Sharing economy originally grew out of the open-source community, then gradually refers to peer-to-peer based sharing of access to goods and services\citep{wikipedia}. Citi Bike is one of typical businesses benefited from sharing economy. Launched in May 2013, Citi Bike has become an essential part of transportation network through its bike sharing system, and also become the largest in the nation. The bikes can be unlocked from one station and returned to any other station in the system, making the ideal from one-way trip with efficient, affordable and environmentally friendly\citep{nyc}.
Young people are always regarded as the main supporters towards new things. According to \citet*{2012} research, consumers will be encouraged to engage in sharing economy because of rational reasons, such as saving and practicality, and emotional reasons, such as feel altruistic and part of community. Young people are especially driven by emotional motivations because they desire to feel smart and fashionable\citep{schmitt1999}. Therefore, it is reasonable to assume that young people tend to support Citi Bike more than other groups. Similarly, Citi Bike also treat young group as their main target consumers. For example, they held the campaign named “Promoting Bike Share Through Youth Engagement” at April 2018, which clearly indicated the target participators are “Young adults aged 16-24 years old who live, work, or go to school in the Citi Bike service area”. 
Overall, it is interesting to test this assumption that whether young people tend to support more than other groups, which is also useful for Citi Bike in implementing effective promoting campaigns. Fig. 1 shows my null hypothesis and its corresponding math expression with significant level.