に伴って・に伴い

This grammar expresses that one event or situation occurs together with, or as a consequence of, another event or condition. It highlights a correlation or parallel change: when X happens, Y also changes, or changes in response to X. The に伴って form is more neutral and is often used in descriptive or reporting contexts, whereas に伴い is slightly more formal and is common in written language such as news, reports, or policy texts. Both patterns attach to nouns and verbs in dictionary form (for verbs) and imply a cause-and-effect or accompanying relationship. Typical contexts include social/economic changes, policy effects, natural events, or everyday shifts that accompany another change.