We challenge a set of common assumptions that are frequently used tomodel interdomain routing in the Internet. We draw assumptions from thescientific literature and confront them with routing decisions that areactually taken by ASes, as seen in BGP feeds. We show that the assumptions aretoo simple to model real-world Internet routing policies. We also show thatASes frequently route in ways that are inconsistent with simple economicmodels of AS relationships. Our results should introduce a note of cautioninto future work that makes these assumptions and should prompt attempts tofind more accurate models.