Front Cover

Many countries have conducted studies to determine the monetary impact of power system outages on their customers. These studies have been conducted for different customer classes and have used a wide range of survey or study techniques. The data is being used to examine reliability levels and criteria and to provide input to planning and operating decisions. One issue often raised is the question of comparable reliability criteria in different systems and different countries. The customer interruption costs (CIC) in different countries can be compared by converting the CIC data using purchasing power parity (PPP). A PPP estimate reflects the purchasing power of the inhabitants of a country and depends on market value. The effect of frequent currency fluctuations due to artificial reasons are eliminated in the PPP estimate. In the PPP approach, the prices of goods and services are internationally arbitraged so that the cost of a standard market basket is the same in all countries when measured in terms of a common currency.