Hi everyone,I am currently finishing a PhD in Biomed sciences in north carolina, USA.

The largest barrier for me personally has always been science behind  determining current and potential demand. 

Rent estimates are an art and a science.

Again, speaking to residential construction, it's not rocket science

This isn't rocket science, I am sure you're capable of understanding this. 

IT is more art than science and you will never know until it is to late.  

Per this NY Times article, the average American knows around 600 people.https://www.nytimes.com/2013/02/19/science/the-average-american-knows-how-many-people.html#:~:text=The%20average%20American%20knows%20about,do%20you%20know%20named%20Kevin%3FPer the US Census Bureau, the average American moves 11.7 time in their life, which based upon an approximate lifespan of 84 years, works out to be about every 7 years.https://www.census.gov/topics/population/migration/guidance/calculating-migration-expectancy.html#:~:text=Using%202007%20ACS%20data%2C%20it,one%20move%20per%20single%20yearSo, if the average American knows 600 people and they each move about every 7 years, that means that the average American knows around 85 people that move in any given year.How many of those moves do you want to be involved in?

Like most things it isn't rocket science but you need to know what your doing.

However, there is a lot of art over science.  

Perhaps if this was an investment in tech or life sciences where there is the possibility of an IPO you can generate this type of return but real estate does not yield these kinds of returns & anyone looking for these types of returns is investing in the wrong asset class. my current project which is about as good as we could do for 90 home project will turn out to be 2X in 3.5 years with return higher as principal came back starting in the first year and continue until built out.. when its all done I guess I might run it through a spread sheet to see what the IRR was.. 8 to 15X  is like you said a leverage stock type deal. not RE development