(Bloomberg) — One of President Barack Obama's top economic advisers said abusive trading practices are costing workers billions of dollars in retirement savings each year and called for stricter rules on Wall Street brokers.

Jason Furman, chairman of Obama's Council of Economic Advisers, drafted a Jan. 13 memo citing research that says some broker practices, such as boosting commissions with excessive trading, cost investors $8 billion to $17 billion a year. The document was circulated to senior aides and indicates the White House may support tighter oversight of brokers who handle retirement accounts.

The memo, obtained by Bloomberg News, makes the case for a Labor Department regulation that would impose a fiduciary duty on brokers handling retirement accounts, requiring them to act in their clients' best interest. Under current rules, brokers are held to a 'suitability' standard, meaning they must reasonably believe their recommendation is right for a customer.