In the Unity editor, the lowest available Android version for debugging is Android 2.3.1 In my case, I have a phone running an older version of Android and I intend to publish my game to a wide audience. With the lowest version being 2.3.1, I see a problem publishing my games to older smartphones which still occupy a considerable size of the market share. My question is: Is there a way to publish my game to older versions of Android? Or is it impossible?
Versions later than Unity 4.2.x don't support Android versions earlier than 2.3.x. So if your project relies on functionality only present in 4.3.x and higher, you're out of luck.
Otherwise you can still download a 4.2.x or earlier version of Unity and create your builds with that.