Housing Value Data in Houston

I've spent the better part of the last year analyzing the last 16 years of data from what HCAD publishes and finding trends that my economics training wants to see. I get the argument that property tax data isn't what the house will sell for, but it's a huge repository of data so I want to use it.

For example, I found that single family homes within a half mile of one of the new MetroRAIL stations command a premium in value per square foot of the home of $15.20. i.e. a 2000 square foot home would cost you $30,400 more simply because it is located within a half mile of an operational transit station. It's obvious there are a more nuanced arguments including other variables, but I'm using the data that is available and not trying to change it much.

That helped me to conclude that Harris County and Houston receive an additional $6 million in property tax revenue per year based on the total square footage of single family homes and multiplied by a 2.4% property tax rate (using homestead exemptions). That estimate is somewhat conservative because not everyone is living in the homes, and some are rentals so they don't qualify for those exemptions. These regression results show that. The variable in question is "sghmileop" which just means the property in question is within a half mile of the second generation of train stations and those stations are operational.

What other analysis would be interesting?

I think I want to identify the areas in Houston that have seen the largest appreciation in home value based on key map identifier, but what would help you figure s**t out?