econ demand and supply

The elasticity of supply will increase from market period, the short run and to the long run. For example, there is increase in demand on fishes as virus inflection on chicken which shift the demand to substitute of chicken: fishes. In market period, the supply can not increase as there is sudden increase in demand on fishes and prices push up immediately to high level and elasticity of supply is very low (a very steep supply curve). However, the suppliers try to employ more labour and work longer time ( variable factors and variable costs rose, given a certain fixed cost in short run) to increase the supply, the supply curve becomes less-step (a slight increase in elasticity of supply) and price fell slightly. In long run, the suppliers can use more fishing boats, fishing machines, nets and labour (all become variable factors) to increase the supply, the supply curve becomes much lesser-step ( higher elasticity of supply) than in short run, the price will drop accordingly, but still higher than the price without sudden increase in demand due to virus inflection on chicken.

2008-04-22 10:35:33 補充：
Hence, as time increases, the elasticity of supply would also increase.