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Andy,
The scale effect in the transport model can be explained. I use a European option to do the illustration. I raise the underlying and strike price by the same amount, use the fuel percentage to adjust the strike. The net result is the intrinsic value decreases as the level goes up. If the fuel percentage is not very high, the option premium actually increases with the level, although the intrinsic value decreases. If the fuel percentage is very high (<8%), then we see a decreasing option price. In the transport deal, fuel change is often below 5%, so you will not see a decreasing spread option price when NYMEX moves up. So I think the transport model still does what it should do. Zimin In the following exmaple, I used r=6%, vol=20%, T=100days, see spreadsheet for details. ---------------------- Forwarded by Zimin Lu/HOU/ECT on 10/20/2000 01:24 PM --------------------------- Zimin Lu 10/20/2000 10:45 AM To: Andrew H Lewis/HOU/ECT@ECT cc: Colleen Sullivan/HOU/ECT@ECT, Stinson Gibner/HOU/ECT@ECT Subject: level effect in transport Andy, The following spread sheet domenstrates the leve effect in transport valuation. I add an "NYMEX add-on" to both delivery and receipt price curve before fuel adjustment, keep everything else the same. The transport value (PV of the spread options) increases when NYMEX add-on increases. I can visit you at your desk if you have further question. Zimin
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