Weather derivatives: Definitions Heating degree days (HDD): For each day this is max(o, 65-4)where a is the average of the highest and lowest temperature in°F Cooling Degree Days(CDD): For each day this is max( o, A-65)
An alternative to the NPV Rule for Capital Investments Define stochastic processes for the key underlying variables and use risk- neutral valuation This approach (known as the real options approach) is likely to do a better job at valuing growth options, abandonment options, etc than NPV