I'm more wondering why each data point is 1 year and 1 month ahead.

Ahh yes, you did say X axis. I can't help with that.

Automatic spacing by Excel, perhaps?

Ah, thanks HM. I think you're on to it.

Saw this over on FB. I thought it was an interesting thing to graph.
Doesn't this mostly just show that nobody has any money to spend right now? (And houses still cost a lot.)
Attachment 44193

How can a house cost 8 times disposable income, when there's no disposable income?
2 X 0 = 0
8 X 0 = 0

I think empty cardboard boxes are still free, so that would fit with your equation.

I've been following a debate for years, about whether Australian houses are over-valued. New house price to median income ratios often come up, but we need to be clear whether this is median individual income or median household income.

With the rise in two-income families, house prices were able to rise much faster than individual incomes. *Most* of this second income has gone to servicing the mortgage payments.

In other words, some say, generation X was forced to send the missus out to work to pay the enormous mortgage to cover the cost of the inflated house prices that are funding the retirement of the baby boomers, at the expense of the personal and social health of all involved.

I was just looking at individual 1940 census information for my neighborhood to learn a little about the local history, and the thing that jumped out at me was that housing values were about double the annual income at the time. My grandfather's 1940 census showed he made in a year what his house was worth. That amazed me. I would LOVE to make in a year what our house is worth. He had his own business and was wealthier than his neighbors, but still.

As I remember it since 1960...
In your g-fathers day, he dealt directly with the bank that loaned
the money and held the mortage.

The WWII vets had a major impact on the US, and in many ways.
One way was the creation of the FHA (Federal Housing Authority).
which became the way people had prospective houses inspected,
evaluated, and if it qualified, mortaged (at rates up to 3%)

The Buyer's income was evaluated, and at first only the man's salary was considered.
The rationale was that the woman might get pregnant and so any income she earned would end.

As the 60's and the women's movement came along, the change
was made to include the woman's income was included. Of course,
this made it possible for couples to get into a higher priced house, and the $ inflation started.

By the late 60's the mortage rates were going up too.
We bought our first house for $18k at the last of the 3% mortgages.
My annual income was just about 50% of that.

Our first house was about twice Mr. Clod's salary at the time, even though I was gainfully employed as well. We had been looking in a higher range at first, but someone gave us a financial book that advised to only ever buy a house based on one person's salary--not just in case of pregnancy, but also in case one or the other spouse got laid off. They had compelling mathematical examples of how quickly you could lose your house if you really went in for all you could possibly afford, and it changed our attitude a lot.

What was the name of that book?

It was The Complete Financial Guide for Young Couples, by Larry Burkett. It's technically a Christian book (being given to us by my mother-in-law, it would have to be,) but all that really means is that about every 10 pages or so there's a Bible passage to point out, "And hey! Everything I'm saying is Biblical too!" It's pretty easy to tune out. The guy is a professional financial advisor and has written several books on it. We got one of his teen books for my stepdaughter to work through this summer.

the x-axis is on a twenty five month scale. if you have many hundreds of data points, a grouping of twenty-five is reasonable. it does feel weird because we don't usually group months in bundles like that, unlike many other things.