There are certain factors which influence the expenditure patterns of people from different income groups. For this topic it is good to read the previous topic: Changes in an individual’s earnings over time
When we read that topic we come to know that lifetime earnings and lifetime investment income affects the income patterns of most of the people. We also know that income fluctuates under unexpected circumstances as well.
Here is also a good article to read on this topic:
Changing Spending Patterns
From month-to-month and year-to-year, consumer spending is a great constant in the economy. But seen over a longer period of time, changing prices and developing opportunities cause dramatic shifts in consumer spending.
In broad terms, there has been little change in the share of consumer spending claimed by durable goods in the period 1947 to 2000 >> Read the full article.