Originally Posted by ermdjdsj
Does anyone have a quick summary or link to various airline tier-dropping policies?
No, but the three airlines I have ever had status with (all non-US based ones) have an only-drop-one-level policy, even if you don't fly - SAA, BMI and Qantas. I.e. on all of them, if you are Gold you will drop no lower than Silver the next year, even if you don't step on a plane.