Why do low-income earners tend to spend more? I am reading an article in the Economist.
It is discussing the China's unbalanced economy especially the lower household consumption proportion in GDP than the global average. The writer thinks the poor social safety net in China plays a part in curbing the household consumption.
Then follows the below sentence.

As low-income earners have a higher propensity to spend, the lack of
support weighs on consumption more generally.

I don't quite understand why low-income earners have a higher tendency to consume.
I can't find any other supporting details in the article as if the writer takes it as a common sense.
Anybody could help to shed some light on it?
Thanks.
Marginal propensity to consume  is the proportion of an aggregate raise in pay that a consumer spends on the consumption of goods and services, as opposed to saving it. If someone gets extra income $\\\$1000$ and consumes  $\\\$750$ of this additional income their marginal propensity to consume is 0.75.
The marginal propensity to consume is higher for poor people since they have to devote higher share of an income to necessities. Suppose that person needs to spend at least $\\\$500$ a month for their living expenses. Now in such situation if a poor person would get a $\\\$500$ of income per month (relative to situation when the person would have nothing) they will have marginal propensity to consume 1 whether such person likes it or not as all additional income they get will be spend on these necessities. Person whose income would increase $\\\$1000$ (again relative to 0) will have to have at least marginal propensity to consume 0.5 and person with income increase of $\\\$10000$ (again relative to 0) at least marginal propensity 0.05. Of course, the richer people wont consume only necessities but the point is that as peoples incomes decrease the necessities become higher share of their budget.
At the same time as people get richer they spend a smaller proportion of their income as they already enjoy a high standard of living and thus are able to devote more of their income to savings.  You can read more about this in Blanchard et al Macroeconomics: a European perspective or any other macroeconomic textbook.