When a trading program is first launched, the total number of permits must be allocated among the sources of are worth considering. Two options for the initial distribution are worth considering. One is to allocate the permits to existing emission sources based on historical emissions. In this case, the ultimate distribution of the permits would be determined by the market as license holders buy and sell their permits. The other option is to hold an auction, in effect leaving the distribution to the market right from the start of the program.