11.   The report says that the economic value of the oil and gas field could become uncertain if electricity generating companies are forced to use more British coal.

12.   And it may, for instance, be possible to gauge in narrow terms the relative economic value of clear-cut logging vs. recreational use of a forest.

13.   As appealing as this thought is, Sen may sound to some a little defensive about the economic value of freedom.

14.   Because China centralizes aircraft purchases under China Aviation Supplies, it can use aircraft orders to emphasize the economic value of good relations with Beijing.

15.   Because the government centralizes aircraft purchases under its China Aviation Supplies Corp., it can use aircraft orders to underline the economic value of good relations with China.

16.   A historical artifact like a city, it recognizes, has an economic value that goes beyond tourism.

17.   A trade secret must have independent economic value.

18.   Brynjolfsson asserts that the economic value of speed, quality improvements, customer service and new products are often not captured by government statistics.

19.   But defenders of the forest say there is economic value to standing trees, and to the rich wildlife they support.

20.   But economic value increasingly comes from less generic, harder-to-measure, and often intangible goods.