Real interest rates have fallen to historic lows, and some economists are concerned that an era of secular stagnation has begun. This column highlights the role of policy frameworks and financial factors – particularly debt – in linking low real interest rates and sluggish economic growth. Policies that do not lean against booms but ease aggressively and persistently in busts induce a downward bias in interest rates over time and an upward bias in debt levels – something akin to a debt trap. Low real interest rates may thus be self-reinforcing and not always ‘natural’.