萨米 发表于 2015-7-15 14:02 
作为一个数据分析工作者，不得不承认那个分析的确是一个在现有信息下最好的估计方法。这个approach如果在ma ...
我也觉得数据不错，可惜解读的乱七八糟。这里一个归纳的比较好
What Phil Twyford has done is just a sleight-of-hand with percentages:
39.5% of house buyers are ethnically Chinese...
...but the resident Chinese population in Auckland is only 9%.
9% of residents can only buy 9% of houses...
...so 30.5% must be non-residents! Ta da!
Here are the same numbers, in absolute terms:
3,500 house buyers are ethnically Chinese...1
...but the resident Chinese population in Auckland is 126,0002.
126,000 residents can only buy 126,000 houses...
...so, uh, yeah.
It is entirely plausible that 126,000 people can buy 3,500 houses. He goes on to claim that: Mr Twyford said it was unlikely local Chinese — whom he did not wish to criticise — could be responsible for so many purchases, as they made up only 5 per cent of top income earners (those on more than $50,000 a year).
- First, Chinese migrants generally come with a lot of cash – because having a lot of cash is a criteria for immigrating to New Zealand. So they don’t need to have a high income to have enough cash to buy a house.
- Second, there are 293,103 people in Auckland earning more than $50k a year (Census 2013). 5% of that is 14,655 – no small group.
- Third, it makes no sense to assume that only those earning $50,000 a year can afford to buy a house, because only 26% of people in Auckland earn more than $50k, but 61.5% of homes are owner-occupied (both from Census 2013).
Once again, Twyford is using sleight-of-hand, comparing the 5% figure with 39.5%, as if you could rub two numbers together and they’ll transmute into something else. Twyford is doing this because all he has is “39.5% of last names in a list of house sales sound Chinese”. He wants it to mean “a lot of houses are bought by overseas Chinese”. But equally, it could mean that Chinese people in Auckland: - Are new migrants without a house
- Have more money
- Move more frequently
- More likely to be of household-forming age
- More likely to get help from their parents
- More likely to invest in real estate
There’s a long list of possibilities, but in the absence of evidence, that’s all they are: Possibilities. Wanting to believe in one doesn’t make it true. There are more problems with the list itself: - Is that one company where Labour got their leaked list from representative of the rest of the market?
- Is that one period (Feb-Apr) representive of the full year (are there seasonal effects)?
- Is that period comparable to previous years?
- If Chinese people are disproportionately engaged in speculation, are they disproportionately selling as well as buying (that’s how speculation works, right?)?
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发表于 2015-7-15 14:09:17
