Demographics should be looked at.

Although I don't know much about the NYC real estate market, when I was deciding where to move to from Chicago to build my rental portfolio in my backyard and start my real estate career, these where demographic data I was looking at. 

You are incorrect in regards the demographic changes taking place in Chicago.  

My question is do the changing demographics impact the rental rates?

Schools, downtowns, hospitals etc.Can you figure out what the prevalent demographic is in your area, seniors, millennials, students or iron workers, cater to the market. 

A central AC unit is one of the more expensive items to replace and repair....if the climate in your area, plus the demographics renting your property, allow you to get away with it, then there are advantages to putting the responsibility on your tenant to buy and install a window unit, and you already said they pay for electricity.

I understand that purchase and rental prices may go up or down over the next several years depending on demographic influences across the nation. 

It’s basically an easy way to organize information to determine demographics and what types of rentals to purchase.

You can pick one up for under $15,000, and they appeal to a certain demographics. 

Demographics are important but there is a lot more to consider.