Charles Lane asked the right question in his April 2 op-ed, “Can the post office be a bank?” He just got the answer wrong.

Mr. Lane asked “what’s the practical alternative?” to payday lending, an industry with a business model that often traps users into vicious cycles of debt. Mr. Lane wrote that lenders are a better alternative than loan sharks. He failed to report that payday lenders charge annual interest rates of 300 percent to 400 percent! They are “legal” loan sharks.

Nearly 100 million Americans are underserved by traditional banks. Many are seniors who cannot travel very far. Postal banking is a practical, public alternative to the great need for financial services. It offers a business model to protect consumers from abusive practices with control over their financial lives.

The arguments in favor are many: location and accessibility of post offices, experience with financial services, a popular and trusted public institution, and proven success around the world. Mr. Lane’s major concern is that postal banking “would short-circuit potentially beneficial innovation by the private sector.”

Given the track record of the existing private-sector options — from banks “too big to fail” to payday lending — the time is now to institute a proven solution: postal banking.

Richard Fiesta, Washington

The writer is executive director of the Alliance for Retired Americans.