Findings from the IP-AHP revealed that Melaka City and Seberang Perai performed better than Kuala Lumpur in sustainable urban development. Both cities are less dense compared to Kuala Lumpur, which is the densest in the nation with 7,299 persons per square km (DOSM 2020). Kuala Lumpur garnered the lowest performance scores for the environmental, economic, and social dimensions between the cities. Items under the environmental “ambience” factor, i.e., pollutions and traffic congestion, were among the worst rated ones by the residents of the city; all of which fell below the average point. In fact, for all cities, the overall environmental scores lied within the low-performance quadrants in the IPA grid, Q1 and Q3. Environmental issues have been some of the biggest challenges faced by cities nowadays (Al-Thani et al. 2018; Koch & Ahmad 2018; Lee & Xue 2020), and the Malaysian cities are no exception. With the expected ongoing urbanization in the country, the government should put more effort and investment into curbing pollutions and congestions in the cities, especially in the densely populated cities where the problems are more severe. For examples, they could enforce tighter laws to monitor and control pollutions, and implement smart technology to reduce traffic congestions.
Although the environmental “conservation” factor was found to be a low priority in this study, it is nonetheless important to conserve the natural environments of cities. Environmental impacts such as deforestation could increase carbon emissions in the city (Arshad et al. 2017). Urban green spaces, for instance, are lacking in Kuala Lumpur and Seberang Perai due to the scarcity of land (Maryanti et al. 2017; Samat et al. 2014), which could be even more so in the future as rapid developments continue. The ratio of green spaces to population in Kuala Lumpur is only 12 m2 per person, which is below the standards set by World Health Organization and Malaysia’s National Urbanization Policy (FDTC 2016). Therefore, the conservation of existing urban green spaces along with innovative incorporation of green spaces into built environments are necessary for the cities’ environmental sustainability.
Kuala Lumpur also fell short in terms of the economic dimension. In what could be the most economically-developed city of the country, the residents of Kuala Lumpur thought that the city was not economically sustainable, at least not for them. Items under the dimension such as cost of living and housing affordability were rated below the average point. The economic performances of Melaka City and Seberang Perai were not so well off either, with each scoring just above average. The citizens’ slow income growth rate that does not match the inflation rate and the increase in property prices till unaffordable levels are among the major factors that contribute to high cost of living in the country (Surendran 2019). Therefore, the government have to provide adequate economic support for the lower-income residents in the cities, such as affordable home ownership schemes, subsidized goods and services, and lower barriers for economic activities. The recent declaration of federal territories in the country as temporary free trade areas is a good example of economic support for the locals (Choong 2020). Other than that, public transportation systems have to be improved to allow people to live in the suburbs, which are more affordable, and be able travel to the city centres to work with convenience. Such effort is important to help develop the suburbs as well (Shao et al. 2019).
With regard to the social dimension, Kuala Lumpur performed the worst in the “wellbeing” factor but the best in the “convenience” factor compared to the other two cities. Regardless, the social performances of all three cities fell within the high-performance quadrants in the IPA grid, Q2 and Q4, with the “wellbeing” factor being the most important of all. These imply that the cities have to keep up the good work in promoting their residents’ wellbeing, such as ensuring safety and security in the city and providing quality health care and educational facilities. Although the means of “convenience” belonged to Q4, which signified possible overkill, the factor should also be taken seriously as good mobility and accessibility to places in a city is a crucial element of urban sustainability (Afacan 2015; UN 2015). Overall, the more favourable finding for the social dimension compared to the other dimensions in this study reflects the upmost focus of the Malaysian government in the urban sector, which is “people-oriented approach and community wellbeing,” as reported in UN-Habitat (2017 p. iv).
As for the cultural dimension, which was the least important factor in this study, Melaka City performed better than the other two cities. Melaka City is in fact a culturally rich city that is a UNESCO World Heritage site, as described earlier. While this factor might not be that important to the residents, culture is still a necessary element of sustainable urban development (Senlier et al. 2009; UN 2015). The cultural heritage of a city or place should be conserved for the continuation of the community’s long-standing identity, pride, and image (Lee & Xue 2020). A city’s vibrant culture could be a factor for tourist attraction as well, driving economic growth and cultural heritage development, as in the case of Melaka City (Teo et al. 2014). Therefore, the local authorities have to create awareness on the importance of local culture and heritage among the current generations, so that they can be preserved well for the use of the future generations.
5.1. Contributions and implications
Theoretically, this paper contributes to the literature by introducing a new method to integrate the IPA with modified AHP, called the IP-AHP, which measures pairwise comparisons in AHP using importance scores from the IPA. As explained above, this method does not require the use of the 1–9 scale but instead, applies measurements of the Likert scales used in IPA, making the questionnaire easier to implement on the general respondents, who can answer without being trained. Moreover, with the administration of factor analysis to statistically group the subcriteria, the use of a larger sample size that is more representative of the population, and the reduced scale in the questionnaire, the validity and consistency of the findings could be enhanced, thus minimizing the need to repeat the survey process to reach a consistent outcome. The formula derived in this study also complies with the measurement of consistency ratio in AHP. The application of the IP-AHP method in this research to assess urban sustainability for the purpose of welfare maximization further contributes to sustainable development and urban literature. This research has shown that, other than using the AHP to make decisions by way of selecting the best alternative, the method can be used to compare the relative performance of cities to facilitate decision making for optimized sustainable developments between the cities. Findings from the IP-AHP have demonstrated the ability of the urban residents to provide useful information on the importance level of the sustainable urban development indicators as well as the performance of cities based on the indicators. Beyond that, the indicators compiled in this paper can be adopted and applied in future urban development research.
On the practical side, this paper has established a method for the local authorities to measure and monitor the sustainability of cities, which can facilitate inclusive and efficient implementations of sustainable urban development initiatives. It is recommended that the residents are surveyed every now and then by the authorities to gauge their perspectives and needs over time as the cities progress. Results from the IP-AHP method could help the government to decide the proportion of resources to be allocated to the examined cities based on their relative performance. The IPA’s findings could also enhance the decision making by providing further insights into the cities’ performances in terms of the indicators. Since the survey is easy to be implemented on the general public, the method is suitable not only in academia, but also in organizational practices.
Specifically, the findings of this study apply to the three examined cities in Malaysia. The analysis shows that Melaka City and Seberang Perai performed better overall compared to Kuala Lumpur, which was taught to be more polluted, congested, and costly to live in among the residents. Nevertheless, the former two cities’ sustainability performance were not that well off either, as the cities’ overall weighted scores and dimension scores were not far apart from each other. Also, even though the IPA ratings were categorized into quadrants of high and low, importance and performance in the grid, the importance ratings were generally within the higher range of above 4.0, whereas the ratings of the cities’ performances were all below 4.0. It can be concluded that much more work has to be done by the authorities that govern the three cities in order to fulfill the needs and expectations of the residents. Further to that, developments in the cities have to be managed strategically in ways that ensure balanced growth in the sustainable development dimensions.
5.2. Limitations and future research recommendations
The measurement items used for the survey in this study were adopted from the previous literature and conceptually arranged according to the dimensions. Future research may conduct a preliminary study, such as using the Delphi method, to identify more sustainable urban development indicators relevant to the topic being studied. This research introduces a new, integrated approach to measure the sustainability of cities from the residents’ perspectives. Future research could use the same method on the urban experts to gain their perspectives which may add value to the outcomes. The sample of this study include a total of close to 600 residents from three cities. Future research may interrogate a greater number of respondents from each city to obtain more accurate findings regarding the individual cities. The study locations of this research are three cities in a single country. Future research could assess cities in different countries simultaneously to compare the sustainable development of cities of different nations and provide more substantial recommendations for improvement. Future research in other disciplines could also apply the IP-AHP method to study other entities’ relative performance.