## 1 Introduction  
Green public procurement (and green public purchasing) is recognized as \"an important tool to achieve environmental policy goals relating to climate change, resource use and sustainable consumption and production\" [1]. One of the reasons for this is that \"the public procurement market is considered as the largest business sector in the world\" [2]. By using their purchasing power, governments and public authorities can make important contributions to sustainability goals [1]. Another reason is that a wide variety of items, including vehicle fleets, construction materials, chemicals, electronics and office materials, are publicly purchased. Therefore, public procurement has the potential to contribute to the sustainable consumption and production of various types of products and services. However, many researchers have recognized that the potential of public purchasing/procurement was not fully exploited in the 2000s and early 2010s. Therefore, many previous studies have examined the barriers to exploiting the potential of green public purchasing/procurement. For example, researchers point to financial constraints [3; 4; 5; 6; 7; 8; 9], the small size of public organizations [10; 11; 12; 13], and the lack of awareness [10; 11; 5] as barriers. In terms of other main barriers, many researchers have identifiedorganizational issues such as the lack of senior management support [8; 9; 14; 15; 16] and the lack of clear strategic goals [8; 9; 17]. Some public authorities could actually implement green purchasing/procurement if environmental criteria and/or standards were taken into account during the procurement/purchasing process. Actually, some previous studies uncovered that environmental criteria were taken into account in Swedish road maintenance contracts [18], in the tendering process of Finnish and Swedish furniture regarding the chemical content [19], and in the Norwegian public procurement of Information and Communication Technology (ICT) equipment [20]. Other studies have found that environmental criteria were not taken into account in tender assessments of services by most Swedish municipalities [21], in the procurement of most Swedish construction contracts [22], and in the tendering processes of furniture in Spain [23]. As shown above and by [PERSON] et al. [24], these studies focused on only one category of products and services to determine whether to implement green purchasing/procurement. An exception is [PERSON] et al. [25], but they targeted Canadian large-scale procurements in only three sectors (construction, information technology (IT), and large service categories). However, governments purchase and procure products and services in various item categories. This study will identify the progress that has been made in green purchasing across a wide range of item categories, not only specific categories. If information on green purchasing rates by item category or on the ratio of green products/services to total products/services purchased by category is available, then it will enable us to identify categories where green purchasing has not effectively been conducted and needs to be addressed. From such information, we can also infer the common characteristics of the item categories for which green products/services are either easily or not easily purchased. Understanding these characteristics allows us to develop more effective measures that are tailored to the characteristics of the category that needs to be addressed. A questionnaire survey conducted by the Ministry of the Environment, Japan (MOEJ) enables us to provide such information. In the survey, local governments were asked about the extent to which they were making green purchases for 21 categories, including stationery, office supplies, computers, air conditioners (hereinafter AC units), cars and public works. In addition, the survey covered all prefectures and municipalities in Japan, with a very high response rate of approximately 96%.