## 5 Conclusions  
Green public procurement is expected to reduce environmental impacts and save resources through public procurement. Beyond the public sectors, the leading role of government in the application of environmental technologies and products enhances green development in broader society. To promote GPP, the influential factors which encourage or hinder its application are important. This research aims to find out what aspects can have effects on the adaptation of green award criteria in the contracts with Probit regression and fixed term analysis, using the contract award notice data in 33 European countries in 2018. The data set includes various business sectors and various procurement procedures. We find that framework agreements, of the medical equipment sector, health and social services sector, and business services sector are negatively related with whether a contract is green, with 1% significance. On the other hand, contract value, GPA coverage, joint procurement, competitive dialogue, negotiation with a call for competition, restricted procedure, transport equipment, and food sector can positively correlate with green contract, or these factors increase the possibility of a contract being green statistically significantly (1%). The contracts applying open procedure possess a lower possibility of green contracts by 5.6%, comparing with contracts with other procurement procedures. After further exploration, we found competitive dialogue, negotiation with a call for competition, and even restricted procedures are positively correlate with green contract, which are more proper for complex form of procurement, like GPP. The contracts with competitive dialogue have a higher probability, of 19%, to apply green award criteria than other procedures. For the contract value and joint procurement, 1% growth in contract value will increase the probability of the contract being green by 0.48%, and joint contracts are more likely to be green, with a higher likelihood of 4.3%. This implies that a larger volume or value can promote the uptake of green contracts because of larger incentives, while reducing the risk of economic operators. The four essential sectors for GPP recognized by EU are construction, transport, food, and electrical products. We conclude that GPP is not implemented widely enough in construction work and services, compared with its share in total public purchasing. We determine that transport equipment contracts have a higher possibility to be green, by 5.8%, but did not obtain significant results for transport service. What is more, the food sector is estimated to possess a higher green likelihood (8.4% higher) than other sectors, while no supportive results are found for the electrical products sector. From our results, transport equipment and food demonstrate a better uptake, while more efforts are needed for construction and electrical products. What is more, comparing with the contracts within framework agreements, those without framework agreements have a higher possibility of being green, by 3.1%. This method hinders green criteria, possibly by leaving out green tenderers outside the framework. Last, consistent with its proposals on the environment, GPA positively relates with a contract applying green award criteria. For future research, the authors recommend investigating green specifications/criteria covered in the whole process of public procurement activities. This research only looks into the green vocabularies included in the contract awarding stage, selecting the final bid winner, which does not take consideration of environmentally related requirements before and after this stage in the procurement process. The green vocabularies identified by authors in determining whether a contract is green or not are restricted to the current 19 sectors with established GPP criteria by the European Commission and confined to limited research time and resources.