produced items are concerned, Governments and arms manufacturers qenerally do not wish to supply figures. Moreover, for the most sophisticated products such information is usually top secret and not at all available. This underlying difficulty is not unique for the military sector but it must be admitted that it is much more difficult to obtain basic information in this area than in other areas, although some countries are relatively open on weapons costs or prices; (b) The actual prices of material are not always fully known. They depend, inter alia, on research and development which has taken place earlier, sometimes with both civilian and military objectives in mind. The fixed costs incurred during the first years are reduced in per unit terms by subsequent production in large suantities, but taking into account the instability of the market, it is difficult to know the number of equipment units over which the initial costs should be spread. Moreover, certain types of weaponry may be difficult to price separately as being parts of complex arms systems. In such cases, it may not be possible for countries to fiqure out the price of each product component, especially if a single firm has provided the entire system; / . . . A/40/421 English Page 17 (c) Except for the most simple products (guns or hand-grenades, for instance), it is often difficult to compare a weapon produced in one country with a similar weapon produced in another country. The characteristics are different and the qualities of eauipment vary with the defence arrangements, industrial infrastructure, innovative capacity and the technological level of the country concerned. Moreover, military equipment is sometimes developed in small series or belong to the class of unique goods, a veritable nightmare for statisticians. Finally, the incessant renewal of military goods and the continual changes in their 
**Analysis**
The text appears to be discussing the challenges of obtaining information about military production and prices, including the difficulty of comparing weapons produced by different countries. The language used is technical and focused on the production and development of military equipment, suggesting that the text is related to the industry and manufacturing of military products.

**Category**
Industry, Science and technology