Repair modifier

The Repair modifier increases the rate at which your damaged units repair (or increase their strength).

Please note that the repair rate of damaged province structures (e.g. infrastructure, industry, resource gathering) are not affected by this modifier, nor are they intended for it to be.

This information is correct as of the HoI2 1.3b patch.

Discussion of the testing done to establish this can be found on the last pages of this thread: