Reassessing Equity Valuation: The Mathematical and Economic Superiority of the Potential Payback Period (PPP)

The Potential Payback Period (PPP) offers a mathematically rigorous and economically interpretable alternative to conventional equity valuation tools such as the Price-to-Earnings (P/E) and PEG ratios. This article demonstrates, through multiple analytic methods, why PPP remains well-defined, stable, and conceptually superior under conditions where traditional models collapse. Using L’Hôpital’s Rule, Taylor expansions, direct limit analysis, and economic reasoning, we show that PPP is uniquely equipped to handle edge cases such as g = r, negative or near-zero earnings, and fast-growing firms with delayed profitability. The analysis culminates in positioning PPP not merely as a replacement for the P/E ratio, but as a unifying valuation metric across equity and fixed-income instruments.