When is it appropriate to model for tax increases?

[Matthew Metros]

Do Property Taxes Increase year over year? I ask because I have seen financial models where they keep property taxes static each year. It does make sense to me as to why taxes would remain static each year, since your tax hikes can occur from government (federal, state, local...) Or if your property receives a high appraisal.

So, my underlying question is when is it appropriate to model for tax increases.