| 摘要 |
<p>PROBLEM TO BE SOLVED: To develop stable investment securities for investing in fresh water by computing a virtual value of a substance on the basis of the value of a freely traded product of the substance.SOLUTION: A first index value of water is computed on the basis of the price of a first traded product and on the basis of at least one of the amount of water included in the first traded product and the amount of water utilized to manufacture the first traded product, and a second index value of water is computed on the basis of the price of a second traded product and on the basis of at least one of the amount of water included in the second traded product and the amount of water utilized to manufacture the second traded product.</p> |
