| Organizations have communicated about their environmental protection activities with publics via various media channels. As social media have become popular in the past decade, organizations have begun to communicate about environmental issues using these channels. This dissertation aims to understand the current nature of organizations' sustainability messages on social media and to test the effects of the messages on audiences' attitude, belief, and behavioral intention. To achieve the purposes of the study, three series of studies were conducted. Study 1 analyzed the green message content of for-profit and nonprofit organizations on a popular social media platform, Twitter. Study 2 used attribution theory to examine how the substantiation and specificity of green messages influence receivers' attribution and attributional processes. Using a scenario of green messages on Twitter and Facebook, Study 3 investigated the effects of message substantiation and specificity on affective and cognitive responses (attitudes toward message and organization, credibility of both the message and organization, and perceived organizational green image) and the effects of the affective and cognitive responses on green behavioral intentions (intention to engage in the green campaign and intention to purchase the organization's green product) and social media reaction intentions toward the green message (like, share, and comment intention). The results showed that associative and vague messages were more prevalent than substantive and specific messages on Twitter. In particular, for-profits' messages tended to be substantive and specific, while nonprofits' messages were generally associative and vague. For for-profit organizations, messages about environmental facts led to more likes, shares, and comments than other green message orientations. Furthermore, a specific message increased perceived intrinsic motivation and decreased perceived extrinsic motivation of the organizational environmental communication. The perceived intrinsic motivation was positively and the perceived extrinsic motivation was negatively associated with message attitude, organization attitude, message credibility, organization credibility, and green image. The results of this study attest that substantive and specific messages positively drove the affective and cognitive responses which positively predicted green behavioral intentions and social media reaction intentions. |
