## 2 Methodology and Data
### Data and Variables
_\"If a value variable is missing, this variable looks for it in all other fields from which it could be taken\"_ (refer to reference [14] for more details). Supplies, works, and services are three types of contract subjects in the database. From the coded data description of the dataset, \"a work means the outcome of building or civil engineering works taken as a whole that is sufficient of itself to fulfil an economic or technical function\" [15]. To avoid the dummy variable trap, we set only two dummy variables for two types of subject matters: products and services. These two variables have more contracts and larger total contract values than the others. Directive 2014/24/EU defines a framework agreement as \"an agreement between one or more contracting authorities and one or more economic operators, the purpose of which is to establish the terms governing contracts to be awarded during a given period, in particular with regard to price and, where appropriate, the quantity envisaged\" [16] (p. 114). The World Trade Organization Government Procurement Agreement is a multilateral agreement aiming to create a level playing ground for suppliers from member states in bidding for government procurement. Members of GPA are subject to principles including but not limited to nondiscrimination, transparency, and rules for technical specification, selection, and evaluation of tenderers [17]. \begin{table}
\begin{tabular}{c p{284.5 pt}} \hline \hline
**Aspects** & **Environmental Terms** \\ \hline General words & environment, environmental, sustainable sustainability, green, ecology, ecological, wildlife \\ \hline Reduced emission and toxicity & emission, pollution, waste, CO2, NOX, PM10, PM2.5, toxicity, hazardous, seasonal produce, vegetable fats, vegetable oils, waste prevention, waste sorting, organic, chemical restriction, noise emissions, biodegradable, renewable, waste management, management of waste, double side printing, air quality, air pollution, pollutant, GWP, hazard labeling, SVOC, titanium dioxide, TiO, low-noise, carbon footprint, CF, soil management, wastewater, COD, Sulfur emissions, GHG, greenhouse gas, organic gaseous carbon, OGC, particulate matter, PM \\ \hline Resource efficiency & energy, water efficiency, water consumption, gas consumption, fuel consumption, resource efficiency, dimming, AECI, LED, water saving \\ \hline Labels and criteria & ISO 14001, EMS, EMAS, FSC, PEFC \\ \hline Life Cycle cost analysis & recycle, recycling, recycled, recyclable, lifetime, whole life cost, lifecycle cost, ecolabel, eco-label, warranty, warranties, longevity, repairable, repair, repairability, repairability, repairable, endurance, replacement, end-of-life, durability, dismantling, dismantle, disassembling, reuse, re-use, reused, reusable, recosubed, recovered fibers, maintenance, rehabilitation, LCA, waste recovery, LCC, life cycle cost, lifespan, take back, take-back \\ \hline Source: authors’ elaboration. The dataset is in 28 official languages of EU and the vocabularies are translated into each language with Google Translator. GWP, the Global Warming Potential. SVOC, Semi-Volatile Organic Compounds. AECI, Annual Energy Consumption Indicator. EMAS, Eco-management and audit scheme. In ISO 14001, International Organization of Standardization (ISO) specifies the requirements for environmental management system helping one organization to improve its environmental performance. FSC, Forest Stewardship Council, [[http://www.fsc.org/en/](http://www.fsc.org/en/)]([http://www.fsc.org/en/](http://www.fsc.org/en/)). PEFC, Program for the Endorsement of Forest Certification, [[http://www.pefc.org/internet/html](http://www.pefc.org/internet/html)]([http://www.pefc.org/internet/html](http://www.pefc.org/internet/html)). \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Environmental vocabularies for green contract identification. Contracting authorities compare the offers and base its final decision on award criteria.