Thanks for a comprehensive reply, and I apologise for not seeing it earlier. To frame what follows, my perspective is that of someone who spends a lot of time l

Thanks for a comprehensive reply, and I apologise for not seeing it earlier. To frame what follows, my perspective is that of someone who spends a lot of time learning about and using these kinds of techniques. You seem to appreciate the problems with potential biases, and your point about data collection is well taken, though I would note it doesn't require application of algorithmic sentencing. I would, however, urge you to continue to think about the difficulty of automating the sentencing decisions made by a human, from a mathematical perspective - the problem amounts to performing factor analysis by simply throwing away a large number of factors that are difficult to measure. It is not clear to me that that method will be able to capture those difficult parts of the distribution that people intuitively refer to as justice. I also urge you to continue to think about the difficulty of optimising that automated sentencing procedure, which requires you to select parameters to optimise for. This problem faces similar difficulties - whereas a human might update their judgment on a wide range of observations (potentially including everything they experience), for an automated procedure we typically have to choose a handful of parameters based on some expert intuition about what is important. The choice of those parameters can be critical, and can expose feedbacks that would be naturally corrected by humans. The previous two points are often dismissed as merely being difficult challenges, rather than fundamental problems with the techniques, and, whilst I am inclined to agree with that perspective, they are difficult challenges, and the decisions that such systems end up making can (and often do, in my experience) have consequences that weren't expected. This leads to my political reason for being cautious about these systems, which is motivated precisely by the fact that they can be cheaper, at least when one is only making a comparison based on decisions per dollar, or something along those lines. I am happy for these systems to be used by informed practitioners as a mechanical aid to their decision making, but cost savings are such an evergreen issue that I fear pressures to dispense with the human and "make do" with the automated system will become too strong to bear (for the politicians, not the lawyers). Ultimately one can imagine a system that is constantly improved over time (an expensive prospect) could result in more objective sentencing - my concerns are that uncaring politicians will exploit the availability of the techniques to cut costs, and that once those costs are cut it will be difficult to justify the (relatively) increased expenditures necessary to fund improvements. I don't have your insider's perspective, but I suppose overall I struggle to accept that saving costs in this way is one of the most necessary reforms to the American justice system.