“…Although the TPB reflects robust explanatory power in behavioral decisions, its integrity is yet questioned [28]. Based on the review of relevant literature, the exploration of additional constructs that may enhance the predictive power of the TPB has revealed that vast studies did deploy the TPB to investigate the factors of purchase intention for environmental-friendly products and services, such as customers' intentions to visit green hotel [17][18][19]22], to engage and willingness to pay premium prices for ecotourism [21], to purchase organic personal care products [20], to be willing to purchase organic foods [23][24][25], to be willing to pay for green electricity [26], and to select eco-friendly restaurants [27].…”