We derive the ï¬rst closed-form optimal reï¬nancing rule: Reï¬nance when the current mortgage interest rate falls below the original rate by at least \(\frac{1}{ψ}\)[φ + W (− exp (−φ))]. In this formula W(.) is the Lambert W-function, ψ = \(\frac{2 (Ï +...

We derive the first closed-form optimal refinancing rule for mortgages: Refinance when the current mortgage interest rate falls below the original mortgage interest rate by at least (1/ψ)[φ W(-exp(-φ))], where W(.) is the principal branch of the Lambert W-function, ψ=((√(2(ρ λ)))/σ),...

We derive the first closed-form optimal mortgage refinancing rule. The expression is derived by using the Lambert-W function to solve a tractable class of mortgage refinancing problems. We calibrate our solution and show that our quantitative results closely match those reported by researchers...

The sophistication of financial decisions varies with age: middle-aged adults borrow at lower interest rates and pay fewer fees compared to both younger and older adults. We document this pattern in ten financial markets. The measured effects cannot be explained by observed risk characteristics....

In cross-sectional data sets from ten credit markets, we find that middle-aged adults borrow at lower interest rates and pay fewer fees relative to younger and older adults. Fee and interest payments are minimized around age 53. The measured effects are not explained by observed risk...