Market concentration

**Market Concentration Factors and Metrics:**
– Factors affecting market concentration: barriers to entry, industry size and age, product differentiation, advertising levels, firm-specific factors.
– Metrics: SSNIP test, 1/N calculation, dispersion among firms’ market shares, various criteria for comparison like stochastic dominance and Gini coefficient.

**Market Concentration Indices:**
– Herfindahl-Hirschman Index (HHI): calculation, interpretation, relationship with competitiveness, regulatory usage.
– Concentration ratio: calculation, evaluation over time, levels of concentration, regulatory implications, historical usage.

**Market Concentration and Firm Behavior:**
– Motivation for firms: relationship between market concentration and profitability, likelihood of collusion, efficiency gained by large firms.
– Collusion: game theoretic models, empirical evidence, implications on consumer welfare.
– Efficiency: inverse relationship with market concentration, impact on costs and profits.

**Market Concentration Impacts:**
– Industry effects: reduced competition, increased market power, implications on costs, quality, options, and innovation.
– Innovation: conflicting views on impact of market concentration, empirical evidence complexity, regulatory efforts to prevent monopolies.
– Market Concentration Effects: negative impact on consumers, reduced competition, potential anticompetitive behavior.

**Research and Economic Implications:**
– Research on market concentration: relationship with margins, mergers, R&D valuation, innovation, measurement methods.
– Economic implications: structure, conduct, performance of firms, barriers to new competition, insights from industrial concentration surveys, importance of industrial organization theory.