I'm so happy to see someone who has actually read some of these studies on here. There are only 2 reasons to do the translation behind peoples' backs AFAIK: 1

I'm so happy to see someone who has actually read some of these studies on here. There are only 2 reasons to do the translation behind peoples' backs AFAIK: 1) also from kahneman et al we know that humans are bad at estimating time, and much more consistent and accurate about measuring effort. And consistency is required for the law of large numbers to apply. By estimating in consistent non time units you avoid those cognitive biases. 2) humans will very quickly start to unconsciously bias the units if they feel pressure. Speaking in terms of time puts one very close to a lot of pressure points for a lot of people. Ideally engineers are concerned with doing things Right, and PMs are using past performance to predict how long that will take.