What is the test for damages for loss of capital asset in a motor vehicle accident case?

In Klein v. Dowhy, Mr. Justice Stewart awarded damages for loss of future earning capacity to a plaintiff who was 22 years of age at the time of his injury. In finding entitlement to an award, Stewart J. made no reference to any necessity to prove a future loss of income. At para 15, he stated the issue (in terms of the “capital asset” approach) in this way: . . . . has the plaintiff been rendered less capable overall from earning income; has he been made less marketable or attractive; has he lost the ability to take advantage of all job opportunities that might come his way; has he been rendered less valuable to himself in the job market?