

It does not, however, confer any particular moral obligation on me to respect that. If stealing pleases me, even if it would tend to make my society less "successful" by the above terms, I don't see why I should feel morally oblight to subordinate my happiness to the general happiness, unless it is something that I *ought* to do out of some preexisting moral obligation, or I am simply afraid of what my society will do to me if I do not comply with their rules.

In either case we are off the text of reason's judgment of what is more or less successful, and back into the language of moral obligation per se, or of the advantage of the strong over the weak.

Tracy W writes:


By "binding" I mean that if, morality is instituted by man, created by him, and so owing its existence to him, there is no reason it cannot be changed by him.

This is false. Firstly, women have a hand in morality too. Sojourner Truth and Mary Wollenstonecraft, to give just two examples, were moral thinkers as much as any man.

Secondly, your implicit proposition that if someone creates something then they have a free range to change it however they like, is empirically wrong. For example, I created a baby boy, said baby owes its existence to me (and my husband), but even though I created him, my ability to change him is limited, to pick one trait while there are plenty of things I could do to make him stupider, I can't make him an genius. Another trait: I can't make him a baby girl, instead of a baby boy. Creation does not mean an unlimited ability to change something. Nor does a man have an unlimited ability to change his baby. The ability of my parents to change me, as a full-grown adult, is even more limited even though they created me. Thus your assertion is empirically false, even when read as being about humans, not just men.

Thirdly, this is irrelevant as to whether our morality is determined in part by our genes, which was your initial argument. Wherever a sense of morality comes from, something needs a brain in order to have a sense of morality, rocks are amoral. And genes are a vital part (not the only vital part, but a vital part) of how us animals construct brains.

Again, your line of argument strikes me as illogical and unempirical.

That is somewhat different than saying we inherit morality in the sense TracyW used it as a specific inheritable genetic trait, like blue eyes or dark hair,

Again you are being unempirical, I did not use morality in the sense you attribute to me. I said that one's morality came from a combination of 3 factors: one's genes, one's peers and one's free choices. While a person can change their eye colour (with contacts) or their hair colour (with bleaches and dyes), that's very different to the manner in which we pick up our moral understanding from our peers: I don't need outside props to start behaving in a more moral manner. Furthermore, morality is far more complex than blue eyes or dark hair, as I hope you are aware, so it's not a specific inheritable trait - one can't sum up morality like one can sum up eye or hair colour.

Logic is all very good in its way, but it's dependent on the quality of the propositions. If you start from incorrect starting points (eg "No effect can be greater than the sum of all its causes", "morality [is] a specific inheritable genetic trait, like blue eyes or dark hair", or your implicit assertion that if something is created then ) you will only arrive at accurate conclusions by pure chance.

Tracy W writes:

Sorry, last parenthesis in my previous comment was incomplete, it should read "...your implicit assertion that if something is created then it can be changed by the creator)"

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