Below are summaries for three essays that share a common theme: each studies a market characteristic that affects price and consumer welfare. The first essay uses experimental methods to test collusive predictions derived in the price-matching literature. Laboratory data demonstrate that allowing firms to institute price-matching guarantees significantly increases market price and firms\u27 profits. The results apply to markets with both symmetric unit costs and markets with small unit cost differences across firms. The results are robust to the order in which subjects experience each treatment, and evidence that higher profits are the rationale for widespread adoption of price-matching guarantees is also provided. The second essay document...