Some adjustments to the human capital and the friction cost methods.

The cost of lost output is a major component of the total cost of illness estimates, especially those for the cost of workplace accidents and diseases. The two main methods for estimating this output, namely the human capital and the friction cost method, lead to very different results, particularly for cases of long-term absence, which makes the choice of method a critical dilemma. Two hidden assumptions, one for each method, are identified in this paper: for human capital method, the assumption that had the accident not happened the individual would remain alive, healthy and employed until retirement, and for friction cost method, the assumption that any created vacancy is covered by an unemployed person. Relevant adjustments to compensate for their impact are proposed: (a) to depreciate the estimates of the human capital method for the risks of premature death, disability or unemployment and (b) to multiply the estimates of the friction cost method with the expected number of job shifts that will be caused by a disability. The impact of these adjustments on the final estimates is very important in terms of magnitude and can lead to better results for each method.