Over the same period, a million-dollar property decreased by 10%.The error is combining sales data for $300,000 and $1,000,000 properties and taking an average.

My guess is there is a limit on how much the taxes can increase/decrease each year to help homeowners plan. 

In the 1990s major cities began cleaning up their act by increasing effective police presence, aided by things like active cameras and debit cards, all leading to a decrease in violent crime.

This week Freddie Mac announced that the Homepossible minimum down payment requirement is decreasing from 15% down to 5%. 

The only time decreased equity hits you in the wallet is if you want or need to sell.

As the mortgage loan is paid down, the amount of income subject to UBIT decreases accordingly.  

I'm also considering Harrisburg but the property values have seemed to decrease over the last few years.

I just checked on Census Bureau and it says that the population is decreasing.

I am thinking something like 80% of rent, then 75%, 70% decreasing by 5% every rate renewal until we hit the price agreed upon. 

You'll notice if you do a conventional mortgage and pay a much higher sum than the minimum, the amount of interest you're paying each month decreases as well.