(3) Cobweb phenomenon The agriculture commodities often reflects the Cobweb phenomenon, where supply reacts to price with a lag of one time period because supply decisions take time to implement, the beginning of this years planting of crops farmers are influenced by the price prevailing last year Supply B+B2P++p（3）Cobweb phenomenon The agriculture commodities often reflects the Cobweb phenomenon, where supply reacts to price with a lag of one time period because supply decisions take time to implement, the beginning of this year’s planting of crops farmers are influenced by the price prevailing last year Supplyt=B1+B2Pt-1+μt