The fluctuation of vegetable prices in recent years underscores the need to identify contributing factors and develop effective policies. In order to examine the factors affecting the fluctuation of vegetable prices, this paper uses a structural model constructed by demand, supply, import, and export functions to decompose price variance, and also performs a numerical simulation to generalize the results. We studied the Korean vegetable market, and selected cabbage, radish, dried red pepper, garlic, and onion as research objects. The results indicates that variability of domestic production is the primary factor that influences price fluctuations in the Korean vegetable market. In contrast, our analysis revealed that demand, import, and export had a limited impact on price fluctuations in the Korean vegetable market, except for dried red pepper and onion.

The eco-friendly certification system is designed to ensure safe agricultural products to consumers while minimizing environmental pollution. However, despite its advantages, it is not widely adopted due to a possible decrease of farmers’ income. In order to provide implication for activating the eco-friendly certification system, this paper examines the attributes of green tea which affect consumers’ preferences and estimates consumers’ willingness to pay (WTP) for the eco-friendly certification in China. A choice experiment survey is employed for data collection, and the random utility model is used to estimate the preference for the certification and quality of green tea. The attribute that yields the highest marginal WTP turns out to be the organic certification for which WTP is $115.9/250 g higher than for no certification. Also, the analytical results indicate that the group with high trust is willing to pay up to $214.6/250 g more for green tea with organic certification compared to the one with no certification. The empirical results suggest that it is important to build the consumers’ awareness and trust toward the certification to activate the eco-friendly certification system.