Arbitrage and liquidity are interrelated. Liquidity facilitates arbitrageurs’ trading on deviations from the law of one price. However, whether arbitrage opportunity leads to an increase or decrease in liquidity depends on the cause of the deviation. A demand shock leads to greater liquidity,...

We survey the literature analysing the price formation and trading process, and the consequences of market organization for price discovery and welfare. We develop a united perspective on theoretical, empirical and experimental approaches. We discuss the evidence on transaction costs and the...