Presentation Information
[C19-03]Can peer pressure or social pressure on collaborative activity reduce rice-field abandonment?
Akiko Ohtsuki1, Hiroyuki Yokomizo2, *Mayuko Nakamaru1 (1. Institute of Science Tokyo (Japan), 2. National Institute for Environmental Studies (Japan))
Keywords:
evolutionary game theory,agent-based simulation,adaptive dynamics,rice-field abandonment,public goods
The rice-field abandonment is one of major problems not only in Japan but also in other East Asian countries. This is caused by aging of agricultural workers, the lack of successor, the institutional constraints regarding land, and other factors. However, besides these problems, we focus on the farmer's activities in rice cultivation. The farmers make two efforts: one for cultivating rice-fields and the other for maintaining public goods such as irrigation system and farm roads. Without maintaining these public goods, farmers cannot cultivate their lands efficiently. If there are many free-riders who decide not to join the maintenance but want to share in the benefit from the activities, the rice-field landscape cannot be sustainable anymore.
Our previous study proposed the model in which a farmer's utility is increased by the rice production by the farmer, the amount of water supply which results from the competition among other farmers, the total investment from farmers to maintain the public goods; the utility is decreased by the number of farmers who have abandoned their own land, the cost of cultivation and the cost of maintaining public goods. We showed that, as a consequence of evolutionary dynamics, farmers do not make an effort for maintaining the public goods, and then do not make an effort for cultivating the land in the well-mixing population where players interact with other chosen randomly from the population. This can be analyzed using adaptive dynamics. In the lattice population where the farm lands are influenced by their neighbors' activities and efforts, we showed that farmers make both efforts by the agent-based simulations.
There are social and peer pressures in maintaining and managing public goods among farmers. These pressures may change the evolutionary dynamics of the farmer's efforts. Therefore, in this talk, we extend our previous study and introduce social or peer pressures to the model. Here, social pressure means that farmers put more pressure on other farmers who make less effort; peer pressure means that the farmers put pressure on other farmers to make their efforts close to their average effort. In the well-mixing population, the analysis of adaptive dynamics shows that social pressure can reduce the rice-field abandonment, but peer pressure cannot. In the spatial structured population, social pressure reduces the rice-field abandonment. Peer pressure, on the other hand, does not influence the evolutionary outcomes, but takes longer time to abandon the rice-field than without the pressure.
These results indicate that social pressure leads to different outcomes from peer pressure. If we can know which pressure is more prevalent in a specific area, we may predict what happens in the area.
Our previous study proposed the model in which a farmer's utility is increased by the rice production by the farmer, the amount of water supply which results from the competition among other farmers, the total investment from farmers to maintain the public goods; the utility is decreased by the number of farmers who have abandoned their own land, the cost of cultivation and the cost of maintaining public goods. We showed that, as a consequence of evolutionary dynamics, farmers do not make an effort for maintaining the public goods, and then do not make an effort for cultivating the land in the well-mixing population where players interact with other chosen randomly from the population. This can be analyzed using adaptive dynamics. In the lattice population where the farm lands are influenced by their neighbors' activities and efforts, we showed that farmers make both efforts by the agent-based simulations.
There are social and peer pressures in maintaining and managing public goods among farmers. These pressures may change the evolutionary dynamics of the farmer's efforts. Therefore, in this talk, we extend our previous study and introduce social or peer pressures to the model. Here, social pressure means that farmers put more pressure on other farmers who make less effort; peer pressure means that the farmers put pressure on other farmers to make their efforts close to their average effort. In the well-mixing population, the analysis of adaptive dynamics shows that social pressure can reduce the rice-field abandonment, but peer pressure cannot. In the spatial structured population, social pressure reduces the rice-field abandonment. Peer pressure, on the other hand, does not influence the evolutionary outcomes, but takes longer time to abandon the rice-field than without the pressure.
These results indicate that social pressure leads to different outcomes from peer pressure. If we can know which pressure is more prevalent in a specific area, we may predict what happens in the area.