Human resource accounting (HRA) involves treating expenditures related to human resources as assets rather than expenses. It provides useful information for planning, personnel policies, utilizing human resources effectively, and attracting the best employees. There are cost-based models that value human resources based on historical or replacement costs, and economic models that use opportunity costs or discount future wages to determine present value. Common models include capitalizing acquisition and training costs, using replacement costs, and discounting expected future salaries to calculate present value. HRA can provide valuable information to managers and investors.