![Market Size and Threshold | The Geography of Transport Systems](https://i0.wp.com/transportgeography.org/wp-content/uploads/market_size_threshold.png?resize=900%2C525&ssl=1)
There is a direct relationship between market size and threshold, which impacts the geography of retail. Each urban center needs a threshold population that varies according to its size to support its activities. Large cities have an important threshold, so there may be few on a specific territory, while many small villages exist.