This document compares and contrasts the input-output (I/O) model and resource-based view (RBV) model for achieving above-average returns. The I/O model focuses on analyzing external opportunities and developing internal skills to capitalize on them. It involves finding an attractive industry and implementing a strategy aligned with that industry. The RBV model instead focuses on a firm's unique resources and capabilities and finding environments where they can be exploited. It involves identifying core competencies, competitive advantages, and selecting strategies that leverage a firm's strengths against external opportunities. Both models aim to earn superior returns but differ in their strategic focus - either external environments or internal resources and capabilities.