What are the indicators of a good/healthy rental market

[Dean D.]

Hi all, 

I am looking at finding my first "buy to let" property. What indicators can be used to guide in deciding where to purchase a rental property?

I can do a search on a property site for a given area, but what metrics can be used to determine if it's a good place to buy? 

Is it number of available rental units? 

Is it price of rental units? 

General quality of available units? 

Etc.

Any advice is much appreciated. 

Dean

[Jake Johnson]

What i've been looking at personally: 

-Rising population, rising job market/median income, crime rate, vacancy rate, distance to the city center.

The biggest thing i've been looking for is stable job markets and vacancy rates. Vacancy rate is what i've been measuring the supply and demand with. I get that rate from property managers i've been calling