关键词: 蔬菜价格, 外部冲击, 面板向量自回归模型（PVAR）

Abstract: On the basis of building panel vector auto-regression model（PVAR），the authors
empirically analyzed the impact of external shock on fluctuation of vegetable price；and found that
except GDP growth rate，which had a significant impact on price fluctuation，other variables contributed
only 1.5%-3.3% to price variation. Meanwhile，considering the impact from variable，when given the
subsidies-LBT a standard differential impact，the vegetable price-LJG would response negatively and
reach a maximum in the third period．When given the vegetable disaster area LCZ a standard deviation，
the vegetable price - LJG would initially turn a negative response then to positive response in the third
period. When given GDP growth a deviation shock，vegetable price-LJG showed a distinct positive
response．When given the LCZSR a deviation shock，vegetable price-LJG showed negative response．
Therefore，the effect of external shock to vegetable price is not ideal，there exists hysteresis qualityin its response to partial external shock. Consequently，building a sound vegetable industry market
mechanism，improving the efficiency of vegetable circulation，and ensuring the balance between
vegetable supply and demand are important measures to inhibit t he violent fluctuation of vegetable price.

Key words: Vegetable price, External shock, PVAR