1. Introduction
The report of the 19th National Congress of the Communist Party of China repeatedly mentioned "green travel" actions, implementing the strategy of green development, and adhering to sustainable development [
1]. In December 2017, the “Opinions on Comprehensively Promoting the Development of Green Transport” was issued by the Ministry of Transport, which was put forward to comprehensively carry out "green travel" actions, deeply implement priority strategies for public transport (PT), and realize sustainable development in transport industry [
2]. Public transport is an integral part of public services, which is a type of public welfare related to people’s welfare and livelihood [
3]. In China, government administrators regard improving the service quality of PT as an important responsibility. In recent years, reforms to public transport service systems have been launched to vigorously develop and support PT. The purpose of these reforms is to increase the number of people who take PT and improve the service quality of PT by changing the currently split model of PT (mainly including supervision mechanism and ownership structure) [
4,
5]. Nevertheless, in the first half of 2017, the ratio of public transport to private car trips in large- and medium-sized cities in China was generally lower than 40%, far below the ideal level of 60% [
6]. The lower travel proportion and lower satisfaction of public transport services was not good enough to meet the people’s travel needs [
7].
In the past 40 years of reform and opening-up, PT in China has achieved a complete cycle, experiencing a development process from a “government-led” mode to a “market-led” mode, and back again [
8] (see
Figure 1). This is in line with the reduced focus on market approaches in the world. Now, many problems have arisen in PT reforms, such as the serious profit loss, poor service quality, and so on. In order to solve these problems, many private capital and operation enterprises have withdrawn from the PT market and returned to the “government-led” mode [
8,
9]. From experience at home and abroad, the government’s arbitrary behavior is facing a dilemma: the “government-led” mode will inevitably lead to a decline in the efficiency of PT. Once deregulated, PT will face inadequate supervision and public dissatisfaction [
10,
11]. In many cities of China, PT reforms have not been successful, and the satisfaction and efficiency have not reached expected goals. The main reason for this phenomenon is that PT supervision mechanisms in China are imperfect or not even in place. Thus, establishing a sound supervision mechanism is an important way to improve the satisfaction and efficiency of PT.
Most scholars have mainly researched supervision mechanisms by studying the contractual form. As PT is a quasi-public good, which simultaneously produces the satisfaction and the efficiency. In the public transport service system, most of the existing literature in this field has focused on the effects of the contractual form on the efficiency of PT from the operator’s perspective. Results in the existing literature have shown that the correlation between efficiency and contractual forms is significant, that is, different contractual forms may incite different efficiencies [
3,
4,
5,
12,
13,
14,
15]. So far, the literature [
9] and [
10] has only addressed the effects of the degree of supervision on the PT satisfaction from the public’s perspective. In particular, research results in the literature [
9] have shown that different degrees of supervision may produce different levels of passenger satisfaction in China. However, urban development in China varies greatly. On the basis of the permanent resident population in urban areas, the sized of urban scale is divided into seven categories: small I sized city, small II sized city, medium-sized city, large-I-sized city, large-II-sized city, mega sized city and super sized city. Thus, it would be beneficial to explore whether the contractual forms have different effects on the PT satisfaction at different urban scales. In small cities of China, multiple modes of passenger transport system coexist, but the service system of PT is usually regarded as imperfect. While in mega cities and super cities of China, the development of PT is electronic and three-dimensional, with rail transit as the main part, and conventional ground public transport and taxi as supplemental parts. Therefore, in reference to the literature [
9] and [
10], taking conventional ground public transport systems in medium-sized cities and large sized cities (including large-I-sized cities and large-II-sized cities) as the research focus, we explored the different effects of contractual forms on PT satisfaction.
To explore the different effects of contractual forms on the satisfaction at different urban scales, data of the contractual forms and PT satisfaction were collected, which covered four large-I-sized cities, four large-II-sized cities and four medium-sized cities, for a total of 12 cities in China. In addition, data on the socioeconomic status, travel characteristics, and city characteristics of the respondents in these 12 cities were also collected. The data set used is one of the contributions of this paper. In the field of PT satisfaction, most studies usually have built and measured the satisfaction on the basic of customer satisfaction index (CSI) and structural equation model (SEM) [
3,
16,
17,
18]. Thus, in this paper, a model of the passenger satisfaction index (PSI) was constructed on the basis of the modified European Customer Satisfaction Index (ECSI), and it was measured by a partial least squares-structural equation model (PLS-SEM). Then, the association between PT satisfaction and contractual form was proposed, and estimated by a two-stage truncated regression model. This is the methodology contributed by this paper.
The remainder of this paper is structured as follow: The measurement of PT satisfaction is introduced in
Section 2.
Section 3 proposes the association between contractual practices and PT satisfaction. The data source and variable selection are presented in
Section 4.
Section 5 elaborates an empirical analysis, which explores the different effects of contractual forms on passenger satisfaction in different cities of China.
Section 6 summarizes the significant findings and an outlook for future research.
Section 2,
Section 3 and
Section 5 are all the cores content of this paper.
3. Association between Contractual Forms and Passenger Satisfaction
Our objective of this paper was to explore the difference effects of contractual forms on PT satisfaction in China’s large- and medium-sized cities. That is, we want to assess the difference relationships between them. However, the true level of the satisfaction with PT is unknown. The true level of the satisfaction,
Si is generated by:
where,
denote the contractual form received by the
ith passenger,
,
is the whole samples.
) denotes the other factors impacting the satisfaction with PT. These are the control variables. In examining public transport satisfaction literature, we found the factors that impacted PT satisfaction were divided into the city’s characteristics [
30,
31,
32], the firm’s characteristics [
33,
34], the travel characteristics [
17,
35,
36], and the socioeconomic characteristics of the passenger [
36,
37]. Based on our objectives and data availability, we chose city characteristics (i.e., city size,
GDP, road area, private car, etc.), travel characteristics (i.e., travel time, usage frequency, etc.), and the passenger’s socioeconomic characteristics (i.e., age, gender, educational level, occupation, etc.) as the control variables in this paper.
and
are the unknown parameters.
In this paper, PSI was used to assess the level of PT satisfaction. The values of PSI were continuous, with a range of 0 and 1, and some values were concentrated at 1. In this situation, the dependent variable was limited. If we used directly the ordinary least squares method (OLS) to estimate the model, this lead to serious deviations and inconsistencies with the estimated parameters [
38]. On the basis of Monte Carlo simulation, the literature [
39] proposed that some of the values are concentrated at 1, where the sample size is a set property of limited samples, which is a small part of the sample. In this situation, the model used a Tobit regression model for estimations, which led to inconsistencies in the estimated parameters. At any rate, the value of PSI measured by empirical analysis is a measured value, not a true value. Thus, there may be a serial correlation between each satisfaction value, and there may be a serial correlation between the variables
,
) and the random disturbance variable
, Bootstrap methods can overcome this problem. Therefore, in referencing the research literature [
39], a two-stage truncation regression bootstrap model was used to estimate the association between contractual form and passenger satisfaction, as shown in formula (2).
where
denotes the value of PSI of the
ith passenger, which is measured by PLS-SEM method according to European Customer Satisfaction Index (ECSI).
denotes the constant parameter.
is assumed to obey normal distribution
, and denotes a stochastic term error [
39].
5. Empirical Analyses
Referring to the factors that impacted PT satisfaction, we construct the model as follows:
where,
denotes the PSI of the
ith passenger, which is measured by PLS-SEM method according to European Customer Satisfaction Index (ECSI).
denotes contractual forms received by the
ith passenger, which includes
,
and
.
is the socioeconomic characteristics group of the
ith passenger, which includes age, gender, income, education, and occupation.
includes the usage frequency of PT and travel time.
represents the city-specific characteristics group, which includes GDP, road area and private car.
denote the unknown parameters of contractual forms, the socioeconomic, travel characteristics, and city characteristics, respectively.
Based on the two-stage truncation regression bootstrap model, we establish the association between PT satisfaction and contractual form, then discuss the different relationships between them in China’s large- and medium-sized cities.
Table 10,
Table 11 and
Table 12 present the results of the association model. The results in
Table 10,
Table 11 and
Table 12 denote the effects of contractual forms on PT satisfaction in large-I-sized cities, large-II-sized cities and medium-sized cities, respectively. The positive and negative signs denote the positive and negative effects of the variables on PT satisfaction, respectively. When three control variables,
,
and
, are added to the two-stage truncation regression bootstrap model in turn, the significant relationship between PT satisfaction and contractual forms is enhanced.
Model (1) of
Table 10 and
Table 11 shows the significant relationship between PT satisfaction and contractual forms in large-I-sized cities and large-II-sized cities, respectively. As can be seen from
Table 10 and
Table 11, in comparing the public transport enterprises supervised by net cost contracts, the coefficients
and
were all positive and statistically significant at the 0.05 probability level. This implied that both management and gross cost contracts had a significant positive effect on PT satisfaction in large-I-sized cities and large-II-sized cities. The coefficient
was larger than that
. This showed that in large-I-sized cities and large-II-sized cities, the operators supervised by management contracts produced the highest PT satisfaction, followed by those supervised by gross cost contracts. Those supervised by net cost contracts incited the lowest satisfaction.
Table 7 presents that the management and net cost contracts had the highest degree and lowest degree of government supervision, respectively. Comparing the satisfaction of the operators with the three contractual forms, we can see that the higher the degree of government supervision, the higher the satisfaction of PT. The reason for this result is that: in large-I-sized cities and large-II-sized cities, not only the public transport infrastructure is ideal, but the government’s supervision is also relatively high, and the subsidy mechanisms are relatively thorough, and in place. Although local departments bears both the revenue and production risks of the operators supervised by management contracts, the government still guarantees sufficient financial subsides for these public transport enterprises. However, at the same time, higher service quality requirements for these public transport enterprises are put forward, which provides a basis for higher passenger satisfaction. The results showed that in large-I-sized cities and large-II-sized cities, if improving PT satisfaction is the goal, then choosing management contracts to regulate PT may be the best.
Model (1) of
Table 12 presents the relationship between PT satisfaction and contractual forms in medium-sized cities. As can be seen from
Table 13, in comparing the enterprises supervised by net cost contracts, the coefficients
was negative and statistically significant at the 0.01 probability level, and the coefficient
was positive and statistically significant at the 0.05 probability level. This implied that in medium-sized cities, compared to management and net cost contracts, operators supervised by gross cost contracts produced the highest satisfaction with PT. An explanation for this result is that: the revenue and production risks of the operators supervised by management contracts are shouldered by the government. Compared with the operators supervised by gross and net cost contracts, the operators supervised by management contracts rely heavily on financial subsidies from the government. However, in medium-sized cities of China, the subsidy mechanisms for PT are imperfect, and financial subsidies are not in place. The deficiency and insufficiency of financial subsidies lead to serious operation losses of public transport enterprises regulated by management contracts. In order to compensate for the operating pressure, the service quality of PT is reduced. The results showed that in medium-sized cities, if improving the satisfaction of PT is the goal, choosing gross cost contracts to supervise PT may be the best, while choosing management contracts may be the worst.
Model (2), Model (3) and Model (4) of
Table 10,
Table 11 and
Table 12 present the effects of the
,
, and
on the satisfaction in large-I-sized cities, large-II-sized cities and medium-sized cities, respectively. Because our objective in this paper was to explore different effects of contractual forms on PT satisfaction in China’s large- and medium-sized cities, we only discussed the impact of these group variables on the satisfaction in medium-sized cities, while we did not analyzed the results in large-I-sized cities and large-II-sized cities. The results of
Table 12 show that: for
, the variables including age, occupation and education level were statistically significant in affecting the satisfaction of PT, while gender and income were not statistically significant at the 0.10 probability level, which is in line with previous studies [
9,
37]. For
, the sign of the travel time was negative, and its coefficient
was statistically significant at the 0.05 probability level, which is consistent with the results obtained in the literature [
17,
36]. The sign of the usage frequency of PT was positive, and its coefficient
was statistically significant at the 0.01 probability level, which implied that the travel time and the usage frequency had statistically significant negative and positive effects on PT satisfaction, respectively. For
, there is a significant negative relationship between PT satisfaction and the private car use, which is in line with the previous studies [
9,
30]. The coefficient
was negative, and statistically significant at the 0.05 probability level. In addition, the absolute value of
was very large. That is, road area had a large, statistically significant, and negative impact on PT satisfaction, which is in line with the previous studies [
9,
30,
32]. The possible reason for this phenomenon is that when the road area is relatively large, the resources for road are very sufficient, which leads to more people choosing private cars to travel and results in a lower sharing rate of public transport and higher requirements for public transport services.
Table 13 presents the results of difference effects of contractual forms on PT satisfaction in large- and medium-sized cities of China. As we can see from
Table 13, in large sized cities (including large-I-sized cities and large-II-sized cities), the PT operators regulated by management contracts saw the highest levels of PT satisfaction, and those regulated by net cost contracts have the lowest satisfaction levels. However, in medium-sized cities, the PT operators regulated by management contracts saw the lowest satisfaction, and those regulated by gross cost contracts have the highest satisfaction levels. In contrast, results in the literature [
9,
10] show that PT satisfaction is highest when operators are regulated by management contracts, and PT satisfaction is lowest when operators are regulated by net cost contracts. However, the literature studies [
9,
10] did not take into account the impact of urban scale. Because of the great differences in urban scale in China, this paper explored the different effects of contractual forms on PT satisfaction at different urban scales. The results found that the different effects of contractual forms on PT satisfaction were significant. This indicated that, under the background of current PT in China, a contractual form is not suitable for all urban scales. Different and appropriate contractual forms and supervision mechanisms should be chosen to regulate public transport services according to different urban scales.
6. Conclusions
Our goal of this paper explored the different effects of contractual forms on PT satisfaction in China’s large- and medium-sized cities from the public’s perspective. First, a PSI measurement model was constructed on the basic of ECSI and PSL-SEM. According to the total 3826 samples in the satisfaction survey, the values of PSI in four large-I-sized cities, four large-II-sized cities and four medium-sized cities, (a total of 12) were measured. Then, the association between PT satisfaction and contractual form was proposed based on a two-stage truncation regression bootstrap model. Finally, this paper applied an empirical analysis. The major findings can be summarized as follows:
The average value of PSI with PT in 12 large- and medium-sized cities is 68.65%, PT satisfaction in large-I-sized cities is the highest, with an average value of 70.02%, followed by large-II-sized cities, with an average value of 68.96%, and that in medium-sized cities is the lowest, with an average value of 66.98%. The passenger satisfaction is not high. The service quality of PT need to be improved to better meet the public’s travel needs.
Different contractual forms incite different PT satisfaction levels, which is in line with previous studies [
9,
10]. However, in large sized cities (including large-I-sized cities and large-II-sized cities) and medium-sized cities, the different effects of contractual forms on PT satisfaction is significant, which is not in line with the results obtained in the literature [
9,
10]. In addition, the impacts of the passenger’s socioeconomic status as well as travel characteristics and city characteristics on PT satisfaction were also discussed. Most of the results were consistent with the results obtained in the literature [
9,
17,
30,
32,
36].
These research findings have the following implications in regard to policy-making: Under the background of the current PT in China, establishing sound supervision and strengthening the government’s supervision for PT are two important ways to improve the service quality of PT. It is best to avoid leaving public transport companies to bear both production risk and revenue risk in medium cities. To improve PT satisfaction, in large sized cities (including large-I-sized cities and large-II-sized cities), choosing the management contracts to regulate PT may be the best. However, in medium-sized cities, choosing gross cost contracts to supervise PT may be the best, while choosing management contracts may be the worst. Thus, according to different urban scales, different and appropriate contractual form and supervision mechanisms should be chosen to regulate public transport services.
The findings in this paper will contribute to exploring the effect mechanism of contractual forms on PT satisfaction and providing theoretical basis for choosing contractual forms according to urban scale and improvement strategies in PT. In further, the comprehensive performance containing the efficiency and satisfaction needs to be further discussed. In addition, the different effects of supervision mechanism on comprehensive performance in different cities are another possible area of future research.