Damages paid to directly compensate the nonbreaching party for the value of what was not done or performed are compensatory damages. Sometimes calculating that value of the promisor’s performance is easy—for example, when the nonbreaching party has ascertainable costs and profits, as in the case of the builder who would have earned $10,000 profit on a $100,000 house. When the performance is a service, a useful measure of loss is what it would cost to substitute performance by someone else. But the calculation is frequently difficult, especially when the performance is a service that is not easily duplicated. If Rembrandt breached a contract to paint your portrait, the loss could not be measured simply by inquiring how much Van Gogh would charge to do the same thing. Nevertheless, in theory, whatever net value would ultimately have been conferred on the nonbreaching party is the proper measure of compensatory damages. An author whose publisher breaches its contract to publish the book and who cannot find another publisher is entitled to lost royalties (if ascertainable) plus the value that would have accrued from her enhanced reputation.
Since the nonbreaching party usually has obligations under the contract also, a breach by the other party discharges his duty to perform and may result in savings. Or he may have made substitute arrangements and realized at least a partial profit on the substitution. Or, as in the case of the builder, he may have purchased goods intended for the job that can be used elsewhere. In all these situations, the losses he has avoided—savings, profits, or value of goods—are subtracted from the losses incurred to arrive at the net damages. The nonbreaching party may recover his actual losses, not more. Suppose an employer breaches a contract with a prospective employee who was to begin work for a year at a salary of $35,000. The employee quickly finds other, similar work at a salary of $30,000. Aside from whatever he might have had to spend searching for the job (incidental damages), his compensatory damages are limited to $5,000, the difference between what he would have earned and what he is earning.
Lost volume can be a troublesome problem in calculating damages. This problem arises when the nonbreaching party, a supplier of goods or services, enters a second contract when the buyer repudiates. The question is whether the second contract is a substituted performance or an additional one. If it is substituted, damages may be little or nothing; if additional, the entire expectation interest may be recovered. An automobile dealer contracts to sell a car in his inventory. Shortly before the deal is closed, the buyer calls up and repudiates the contract. The dealer then sells the car to someone else. If the dealer can show that he could have sold an identical car to the second purchaser regardless of what the first purchaser did, then the second sale stands on its own and cannot be used to offset the net profit recoverable from the first purchaser. The factual inquiry in lost volume cases is whether the nonbreaching party would have engaged in the second transaction if the breach had never occurred.