Affordability is whether a household can carry a payment out of its income. For housing it is usually measured as the share of monthly income taken by the mortgage, or the ratio of home prices to incomes.
可负担性指家庭能否用收入承担一笔支出。对住房来说，通常用月供占收入的比例，或房价收入比来衡量。
Affordability is the constraint that eventually stops a price rally. Prices can rise faster than incomes for a while, but only while credit is cheap or buyers expect further gains. When the monthly payment takes 40% of income, the marginal buyer disappears, and volume falls before prices do — which is why transaction counts are a better early signal than prices.
可负担性是最终会让价格上涨停下来的一道约束。房价可以在一段时间里跑得比收入快，但前提是信贷便宜，或买家预期还会涨。
当月供占到收入的 40%，边际买家就消失了。成交量会先于价格下跌——所以成交量比价格是更好的早期信号。
| Move变动 | Where it appeared出现位置 | What it means这句话在说什么 |
|---|---|---|
| 3.0% | US pending home sales fall to a 12-year low as mortgage rates top 7% 「买得起」的程度 · 第 3 张术语卡 | The median US sale price is $393,895 and wages are up 3.0% a year — below inflation. That is why four in ten of the deals written in September were torn up or, in the end, never happened at all. 判断可负担性别只看房价，要看「月供 / 收入」这个比值。房价涨 10% 和利率涨 1 个百分点，对月供的影响可以一样大。举例：40 万美元的房子，30 年期利率从 6% 升到 7.4%，月供大约多 350–380 美元，一年就多 4,300 美元上下 —— 对年收入 8 万美元的家庭，等于凭空吃掉 5% 以上的可支配收入。这就是为什么利率一破 7%，需求断崖式下滑。 |
| — | PepsiCo to raise some prices after cuts failed to grow sales 「买得起」的程度 · 第 1 张术语卡 | PepsiCo pledged in February to make its snacks more affordable — and is now taking part of that back. 零售业谈 affordability，常常同时看三件事：绝对价格（一袋多少钱）、单位价格（每 100 克多少钱）、占收入比例。企业降价的目的一般有两个：抢回销量，或者抢回货架位。百事 2 月两样都想要——降价的同时还谈下了「双位数增长的货架位」；但几个月后销量没起来，只好把价格往回提。判断一个降价动作成功与否，别看价格，看销量。 |
Affordability is the same as price
It is price relative to income and rates.
Falling prices fix affordability
Rates matter as much: a 2-point rise can offset a 15% price cut.
It only matters for housing
Food, healthcare and transport have the same arithmetic.
· housing affordability
· affordability ratio
· stretched buyers
· payment shock
· price-to-income
housing affordability 住房可负担性；affordability ratio 可负担比率；stretched buyers 捉襟见肘的买家；payment shock 月供冲击；price-to-income 房价收入比。
· affordability vs affordability index
· price vs monthly payment
affordability 是负担能力，affordability index 是把它量化成指数；price 是总价，monthly payment 是月供。
Homes are now less affordable than at any point since X, with payments at Y% of income.
数据句：住房现在是 X 以来最不可负担的，月供占收入 Y%——at any point since 是「自……以来最」。
“The median US sale price is $393,895 and wages are up 3.0% a year — below inflation. That is why four in ten…”
“PepsiCo pledged in February to make its snacks more affordable — and is now taking part of that back.”