Across the game types in Rocket League, a different ball is used. In Hoops, the ball takes on the appearance of a basketball, which makes sense. Is this ball bouncier than, say, the normal ball found in Chaos or Standard matches? It seems like it bounces a little bit more since it's a basketball.
No, the balls are the same in Hoops and Soccar. User MegaChip97 did some testing to prove this:
Open up a private game. Drive to the ball until you stand directly infront of it. Backflip once. Boost into the ball.
DO the same thing on Hoops private.
From my experience playing and the test it behaves exactly the same.
You can also airdribble with it which I doubt I would be able to do if it would be any different from the normal ball.
If you want to test the bounciness, just do the same setup and look at its bounces.
As an aside, while searching for a definitive answer, I came across many instances where users admitted that the different shape of the court and the walls definitely may be tricking people into thinking the ball itself behaves differently, when really it's the arena that's different.