Getting the variables right is just the first step

You may have seen the previous post, announcing a Global Delphi in Public Transport. It is time to situate this article within the overall research project of which it is part.

The connection between organisational form and performance in public transport systems[1] is debated, directly or indirectly, for many years (e.g. Chadwick, 1859). It remains a relevant discussion and continues to spur new research. These analyses indicate that some organisational elements (e.g. market deregulation, use of competitive tendering and contracting, existence of single transport authorities etc.) might be important for achieving different performance objectives (e.g. efficiency, patronage, sustainability etc.). However, a closer look at academic literature in this field reveals that there is still need to further explore aspects not yet properly addressed. Most articles in the field deal with such causal connection in a superficial way, assuming a direct and simple relationship between one or some organisational elements and one or a few isolated performance objectives. Eventually, these studies bring inconsistent and/or inconclusive results.

This is the research opportunity that we (Fabio Hirschhorn, Wijnand Veeneman and Didier van de Velde) are exploring. We want to look at the relationship between organisational form and performance in public transport with new eyes. In particular, by proposing that if/when said causality can be empirically attested, it is complex and needs more in-depth examination. Rather than deriving from simple and direct isolated organisational changes, performance-related outcomes can result from the combination – at the same time or in sequence – of the impacts from different organisational variables (or a configuration of them). Furthermore, to bring more certainty and refinement to any causality claim, it is necessary to assess whether any variable is either sufficient or necessary to bring about certain outcomes, as well as to check whether other variables or combinations of them could also produce same effects. The hypothesis supported here is that there is no silver-bullet to explain public transport performance based on organisational form and that possibly any explanation must go beyond formal structural mechanisms.

Overview of Research Object:

Using a mixed-method research, combining qualitative and quantitative analysis of data, we hope to shed light on existing patterns and clarify some of the mechanisms through which the causal relationship organisation-performance works. The work is built based on three blocks:


Block One: Getting the variables right

The first step to unveil the complexity of the relationship between organisational form and performance consists in properly understanding how both organisation and performance are seen and dealt with in the public transport sector. In particular, given the impossibility to analyse all existing variables at once, it is important to define which variables (both independent and dependent) are more relevant and deserve further scrutiny. To get the variables right, rather than doing a review of academic literature, the choice here is to develop a Global Delphi Survey with experts in public transport. Employing the ranking-type Delphi we will produce two authoritative rankings, comprising most relevant organisational features and performance aims (with respective quantitative indicators) to be analysed. These rankings, built based on views of those who are most knowledgeable about the field, are developed by using multiple questionnaires carefully crafted to elicit opinions from well-known experts acting in varied roles (academia, transport authorities, operating companies, users’ representatives etc.) – thus covering multiple perspectives in worldwide-spread public transport systems.

The ‘Delphi Selection Process’:


Block Two: Assessing the actual behaviour of selected variables

As a follow-up to the Delphi’s findings we will build a comparative case study assessment, using Qualitative Comparative Analysis (QCA). Putting it simply, our aim is to take those variables selected as most relevant by sector experts in the Delphi, and analyse them in concrete cases. This will be done to compare public transport organisation and performance in metropolitan areas within some OECD member-countries, but more sets of cases can be later added to the study. This approach is consistent with the hypothesis that underpins the PhD (mentioned above) – QCA is based on the understanding that social phenomena are better comprehended in terms of configurations of factors, combinations of conditions that come together simultaneously or in sequence, leading to certain outcome(s). Therefore, as a tool and methodological approach it suits nicely the hypothesis we propose. Instead of analyzing relationships between two or three variables (standard variable-oriented approach), it allows the comparison of cases by comparing different configurations of independent variables that may be associated with the presence or absence of an outcome.

Comparative case-study:


Block Three: Making things more complex – adding time and informal structures

A final block of this research project will be based on within-case studies of selected metropolitan areas amongst those initially analysed in the QCA set. The purpose is to properly open the black-box of public transport governance in 3 or 4 cases to be studied in depth. This in-depth analysis of cases will add to the findings obtained in the Delphi and the QCA in at least two important ways. First, it includes the longitudinal dimension and therefore takes into account the historical evolution of public transport systems, shedding light on factors that are critical and peculiar to specific systems. In particular, it adds in relation to the QCA block because QCA in its original formulation does not take into account the order in which events occur and treats combinations of attributes as though they take place simultaneously. Secondly, the within-case analysis will allow for the consideration of informal elements also possibly impacting public transport, i.e. those aspects that are not part of the formal structure of the system and nonetheless are impact its performance. These elements can be informal channels of communication and other forms of informal coordination, politics and power dynamics, leadership character of particular individuals able to drive changes, the skill-set of the entity responsible for public transport planning etc. 

Adding the time dimension and informal structures (outside formally designed system):


[1] The expression Public Transport refers to metropolitan collective modes of land passenger transport services available to the general public with no limitation to state ownership, nor public sector management, planning or provision.


Chadwick, E. (1859). Results of Different Principles of Legislation and Administration in Europe; of Competition for the Field, as Compared with Competition within the Field, of Service. Journal of the Statistical Society of London, 22(3), 381–420.