In marketing there is concept called brand loyalty. From the Wikipedia post I just linked:
Brand loyalty is defined as positive feelings towards a brand and dedication to purchase the same product or service repeatedly now and in the future from the same brand, regardless of a competitor’s actions or changes in the environment.
It's not too difficult to see how a concept like this could be applied to transit. The real research question here is whether customers have an implicit loyalty towards riding the bus or the train, and whether they would they continue to use them if other modes become available. I have to say that a 2015 research paper in the Journal of Public Transportation from Shiftan et al. (DOI: 10.5038/2375-0901.18.1.7) really motivated this blog post. The authors survey bus and train riders in Tel Aviv and use a marketing framework to analyze the results of the survey. The paper I linked to actually contains all of the survey questions and the methodology they used to administer the survey.
A Short History of Brand Loyalty in Marketing
Thankfully, since this is just a blog post I'm going to rely mostly on the research paper's literature review instead of doing one of my own. To start off, the value of a product is related to three different values: a utilitarian value (how useful something is), a switching value (it is difficult to switch from one thing to another), and the hedonic value (the experiences and emotions someone associates with a product). The output of a typical model with these three factors is the level of satisfaction (exactly what you think) and the loyalty (a customer's willingness to repurchase a good). I haven't read the book, but according Shiftan et al.'s literature review Levinson splits loyalty into four different categories:
- Cognitive Loyalty - (knowing, forms after a short-term experience)
- Affective Loyalty - (attitude, forms after a longer-term experience)
- Conative Loyalty - intention, when somebody develops an emotional attachment
- Action Loyalty - re-buy, when customers will automatically repurchase a product because of their past experiences
Traditional Utility Theory usually talks about passengers preferring public transit modes with a high level of service (think low travel time, low cost, etc.). However, these marketing concepts differ from traditional Utility Theory ideas and may actually show that fewer passengers may shift to new modes due to loyalty to an old one. Shiltan et al. argue that loyalty models are not used in Transportation Research, and I do not disagree with that assessment from the limited amount that I've seen. Transit researchers might be reluctant to use these techniques because they rely on a "deeper investigation of the subjective and emotional effect on consumer choice."
I'll let you look at the survey yourself in the paper but they conduct the investigation in six different stages:
Theory – developing a full loyalty theory as a basis for the research.
- Measurement scales – identifying measurement scales from marketing to measure
the factors included in the loyalty model and adopting these scales to the mode-
choice problem in transportation.
- Level-of-service factors – identifying some level-of-service factors to be included in
- Survey – creating a database of a representative sample of PT users to measure the
- Measurement – measuring the factors using the factor-analysis technique.
- Validation – validating a full loyalty model in transportation using the structural
equation model (SEM) technique.
To avoid going too far beyond fair use, I am not going to show a photo of the diagram the authors use but their loyalty model matches the one in the literature review pretty well. They use Oliver's four-stage loyalty model. For Level of Service, they use standard factors like reliability, cost, and in-vehicle travel time. They also considered comfort (think air conditioning, bus seats, how crowded it is) and convenience (safety, relaxation, etc.). All of these scales are established from past research papers. They conducted the survey with bus and rail passengers in the Haifa-Tel Aviv corridor which are about 100km apart. They surveyed 286 rail passengers and 219 passengers.
So far I do not have any issues with the methodology. They surveyed a decently large number of people, so as long as the sampling was actually random (they don't specify how they ensured that) their methods seem pretty good so far. They measured marketing factors by doing a Factor Analysis and validated the model using the Simultaneous Equation Model (SEM). I might dive into that in a future blog post but for now I'll leave it to you to learn more about it. In addition, some of the survey questions are a little wordy and include hypotheticals: "Buses will remain my favorite mode choice in the future." After all, who knows what will happen in the future.
Do transit riders exhibit loyalty? In short, yes. However, they could not differentiate between the four stages of Oliver's loyalty model. There was also an emotional value that the researchers could identify. Surprisingly (to me), the researchers were not able to identify utilitarian value or satisfaction factors in either the bus or rail passengers. So what's lacking here? I would have loved to see a traditional analysis on the data using good ol' Utility Theory. A lot of the survey questions are hypothetical which isn't ideal either. Overall though, this study suggests that marketing theories would be really useful in reshaping how we think about transit issues.