Don't know if is considered by the algorithm, but the region will be considered by many users, because it's not that easy to find models with good English skills from Eastern Europe and Southern America.
It is time-consuming to find models from these regions with whom you can have a fluid and in-depth conversation (or simply have your wishes communicated without misunderstandings). In addition, there are cases where you cannot talk to the model at all, but a translator is active in the background.
Therefore, users with lots of money tend to look for models from North America, which means that they receive more and larger tips and are listed higher, while users with a limited budget are more likely to accept the limitations and extra effort needed for SA/EE models.
In general, competition is much stronger for SA/EE models, as these two regions account for the majority of all models. The few North American models stand out directly.