Resumen: Millions of people travel every day by car in cities around the world, with daily mobility being one of the main contributors to CO2 emissions. Bicycle-sharing systems are a mobility alternative to cars that may help to reduce CO2 and GHG emissions. We analyze a public bike-sharing service (BIZI, in Zaragoza, Spain, May 2008–August 2019, 24 million uses), from the perspective of both efficiency and demand profiles, to determine whether the use of bicycles in the city can be increased. We study the evolution of the use of the BIZI service, showing that efficiency increased rapidly at first and reached an optimum value after the first two years. Using regression models, we characterize the groups that use this service the most and relate bicycle demand to factors such as weather conditions, number of bike lanes, and service extensions. Our analysis allows us to characterize the demand for BIZI as being subject, primarily, to weather conditions. This factor may reduce or boost the demand for this kind of service, which may help bike-sharing firms to decide on possible locations. Idioma: Inglés DOI: 10.1016/j.eap.2022.09.015 Año: 2022 Publicado en: Economic Analysis and Policy 76 (2022), 745-754 ISSN: 0313-5926 Factor impacto JCR: 6.5 (2022) Categ. JCR: ECONOMICS rank: 31 / 380 = 0.082 (2022) - Q1 - T1 Factor impacto CITESCORE: 6.9 - Economics, Econometrics and Finance (Q1)