The economy should be diverse and have a growing population.  

Lyndon B Johnson's "Guns and Butter" devasted the US economy.

What is the local economy? 

@Brian Garlington Dallas has a booming economy with great job and population growth but because of some of the highest property taxes and insurance rates in the nation, the returns are very low in comparison to Midwest markets like Indianapolis and Kansas City. 13-14% return are not realistic however when you take in to account vacancies and maintenance which a lot of people neglect to include.

The end result is entirely dependant on the economy between now and the date you sell.

A reversal of the economy can easily see equity disappear and along with it the principal pay down "profit".I do not know who you are referring to when you state that "It's commonly accepted ......." but it is not the investors I associate with.

It would also be more beneficial for my family should I become seriously injured, ill or pass away.Over the years I have seen property values rise and fall with the economy.

@Copeland DuhonThere are a lot of posts on this subject, but I'll take a crack at a high level:Macro environment: rule of law, diversity of regional economy, positioning of regional economy, etcSupply and demand equation for properties, both on the sale transaction side, and on the rent side. 

Indianapolis was appealing due to low price to rent ratio, generally cheaper homes, lower property taxes, and a diverse economy.

People trade down when the economy worsens.