Final answer:
The study of how losses cumulate over time to predict how recent losses are likely to develop is known as loss development.
Step-by-step explanation:
The study of how losses cumulate over time to predict how recent losses are likely to develop is known as loss development in the field of actuarial science. Actuaries use statistical models and historical data to analyze loss trends and estimate the future development of losses for insurance companies and other risk-bearing entities.