Justice and false positives vs. false negatives

[nminusone]

False positives and false negatives exist in a trade-off balance. In almost any real-world situation the price for decreasing one is increasing the other. For instance the criminal justice system is not perfect. It allows some guilty people to go free (false negatives), and convicts some innocent people (false positives).

Poll The trade-off between false positives and false negativesAssume that the false

Comments

[heldc]

The phrasing on this is kind of odd, and made it difficult to conceptualize for me. My initial instinct was 1:1, because that seemed the fairest, but then I thought about it more, and decided 1:100 is actually a better ratio, but now I'm thinking about it more and questioning that. I dunno. It depends on time frames I guess?

[nminusone]

It may be a good thing that it's not as simple as just twisting a knob to set this trade-off. If it was I'd expect very large changes every time the White House (or whoever holds the knob) changes parties, and I don't think that'd be fair to the innocent or the guilty. I'd sure as hell hate to be the last innocent person convicted under a draconian system, the day before the doves took over and switched everything the other way.

[wotw]

Impossible to answer without more data than I have at my fingertips (though

[nminusone]

Yeah, it is somewhat unfair in that I don't think anybody in a position to make this sort of decision would be asked to do so without a lot more information. For a start I'd want to know the absolute rate of the crimes involved, and I'm sure a lot more facts and figures once I got to thinking about it.

[crouchback]

This is a good reference.

[nminusone]

An interesting summary!

I intentionally left out certain key information like the absolute crime rate and the justice system error rate (which isn't going to be changed that much by adjusting the balance between false positives and false negatives.) If the crime rate is 5% and (in an attempt to combat this) you imprison 10 innocents per one guilty, pretty soon half of the population is in jail. Likewise if the justice system has a 5% error rate (5% of the people who go through it are wrongfully convicted or acquitted) I would want a much higher N than if the system provably has a much lower error rate, say 0.1%. Personally I suspect the rate is between 1% and 5%, so I lean towards a higher N.

[crouchback]

I suspect the justice systems error rate is much higher-more in the range of between 10 and 15%.

[nminusone]

I'd really like to think it's lower but if someone presented me with hard evidence that it's 10% I don't think I'd be too surprised.