The US is also a major outlier among the places you mentioned, in that it's still breeding at above-replacement rates. I wonder if the difficulty of getting a house/car that can comfortably accommodate multiple children is a big factor.
I think that's primarily down to the US population being generally younger than most other western countries, and probably to an extent the average age of first marriage in the US, which is pretty much the lowest in the developed world. It's likely mostly the age profile thing, though, and the difference will diminish over time.
The US house size thing is, I suspect, more down to a combination of regulation and consumer preference. There may be some aspect of available land, but it's not the biggest factor; sparsely populated European countries, like Ireland, mostly have houses about the average European size.
The US generally has lighter regulation around energy efficiency, and to some extend fire safety and various other things, than most European countries for house building. This reduces the per-sqm cost of building, making big houses more feasible.
But US consumers also seem to prefer a large house (often a pointlessly large house; see the 3-5000sqft McMansions which have oddities like multiple dining rooms to use up the surplus space) with a very long commute to basically anything, where you're totally dependent on a car, whereas this is less popular in most European countries; they exist to some extent (especially in rural areas), but are less appealing.
Ultimately, you don't need a big house or car to have kids. In fact, Americans were having more kids back when their houses and cars were smaller. The big car, in particular, is a fairly modern invention; minivans have only really been a thing since the late 80s, and the SUV is a creature of the late 90s.
I've often thought about the large size of houses in the United States. I'm sure the reasons are complex and various, but here are some of the drivers of large and "cheaply built" homes. I don't say "cheaply" derogatorily, but as a comparison in cost of underlying materials. The vast majority of single-family residences in the US are made with wood (as apposed to masonry). Most homes in the US that appear to be made of masonry are done so with a veneer layer only.
- When a homeowner sells their primary residence, they are allowed a tax exemption of up to $250,000, or twice that amount if married. Since the 1960s, inflation-adjusted prices have been on the rise, which means the potential for a large tax-free gain when you sell.
- Housing in the United States are massively subsidized by tax policy. Mortgage interest is a deduction to income when filing federal income tax. This means that a dollar spent on a mortgage payment is worth more than a dollar spent on something such as a vacation, a car or other non-deductible purchase.
- Americans tend to move much more frequently than Europeans. An American will live in, on average, 2 or 3 times as many residences than a European [1]. As such, I think there is less "attachment" to a particular structure. Because people anticipate living in or owning a residence for less than 10 years, it seems that size is prioritized over durability.
- In the United States, the quality of public schools is highly correlated to the income of the surrounding area [2]. Most communities with higher income households are full of neighborhoods have covenants that require homes of a minimum size that are legally enforceable through homeowner associations. Not surprisingly, individuals with resources take measures to ensure that their neighbors are their economic peers. Parents are generally willing to sacrifice a lot to ensure high quality education for their children, which means they are willing to spend a large percentage of their income on housing (if that's what it takes to gain access to good schools).
Full disclosure: I am an American but have traveled extensively throughout the world and have often wondered what drives the size of homes in the US.
None of this, except arguably the durability thing, really impacts the size, though, only the price (and a lot of those big houses are quite cheap). As a European (Irish; average new build is about 90sqm), what puzzles me is what’s attractive about the size, especially when you get to 3000sqft and over. It just seems like a lot of space that most families would have little use for, which needs maintenance (and presumably costs a fortune to heat and cool).
The cost of utilities in the US are relatively cheap - especially compared to many places in Europe. The cost of electricity in Ireland, for example, is more than triple what I pay in my state [1].
This also applies to gasoline / petrol. Much cheaper in the USA which makes living father from work less of an issue, which means cheaper and bigger lots are a viable option for living. Big, inexpensive parcels of land allow for bigger homes.
When people are incentivized by the government to spend money in housing and when the cost of building materials used are relatively cheap, and the cost of living in a home is modest, I suppose the proliferation of larger homes is not surprising.
The US is no longer breeding at above-replacement; we're now just slightly below.
However, to quote from the link below: “Yes, it’s below replacement level, but not dramatically so,” Dr. Brady said. “We have a high level of influx of immigrants that compensates for it.”
This could, of course, change if Trump ever builds the wall. :)
Now that you mentioned it.. Since japan's birth rate is decreasing year by year, it does make sense that home prices naturally decrease/depreciate. Simply less demand.
