The 'pension' group
These nouns refer to a particular source of income. This use is productive: noun groups referring to particular incomes are also used with this pattern, as in on \$370 a week and on £40,000 a year.
This would be a powerful encouragement to the unemployed to find a job instead of living on benefit.
At the beginning of last year I was on the dole for three months.
I think it most unfair that they intend to make my wife wait until age 67 before she can retire on a pension.
Earnings and income are always used with words that make the meaning more specific.
on benefit /benefits on income support on jobseeker's allowance on universal credit on welfare on the dole
Social security assistance is available for people on low incomes.
The following are used as normal count nouns.
earnings income pension