Excluding an Expert Witness's Testimony on Lost Profits
Robert Chapman posts about a Mississippi case determining that a trial judge did not abuse his discretion in excluding an expert witness's testimony on lost profits. The Mississippi court's primary concern in Webb v. Braswell was that the both the lost profits themselves, and the expert testimony about them, were too speculative under Mississippi law. Specifically, the lost profits were on unplanted crops, which the court implied are inherently too speculative, and there was no proof that the business had ever been profitable in the past (to the contrary, it was apparently losing money). Because the existence of lost profits was too speculative, the trial judge did not abuse his discretion in excluding as unreliable the expert testimony of an agricultural economist as to the amount of lost profits.
For Tennessee's view on an economist's testimony as to lost profits, look to Waggoner Motors, Inc. v. Waverly Church of Christ. In Waggoner, Middle Section Court of Appeals Judge Koch went over Tennessee law on the degree of proof required for compensatory damages, including those for lost profits. Judge Koch also analyzed the requirements for expert testimony on lost profits, ultimately rejecting an economist's testimony because of flaws in the economist's methodology.
You can also take a look at this response to a motion to exclude an economist's testimony posted over at MedMalBlog.com.