A very related difference is "Product Manager vs Project Manager". It may sound obvious to some, but I still encounter many people in the industry referring to Software Products as Software Projects, even though there are relevant ramifications when thinking in terms of Projects vs in term of Products.
It is strange, indeed. I have been reviewing what seems to be the original study: http://www.pewinternet.org/2018/05/31/teens-social-media-tec.... It includes some detailed figures about these disparities, but they don't seem to provide insights nor opinions on which reasons could be leading to those differences.
A wild guess here: assuming that there is a correlation between higher-income and higher-education groups (quite likely), it could be that more educated individuals are more informed about privacy issues, being more wary of their data. The lower Facebook usage find in both groups could be motivated by that (eg recent scandals, like Cambridge Analytica). This guess would explain lower Facebook usage among people with higher education (directly) and also among those with higher income (indirectly due to the assumed correlation with education). That's my two cents, although just a guess.
Great topic. Given the fact that we, developers (as humans), are terrible estimating in time tasks with a high degree of uncertainty (most cases in software development), the most effective way I have found after many years in the field is using velocity (based on effort points) as a (project-dependant) predictor, while applying Scrum, as described in the following article in detail:
I recently decided to dig into that discussion in my post: "Software Projects vs Software Products": https://www.romenrg.com/blog/2020/12/30/software-projects-vs...