**6. Conclusion and further research**

*Agricultural Economics - Current Issues*

increase in a long term.

**5. Discussion**

First year revenues generated through urban rooftop farming were found to barely offset the costs in Hong Kong. In the prototype case, the gross costs and benefits of urban rooftop farming in the first year were HK\$ 730,400 and HK\$ 764,760, respectively. In subsequent years, the annual recurrent commercial benefits exceeded the annual recurrent costs HK\$ 530,400, giving a benefit-cost ratio of 0.32 (234,360/7,304,000), which suggested a likely payback period of 38 months. This factors in the high initial capital cost to establish a rooftop farm which includes building retrofitting costs and the purchase of equipment. Farm managers reported that the business stabilized after the second year and revenues were expected to

However, the current amount of payment is based on a narrow view of farming participation (HK\$ 190 per month/person/half square meter). As suggested by the willingness to pay analysis, once participants took into account the social values derived from their farming activities, they might be willing to pay more (HK\$ 220). If fees were raised to this level, it would significantly alter and increase the gross benefits (to HK\$ 872,760 per year) and shorthorn the payback period (to 26 months). The results suggest that cost-benefit analysis provide a useful basis on

In Hong Kong, formal green initiatives in the urban area have come a long way from the development of public parks in the 1970s to the promotion of green roof designs through sustainable building directives in the 2000s. However urban rooftop farming has not been formally recognized and exists still within gray areas

As evidenced by these findings, the disparity of multifaceted social values aligns with previous literature on social capital theory. Cognitive values are directly related to the individuals in the society such as the effects of health and education improvement, while structure values are indirectly built through expanding network in society which needs more efforts to achieve. For instance, collective assets like the urban economy prosperity and social solidarity not only improved by mobilizing individuals through urban rooftop farming but also need more complex catalysts. Different levels of understanding of social values have been identified within previous landscapes value research [37]. Individual perceived values in the landscape, concentrating on health and general wellbeing, have most readily been identified: collective values relating to spatial planning and resource management have been less mentioned by subjects. This disparity is also rooted in the physical nature of existing urban rooftop farming practices. According to observations made during this research, rooftop farming activity is explicitly individual due to space limitations. A large number of planting plots were arranged side by side within physically constrained roof spaces, inhibiting interaction. Participants work by themselves on individual plots while only "keeping an eye" on surrounding plots farmed by others. This mode of operation might explain the higher perception of direct personal health and education benefits. The lack of additional social space in social enterprise farms and the solitary nature of individual farms may reduce perceptions of collective social value such as engagement of the community or

Previous research has not explored the monetary influence of social benefits, which is required for urban rooftop farming to be incorporated into urban policymaking. For instance, on average the payback period for farms is shorter than for green roofs in Hong Kong (27 months) and for ground-level urban agriculture

which to reconceive the financial viability of the urban rooftop farms.

of urban planning legislation and building control.

improvement of the urban environment.

**110**

A shift in the thinking about the products of urban rooftop farming from food security and urban greening to social benefits and positive support to activate urban rooftop spaces would create significant opportunities for aligning individual motivations and state interests, thereby achieving a more sustainable city. Though current urban rooftop farming is undertaken by individuals and grassroots organizations, with limited policy or technical supports from city authorities, users still perceived considerable social benefits in the form of sustainable living, environmental knowledge and enhanced relationships within social groups. Users' willingness to pay for the experience indicates that urban rooftop farming is a passive social activity which can be enhanced by collaborative activities and by-products of farming which include talking, working side by side, standing and comparing.

The implication of the multifaceted social values of rooftop farming suggests a changing perception of urban agriculture. With the increasing speed of urban densification, urban agriculture, constituted by complex social values and diverse interests from stakeholders, has the capacity to be a public good for cultural exchange and enhancing social coherence. This changing perception suggests the need for greater stakeholder support, recognition in legislation and integration with urban planning and building control processes. As an emerging urban activity, further studies are required. For instance, the higher preference for health and education as social benefits in this research requires more specific study to develop detailed instruments for those single indicators within particular groups. In addition, as this study only addressed the social values of urban rooftop farming in Hong Kong, further studies in different contexts and forms could help to expand the urban agriculture discourse.
