The figurative expressions “on the rise” and “on the increase” both mean increasing in frequency or intensity and are generally interchangeable in many contexts. We can both comfortably say “Violent crime is on the rise in the city” and “Violent crime is on the increase in the city.” However, when the context is that of improving or advancing in personal stature or of gaining some desirable trait, only “on the rise” is appropriate, as in “The family’s fortunes are on the rise” and in “That singer’s star is on the rise now that she has a new talent agent.” Semantically, “on the increase” doesn’t work in such contexts, as we can see in these awkward sounding sentences: “The family’s fortunes are on the increase.” “The singer’s star is on the increase now that she has a new talent agent.”
On closer examination, we will find that the choice between “on the rise” and “on the increase” primarily depends on the subject. When the subject is a numerically measurable quantity, as in the case of, say, “rice harvests” and “median incomes,” both “on the rise” and “on the increase” can be used:
“Rice harvests are on the rise in Isabela.” / “Rice harvests are on the increase in Isabela.”
“Median incomes are on the rise in farming towns.” /“Median incomes are on the increase in farming towns.”
When the subject is abstract and uncountable or not precisely measurable, however, very often only “on the rise” works semantically:
“Our luck is on the rise after a long, bad spell.” “Consumer confidence is on the rise after the prices of basic good stabilized.”
In the case of “on the increase” in such contexts, it becomes advisable to use its literal equivalent, “increasing,” instead:
“Our luck is increasing after a long, bad spell.” “Consumer confidence is increasing after the prices of basic good stabilized.”
