1) RBS measures employee engagement through annual employee surveys, joiner surveys, leaver surveys, and targeted pulse surveys. It calculates an Engagement Index based on responses to questions about recommending RBS, thinking about leaving, and being inspired to work hard. 2) RBS implements various initiatives to improve employee engagement such as learning and development programs, flexible working policies, and recognition awards. 3) High employee engagement at RBS has led to benefits like increased productivity and profitability, lower turnover, and positive correlations between engagement and tenure.