Theoretical framework
3.4. oVerView of the four emPirical StudieS
The overall aim of this research is to gain insight in the implementation of SPP and explain how factors and actors influence the implementation and uptake of SPP. In line with the aim of the research, the main research question is: To what extent and how do organisational factors and actors influence the implementation of sustainable public procurement in the Dutch national government?
As stated earlier, a sequential mixed-method design was selected for this research.
This design allows us to combine the necessary exploration (due to gaps in the litera-ture and a lack of generalizability of research) with the explanation that was required
Methodology 49
to answer, not only the research question, but also to fill gaps in the literature and help advance the field.
The role of different factors and actors were examined in four empirical studies.
The first two are qualitative exploring the role of three specific factors and change agents on the implementation of SPP and the degree of sustainable procurement in seven different cases of SPP. The insights generated were incorporated in the two final quantitative studies where all procurers working in national government were sent a questionnaire. This approach tested hypothesised relationships among variables to allow us to generalise the findings further and allow us to deal with the limitations of existing research as discussed in section 3.2.1. The next sections discuss the method-ology of each empirical study in-depth.
3.4.1 Chapter 4: exploring the role of organisational factors
The first empirical study has a qualitative research design to explore and explain the role of three organisational factors in sustainable procurement projects. The main research question of this study is: How do organisational factors influence the degree of sustainable procurement in public procurement projects in the Dutch national government? A combined case study approach was used to reconstruct the process towards sustainable procurement and to explain the difference between the degrees of sustainable procurement between the cases. A case study was deemed the best ap-proach, as this allowed us to research both “how” and “why” the degree of sustainable procurement was influenced by organisational factors. We were able to trace a pro-cess that leads to a certain degree of sustainable procurement by combining a causal process tracing approach and a co-variational approach thus enhancing the internal validity of the claim that the organisational factors matter (Blatter & Haverland, 2012;
Gerring, 2007). Using a causal process tracing approach required that we selected our cases based on the dependent variable (degree of sustainable procurement). Selecting two cases within the same organisation allowed us to control for other organisational factors (e.g., organisational culture), while still varying the dependent variable. In addition, projects were comparable in size and duration, a dedicated project team procured them, and they were at the same stage of the procurement process. In total, ten semi-structured interviews were conducted with key actors in the procurement projects. The interviews were recorded and transcribed verbatim and coded accord-ing to the study’s central concepts usaccord-ing Atlas.ti software.
3.4.2 Chapter 5: exploring the role of change agents in sustainable procurement projects
The study objective discussed in chapter 5 was to explore the role of change agents in sustainable procurement projects and their influence on the degree of sustainable procurement projects. Recent sustainability studies highlight the importance of change agents as potential catalysts of sustainability initiatives (Dunphy et al., 2007;
Van der Heijden et al., 2012). However, the sustainable procurement literature has not studied the role of change agents in depth. Our study has tried to close this gap in the literature by answering the following research question: What role do change agents play in sustainable procurement projects in the Dutch national government? The study used a co-variational design and semi-structured interviews were the main source of data. This design and method allowed us to explore whether and how change agents were involved in sustainable procurement projects. Seven relevant cases of sustainable procurement were selected via a snowball procedure within two public organisations: the Dutch Ministry of Defence and the Dutch Agency of Public Works and Waterways.
A case is defined as a procurement project procured in 2012-2013 and carried out by a dedicated project team consisting of procurement professionals working in a procurement department of a ministry or agency. A case was considered relevant if it fell under one (or more) of the 52 product categories of the Dutch SPP policy, and if the degree of sustainable procurement could be determined. The cases were selected based on an expected variance in their degree of sustainable procurement.
Organisational and project characteristics were kept similar regarding, for example, the type and size of the organisation and procurement department, as well as the size (> 1 million Euros) and duration (> one year) of the project. In total, 35 interviews were held (on average five per case). The interviews lasted, on average, between 1 and 1.5 hours and were recorded and transcribed verbatim. All the transcripts were systematically and manually analysed on a case-by-case basis to facilitate the analysis and to allow for a systematic comparison of variables in and across the cases. A log containing the origins of all the quotations was kept. The analysis was based on a co-variational approach (Blatter & Haverland, 2012) in which the roles and activities of the change agents and their influence on the degree of sustainable procurement were compared across the seven cases.
3.4.3 Chapter 6: sustainable procurement behaviour as a mediator
The objective of the third empirical study discussed in chapter 6 was to propose and to examine a conceptual framework about sustainable procurement behaviour. The model incorporated insights from the first study into the conceptual model.
Methodology 51
The main research question of this study is Does the individual sustainable procure-ment behaviour of public procurers influence the impleprocure-mentation of sustainable public procurement in public procurement projects and what influences their behaviour? A quantitative survey was deemed the best research method as it allowed us to test the proposed conceptual model. Public procurers working in the Dutch national government filled out the web-based survey concerning the study’s main concepts.
The overall number who responded was 288 persons; a response rate of 31.3% out of the total population sampled of 919 persons. The conceptual model hypothesised that sustainable procurement behaviour mediates the relationship between affec-tive commitment to change, knowledge, and the degree of sustainable procurement behaviour. As such, a software program and data analysis method were needed to test both the significance of the mediation and the fit of the conceptual model to the data.
A structural equation model (SEM) that posits causal relations among the variables with AMOS Graphics version 20 was tested. The overall fit of the models was used using a combination of absolute and relative fit indices (Kline, 2011): relative chi square (CMIN/DF); a goodness of fit index (GFI); a comparative fit index (CFI); a root mean square error of approximation (RMSEA); and, the P of Close Fit (PClose). As the conceptual model includes mediation effects, a bootstrapping method was also employed via AMOS (Hayes, 2009) where 5,000 samples (with replacement) were cre-ated for the available observed sample. The significance of the indirect relations was calculated via these samples. The descriptive statistics and basic inferential statistics were calculated with IBM SPSS Statistics version 21.
3.4.4 Chapter 7: determining the antecedents of sustainable procurement behaviour
The objective of the fourth empirical study discussed in chapter 7 was to propose and to test empirically a conceptual framework about commitment to change and sustain-able procurement behaviour. The conceptual framework suggests that the degree of sustainable procurement behaviour is influenced by commitment to change that, in turn, is influenced by different aspects of the organisational change. Insights from the previous case study discussed in chapter 4, as well as the quantitative study discussed in chapter 6, are incorporated in this conceptual model and hypotheses.
The main research question of this study is: Is the sustainable procurement behav-iour of Dutch public procurers influenced by commitment to change and what are the antecedents of their commitment to change? In this chapter a survey was deemed the most fitting research method as it allows us to test whether there was a causal relation between commitment to change, sustainable procurement behaviour and the hypothesised antecedents. This study was based on the same sample as employed in
study 3 in which public procurers working in the Dutch national government were asked to fill out a web-based survey concerning the study’s main concepts. The overall response was again 288 persons and a response rate of 31.3%. Regression analyses were conducted with IBM SPSS Statistics software (version 21) to test the hypotheses laid down in the conceptual model. In addition, a bootstrap analysis was conducted to test the significance of the hypothesised indirect effects.
3.5. Summary
The mixed-method research design allowed us to combine exploration with general-ization to answer different research questions and to triangulate the findings and see if they are mutually corroborated (Creswell & Clark, 2011). It also let us to deal with existing limitations in SPP research, such as the lack of explanatory and confirmatory studies and limited generalizability.
Four empirical studies were carried out to examine the two research objectives and answer the research questions. The next table shows the different designs, methods, case selection, and data analysis techniques of the four empirical studies.
table 3.1: Outline of the empirical studies
chapter Design method case / population Data analysis techniques 4 Qualitative: case studies
1) Highway (RWS) Systematic analysis (manual)
6 Quantitative: survey Survey Dutch national government SEM (AMOS) 7 Quantitative: survey Survey Dutch national government Regression analysis &
Bootstrap (SPSS)