Learn Turkish: Tahsilat düştüğü için gelir dağılımı bozulur. - Because collection falls, the income distribution deteriorates.

While düştüğü oranda means "to the extent that it falls" or "in proportion to its falling," this sentence uses için to indicate cause. The underlying grammar is exactly the same: verb + -dIk + possessive. Swapping için for oranda changes the meaning from "because it falls" to "in proportion to how much it falls."

Why is the aorist tense used in bozulur instead of the present continuous bozuluyor?

The aorist suffix -ur is used here because this statement expresses a general economic principle or a timeless truth. It means "whenever collection falls, income distribution deteriorates." If this were describing a specific, ongoing crisis, you would use the present continuous bozuluyor.

Why is it gelir dağılımı and not gelirin dağılımı?

Gelir dağılımı (income distribution) is an indefinite noun compound, meaning it refers to a general category. Only the second word takes the possessive suffix -ı. If you used the genitive case on the first word (gelirin dağılımı), it would mean "the distribution of the income," referring to a specific, previously mentioned pool of money.

Does tahsilat mean collection in the sense of a hobby?