Is there any data backing up the idea that it actually is a disincentive?
1. Anyone I know that has received benefits for being unemployed desperately wants to be employed again.
2. In the UK, unless things have changed, you can work up to 16 hours per week while receiving unemployment benefits and I believe the benefits you receive gradually falls with the amount of work you get paid for.
3. If you suddenly lose your job benefits aren't built so that you can maintain your current life style. You likely have car, insurance, and mortgage payments to make and the benefits you're receiving either just get you by or you have to renegotiate some of that debt. Not a situation you want to be in long-term.