Competing against whom? Competitor identification and opportunity belief revision

Entrepreneurship theories acknowledge that competitive conditions matter for opportunity beliefs, yet how entrepreneurs identify competitors and how this identification shapes venture concept development have received little theoretical or empirical attention. We develop a process account of how entrepreneurs identify competitors and revise opportunity beliefs and venture concepts in response. Unlike market demand or technological feasibility, competitors are strategic agents who can adapt in response to entry, and as the venture concept evolves, so does the set of competitors it faces. We theorize an adaptive cycle in which encountering a competitor prompts threat assessment, which raises perceived competitive pressure and lowers confidence in venture success while motivating venture concept adaptation that can partly restore perceived viability. A controlled experiment isolates the cycle's components and shows that identical competitive information produces widely divergent threat assessments. A behavioral simulation in which participants develop their own ventures and search for competitors shows that entrepreneurs starting from similar concepts identify largely non-overlapping competitor sets. Some reposition their ventures spontaneously in response to what they find, and adaptation attenuates the link between threat and perceived competitive pressure.