# Sustainable Public Procurement in Central European Countries. Can It Also Bring Savings?
## 2 Materials and Methods
\begin{array}{l}Saving=\beta_{0}+\beta_{1}Type\ of\ contact_{i}+\beta_{2} Frame\ agreement_{i}+\beta_{3}EU\ funds_{i}+\\ \beta_{4}Type\ of\ procurement_{i}+\beta_{5}Consortium_{i}+\beta_{6}Number\ of\ offers_{i}+\\ \beta_{7}Number\ of\ offers\ by\ SME_{i}+\beta_{8}Sustainable\ public\ procurement_{i}+\varepsilon_{i}\end{array}  \tag{2}\]  
The dependent variable in the model is savings. This is a continuous variable and can reach values from (100,75). The type of contact is a nominal variable and has three values: services, utilities, and works. The framework agreement is a dichotomous variable which indicates whether public procurement was done by framework agreement. EU funds is a binary variable and indicates whether \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Country/Procurement Type** & **Czech Republic** & **Hungary** & **Poland** & **Slovak Republic** \\ \hline Non-SPP MEAT & 3.3\% & 4.1\% & 92.5\% & 0.1\% \\ SPP MEAT & 7.6\% & 10.2\% & 81.5\% & 0.6\% \\ \hline \hline \end{tabular} Source: Authors.  
\end{table} 
Table 1: Proportion of Sustainable Public Procurement (SPP) Most Economically Advantageous Tenders (MEATs) and Non-SPP MEATs by Country. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Country/Sustainability Aspect** & **Czech Republic** & **Hungary** & **Poland** & **Slovak Republic** \\ \hline Environmental aspects & 24.3\% & 64.4\% & 11.9\% & 35.7\% \\ Innovations and Economic & 51.4\% & 2.1\% & 8.5\% & 28.6\% \\ sustainability & 11.6\% & 15.9\% & 6.1\% & 28.6\% \\ Mixed aspects & 12.7\% & 17.6\% & 73.5\% & 7.1\% \\ \hline \hline \end{tabular} Source: Authors.  
\end{table} 
Table 2: Distribution of Individual SPP MEAT Groups by Country. the contract is related to a project or program financed by EU funds [32] (p. 18). The type of procurement is a nominal variable which provides information about the procedure of public procurement. There are two possible cases considered--open procedure or other non-open procedures, such as competitive dialogue, innovative partnership, negotiated with a call for competition, negotiated without a call for competition, and a restricted procedure. The consortium variable indicates if the contract has been awarded to a group of economic operators [32] (p. 21). The number of offers is a continuous variable which gives information about the number of offers that have been proposed by competitors. The number of offers by SMEs indicate the number of offers that have been proposed by small and medium enterprises. Sustainable public procurement is a binary variable that indicates whether the MEAT used in public procurement focused on any aspects of sustainable public procurement or not. The test of the model effects is shown in Table 3. According to the p values, the null hypothesis of zero effect significance of the explanatory variables can be rejected. Thus, all considered explanatory variables have some discernible effect on the dependent variable. A test of the significance of the model was also run, where the hypotheses are as follows:  
**Hypothesis H0:**_The suggested model is not significantly suitable for the data._  
**Hypothesis H1:**_The suggested model is significantly suitable for the data._  
The likelihood-ratio chi-square is 1038.508 on 14 degrees of freedom, with \(p\) value \(<\)0.001. Thus, the null hypothesis can be rejected that involves the idea that explained variance in a set of data is significantly smaller than the unexplained variance.