[E]veryone who is renting a house is renting it from someone who bought it, who is presumably not losing money on the deal. (Or is that a false presumption? Do landlords typically spend more to purchase and maintain their property than they make in rental income? How could that possibly be true?)

You can also ask a different question. If you borrow money to buy a house, you must find a lender willing to lend you at some interest rate. The interest rate is nothing but the price of renting money. So if it costs less to borrow (i.e. rent) the money to buy a house than to just rent the house directly, then how can the lender possibly be willing to lend you the money instead of investing it into a house himself and earning a rent higher than your interest?

When I make this argument, people usually try to argue that somehow you profit from buying by building equity with time. But if the money rent, i.e. interest, is equal to the house rent, then to build equity, you must make payments to the lender above this basic rent/interest rate -- otherwise you'll just keep renting the same amount of money indefinitely. And if you rent the house instead of making these higher payments, you can save and invest this difference, with the same positive effect on your net worth (which will also have an effect equivalent to the reduction in payments as the principal gets lower). Of course, this isn't true if the interest is lower than the rent, but then we get to the above question of why anyone would be so irrational as to lend at such terms. It also isn't true if the house price grows faster than any alternative investment -- but even ignoring the lessons from recent history, this again gets us to the question why someone would ever lend you the money at this cheap interest rate instead of investing the money himself into these fast-appreciating houses.

What these considerations show is that according to the textbook spherical-cow microeconomics, on a free market for housing, renting and buying should be equally good deals, since in efficient markets there is no possibility of arbitrage. And buying can be profitable over renting only if there is a strange opportunity for arbitrage where it's cheap to rent money but expensive to rent a house, even though money and houses are readily convertible into each other. A similar argument can of course be made against the possible advantage of renting -- except for the issues of risk-aversion and asset diversification, which decisively favor renting over owning.

In reality, of course, these simple spherical-cow models don't work, and there are lots of complicated and ill-understood factors involved, including all sorts of people's biases and signaling issues, high transaction costs, Knightian uncertainties, exuberant speculation, and not the least of all, huge government interference in the market by various subsidies, regulations, and other convoluted and dubious enterprises. The result is a complicated mess in which an accurate analysis of what's really going on is practically impossible, and in which there may indeed be possibilities for arbitrage.

However, regardless of all that, it seems to me that buying has some tremendous drawbacks, for which I can't see comparable upsides under any realistic circumstances. The first and foremost is that you're investing the bulk of your net worth (and on top of that a huge pile of borrowed money) into a single non-diversified asset, which seems like a crazy idea by the most basic principles of sound personal finance. [1] For various other drawbacks, one could perhaps argue that they are offset by the downsides of renting (though I would disagree), but this one really seems to me by itself like a decisive argument against getting into house ownership.

[1] Note that this is one possible solution to your landlord puzzle. The tenant may want to pay a premium to avoid placing most of his net worth into this asset because of risk-aversion, while for the (rich or corporate) landlord, it's just another item in a large portfolio with the risk well spread.

Showing 3 of 5 replies (Click to show all)

Here are some complicating factors:

The renter is paying the landlord to assume the risk of tenant mobility. That is, if the renter needs to move, they can do so and the landlord could be stuck with a vacant unit. On the other hand, someone who owns a home and needs to move, needs to find a buyer for the old place, and incurs material (~7%) transaction costs. People who want to stick around for a long time have no reason to pay a premium for an option they won't use, so longer-term residents tend to buy and not rent.

On the other hand, as long as they can ma... (read more)

4David_Allen8yBefore I bought my house I ran the numbers and came to the same conclusion, that home ownership would not maximize my net worth and would increase certain types of risk. As a result I see home ownership as a luxury, not as an investment. I bought my house because I wanted it as a luxury and believed I could manage the risk.
2Eliezer Yudkowsky8yIf mortgage interest is tax-deductible but rent isn't, then you have to pay higher rent in order for it to be converted into an interest payment that would come out of pretax income. I think this is how Michael Vassar said the market got so messed up, though I don't know if I'm correctly attributing it to him, or if the notion is unique to him (I expect not).

Review: Selfish Reasons to Have More Kids

by jsalvatier 3 min read29th May 2012260 comments


This is a review of Bryan Caplan’s book Selfish Reasons to Have More Kids. Co-written with Walid.


Adoption studies indicate that differences in parenting styles have mostly small impacts on long term life outcomes of children, such as happiness, income, intelligence, health, etc.. This means that parents can put less effort into parenting without hurting their children’s futures. If you think kids are neat, then you should consider having more. 


Note: We think this is a pretty useful book, and it has changed our minds on how many children we want to have, though neither one us has any children yet. Also, neither of us are experts on twin or adoption studies.

Caplan argues that parents drastically overestimate their ability to improve the adult lives of their children. His argument is driven by adoption studies, which suggest that there is very little that parents can do beyond techniques employed by the average parent that would get them better results with their children. Specifically, the following areas are identified as areas where differences in parenting don’t seem to matter:

  • No effect on life expectancy, overall health (as measured by the presence/absence of particular health problems and self reported health), height, weight or dental health.
  • No effect on intelligence.
  • No effect on various measures of personality: conscientiousness, agreeableness or openness (not certain about extroversion or neuroticism).
  • Little or no effect on marriage, marriage satisfaction, divorce, or child bearing.

But that is not to say that styles outside of the average do not matter at all -- there are a few areas where parenting differences do seem to have an effect:

  • A small effect on adult drinking, smoking and drug problems.
  • A small effect on educational attainment, but no effect on grades in school or on income.
  • A large effect on political and religious labels, such as whether you call yourself democrat or republican or Christian or Muslim but small effects on actual political and religious attitudes or behavior.
  • A moderate effect on when girls start having sex (but not boys), but no effect on teen pregnancy or adult sexual behaviors. 
  • Possibly a small effect on sexual orientation.
  • A moderate effect on how children remember and perceive their parents.

So how do adoption studies lead to these conclusions?

Adoption studies (If you have a link to a better overview or discussion of adoption studies, we'd appreciate it) help find out the influence of parenting differences on adult outcomes by comparing adoptees to their adopting family. If adoptees systematically tend to be more like their adopting family than like other adoptees along some measure (say religiosity or income), that implies that parenting differences affect that measure.

When an adoption study finds that parenting does not affect outcome X, it does not mean that parenting cannot affect it, just that the parenting styles in the data set did not affect it.

The evidence Caplan talks about is primarily long run life outcomes. Shorter run life outcomes often do show larger effects from parenting, but these effects diminish as the time horizon increases.

If parenting doesn’t matter, what does?

Caplan references twin studies in showing that genetics have relatively big effects on all the measures previously mentioned. This explains why we see strong correlations between parents’ traits and children's’ traits. He specifically uses it to call out attributes that we would commonly ascribe to parenting, but may actually have a much larger genetic component.


Once Caplan has argued for the stylized fact that parenting has only small effects on major life outcomes, he explores some of its implications. 

Don’t be a tiger parent

One big implication is that you should put less effort into trying to make your kids into great adults and more effort into making your and your kids’ lives more fun right now.

For example, parents probably spend too much energy convincing their children to eat their vegetables and learn the piano, given that it won’t affect whether they will eat healthy as adults or be more intelligent. No one likes fighting. If you want your kid to learn the violin so they’ll have fun right now, it may very well be worth it, but don’t do it because you think it will increase their future income or intelligence. If neither you nor your child likes doing an activity, consider whether you can stop doing it.

Adoption studies provide good evidence that most activities don’t have a much of a long term effect on your children, so you need good evidence to start thinking that an activity will be good for your kids future. The odds are against it.

Have more kids

Focusing more on making your and your children’s lives more fun means that overall, having kids should be more attractive. If having another kid no longer means fighting about finishing their broccoli every night, maybe it’s not such a bad idea. On the margin, you should consider having more kids. If you were planning to have zero kids, consider having one. If you were planning to have 3 kids, consider 4, etc.

Other Topics

In much of the rest of the book Caplan gives common sense advice for making parenting easier for the parents. A couple of these, such as the Ferber method for dealing with infant sleep problems, are empirically based.

Here are some other topics Caplan discusses in his book:

  • Happiness research on parenting. Caplan argues that although being a parent seems to make people less happy, the effect is small (Ch 1).
  • Child safety statistics. Children are many times safer than in decades past (Ch 4).
  • Many of the benefits of having children come later in life (e.g. having people who will come and visit you, etc.), which makes it psychologically easy to ignore these benefits (Ch 5).
  • The externalities of children. He argues that on net, extra people have large positive externalities (Ch 6), so you shouldn’t feel guilty for having more children.

What parts should I read?

We wholeheartedly recommend reading the first 5 chapters (121 pages) of Selfish Reasons To Have More Kids as these have the most useful parts of the book; the rest of the book is less valuable. 

Criticisms of Selfish Reason To Have More Kids

There are a number of criticisms relevant to Caplan’s arugments. For example:

  • Nisbett claims that heredity is much less important for IQ than thought (see also counterclaims posted below).
  • Will Wilkinson claims (one, two) that the cost of parenting plays a small role in people's family size decisions, thus it's not a very strong reason to have more kids.
  • Jason Collins likes the book but would like it to discuss the research on non-shared environment (i.e. that not explained by genetic or parenting differences, such as peer effects) (link).