Facing increased competition, over the last decade many stock exchanges changed their trading fees to maker-taker pricing, an incentive scheme that rewards liquidity suppliers and charges liquidity demanders. Using a change in trading fees on the Toronto Stock Exchange, we study whether and why the breakdown of trading fees between liquidity demanders and suppliers matters. Posted quotes adjust after the change in the fee composition, but the transaction costs for liquidity demanders remain unaffected once fees are taken into account. Yet, as posted bid-ask spreads decline, traders, in particular retail, use aggressive orders more frequently, and adverse selection costs decrease. JEL Classification: G12, G14. Keywords: Liquidity rebates, market quality, trading, maker-taker pricing, retail trading * TSX Inc. holds copyright to the data, all rights reserved. It is not to be reproduced or redistributed. TSX Inc. disclaims all representations and warranties with respect to this information, and shall not be liable to any person for any use of this information.The equity trading landscape has changed dramatically over the past two decades, bringing with it a host of new policy concerns. Technological innovation in the 1990s allowed the entry of fully electronic trading platforms, known in the United States as electronic communication networks (ECNs). Subsequent regulatory reforms 1 facilitated the competition among trading platforms, eliminated the privileges of incumbent exchanges, and ultimately forced the incumbents to abandon physical trading floors and become electronic limit order markets.In a limit order market, a trader can either specify the desired price and quantity by posting a limit order or the trader can accept the terms of a previously posted limit order by submitting a market order. To compete for trading volume, during the last decade most equity trading platforms in North America introduced cash incentives for posting attractively priced limit orders. These cash payments are part of an incentive scheme known as maker-taker pricing. Understanding the impact of trading platforms' innovative offerings, such as maker-taker pricing, has become increasingly important in the new competitive environment. In the past, exchanges in North America were non-profit entities with a mandate to serve their members. Facing stiff competition, they converted to shareholder-owned corporations, raising concerns that their profit-motivated "incentive schemes may run counter to the integrity of pricing and investor protection. 2 "Regulatory Role of Exchanges and International Implications of Demutualization" by Roel C. Campos, March 10, 2006, available at http://www.sec.gov/news/speech/spch031006rcc.htm. 1 or aggressive [market] order, is charged a fee." 3 Maker rebates aim to improve liquidity, by rewarding its provision, and to increase trading volume, yet theoretical studies have shown that they need not affect liquidity and that trading volume may, in fact, decline.Angel, Harris, and Spatt (2011) argue that ...