| Urban decentralization has emerged as a worldwide phenomenon in recent decades. Co-location hypothesis suggests that employment tends to follow population to decentralize into sub-centers so as to improve jobs-housing balance and avoid long-distance commuting. Together with a well-designed transit system, it is possible that carbon emissions from commuting could be controlled during urban decentralization. However, whether this low-carbon commuting scenario can be realized is under heavy debate. On the one hand, the co-location process has not been fully understood because of methodological limitations and difficulty in data collection. On the other hand, whether co-location hypothesis and related theories are applicable in China is unclear particularly due to a different political and socio-economic context. This research attempts to address these issues, using Beijing as an example. Building on existing scholarly work, this thesis analyzes Beijing's decentralization pattern and commuting efficiency, which reveals changes of urban structure as well as commuting pattern at the city level. For a more comprehensive understanding, this thesis investigates the relationships between urban decentralization and commuting emissions by delving into relocation behaviors of commuters. Characteristics at the community level are included to examine their influences. To take this further, using the panel data of residents' commuting behaviors, this thesis employs multilevel models to explore and distinguish the effects of urban decentralization on commuting emissions at the individual level and those at the temporal level. The results of this research suggest that, while employment decentralization tends to reduce commuting distances of suburban residents, it raises commuting distances of urban residents. Meanwhile, residents' commuting mode choice is strongly affected by household car ownership in both urban and suburban areas, and car-oriented development suppresses the effects of other factors, including employment decentralization. Overall, because of the slow pace of employment decentralization and the increasing car commuting, commuting emissions maintain a rising trend for Chinese cities. The policy implications of this research are significant. The decentralized concentration and transit-oriented development should be promoted in a simultaneous manner to achieve emission reductions. So far opportunities remain for Chinese cities to control the total commuting emissions, but only if Chinese cities so choose. |
