national income

National income, by itself, doesn't tell us very much about the standard of living in a country.
The national income of India exceeds that of Canada but no on would claim that India was a better place to live for the typical member of the population. India's is higher simply because the population is 1.2 billion, there is enormous public-sector spending and high inward investment because of high interest rates and so on.

What is more important is national income per head of the population.
That measures the availability of goods and services per person.
On that basis, Canada is about 16th in the world economy with a figure of $40,000 per head; India is 126th with a figure of about $4000 per head; one-tenth of the Canadian.

Does this difference matter?
Yes, because it correlates very closely with many aspects of human existence:

- infant survival rises with national income per head
- the general level of healthiness in the population, also rises
- typical/average food intake per day, also
- educational attainment, also
- medical and health provision for the population, also
- average age at death, also
- amount of free time people get to enjoy life instead of just working, also
- public safety, security, and crime detection rates, also
- and so on.
Get the idea?

All these are low in economies with low national-income-per-head.
So national income does measure something about the economic conditions of human life.

But it is not a perfect measure. Rich countries are often not happier places to live; with depression and other mental illnesses, high levels of metabolic disease such as diabetes, and also serious dissatisfaction among young people who expect to get richer and richer..
Quite often poor communities, with low national income per head, are more peaceful places to live and bring up a family. With lower expectations, of course.