The price-to-research ratio (PRR) measures the connection between a company's market capitalization and its research and development (R&D) spending. It can be used to compare different companies' R&D spending. It is calculated by dividing a company's market capitalization by what it spent on R&D over the previous 12 months. A PRR between five and ten is a preferred number, as it suggests a company is redirecting current profits into research and development, which should positively impact long-term future returns.