Administration implementation of environmental pollution control necessarily requires to accumulate and analyze information which represents the environmental conditions or states in detail. Recently, economical study has received much attention on environmental information because budgets for environmental pollution prevention have been strictly limited.
Benefit of information, defined as “saving of excessive countermeasure cost brought by increased information”, is generally difficult to obtain quantitatively because the information always includes intangibles. The smaller volume of information thus makes the estimated errors larger in curtailment of emission derived from the simulation models. The larger margin in an actual emission control may be therefore essential to attain the ambient air quality standard X0 with some probability P0. This could result in higher countermeasure costs both in administration and in industries.
One of the purposes in this study is to develop an actual cost effectiveness anlysis (CEA) for information on sulfum oxides (SOx) that includes old history in environmental pollution control strategy. Another purpose is to determine optimum information volume to maximize “effectiveness of information” under the area total mass emission control (ATMEC). This paper deals with CEA on SOx-emission under ATMEC in Osaka prefecture. The ATMEC has strictly required the factories to cut down total emission of SOx based on the simulation models so as to attain the air quality standard over prefectural region.
The prefectural region was covered by 30 monitoring station. The environmental information collected and/or accumulated was consistent of air monitoring, meteorological monitoring and emission at various sources. The information on countermeasure costs was collected and/or accumulated by hearing from factories and plant manufactures concerned.
The effectivenes of information was estimated or determined by the use of the information in the process from collection of the information at the planning stage of ATMEC until appearing of its effects in final results of the administrative works. As a result, the number of monitoring stations increased by one was estimated to save 200 million yens per year in the emission control strategy in Osaka prefecture. On the other hand, cost of collecting information is genarally given as increase function of information volume. Accordingly, the budgets expended for collecting information could be presented as a linear function of information volume. This function enabled to determine the optimum information volume so as to find out minimum cost (Information Cost+Emission Control Cost). Since the cost however includes unknown parts which are independent of information volume, the optimum information should be determined from intersection of marginal benefit curve with marginal cost curve. The analysis suggested that the optimum number of monitoring stations is 40 with probability P0=90% in the Prefectural area where 30 stations were distributed.
