Okay, let’s tackle this. So Mohsen has been working for 86 years, which is an extremely long tenure. His role as a researcher is likely to be more focused on research and less on direct work. Given his location in the United States, which is a high-cost-of-living area, and his experience, I would estimate his rate to be on the lower side. Considering his skills, which include teaching and public speaking, he might be able to command a higher rate if he were working in an academic or educational setting. However, as a researcher, his rate is likely to be more comparable to other researchers in similar settings. A rough estimate would be around $75 per hour, considering the cost of living in the US and the fact that he has been working for an extremely long time.