<prompt> Human: My home loan is 4 while my retirement accounts fluctuate with at least being double that.Is there a threshold that can be crossed for either figure where working on the mortgage would be more beneficial?  <response>: There are financial and risk-related reasons one might pay down the mortgage, including:- Eliminate MIP or PMI- Reduce principal balance below maximum allowable for interest deduction- Increase free cash flowOn the risk-management side- Applies money to a generally non-attachable asset- If your investment portfolio is otherwise aggressive, reducing principal balance is a risk-mitigation solution 