Incentive for Daughter to Quit Drinking

Thank you for your question. While incentive programs have been known to be effective with alcoholics and addicts, the incentives have always been small. I think using a plan like you devised could back fire on you. Think about what you are teaching her. By getting money for staying sober, she would be externally motivated to sobriety. When you remove the external motivation at the end of twenty months, what would motivate her then? Alcoholics or addicts that find internal motivation seem more likely to continue sobriety because the motivation comes from within. It's something that they can always access, anytime they want. But when you are motivated by something external, when the external motivation is removed, what do you have to fall back on?

It also seems to me that this would be teaching her that money is a reward. It teaches her that money is more important than internal mechanisms for change. It teaches her to place more value on things, what she can get in life and material possessions. In my experience, the happiest people are the ones who don't care much about money and place higher value on being a good person, caring for others, loving themselves and other things that once again are internal not external. 

There's also the chance that she could agree to your plan just for the money and still find a way to "cheat." You may be monitoring her for alcohol but she could end up turning to drugs. Even if you drug test her, there are plenty of drugs that don't show up on drug tests. Addicts are very sneaky and will find a way to get the "high" they want no matter what you do. I worked in a methadone clinic for years. There were lots of clients that you could clearly see were intoxicated but they passed drug tests so I know there are ways around any test out there.

I commend you for trying to help your daughter but I don't think this is the way to go about it. I think she would be better off in a treatment program. There are lots of treatment programs out there that don't cost anything too. I think a commitment to long term treatment is the best option for anyone struggling with addiction.