Hmm, I think it's more accurate to say that the debt is the integral of the deficit. It's not like Congress passes laws to set the debt, then we examine how muc

Hmm, I think it's more accurate to say that the debt is the integral of the deficit. It's not like Congress passes laws to set the debt, then we examine how much the debt changed year to year and call that the deficit. Instead they pass a budget that exceeds (typically) tax revenue by a certain amount, and the shortfall (the deficit) is raised by borrowing money, which adds to the existing debt. You could argue that "the debt is the integral of the deficit" is equivalent to "the deficit is the derivative of the debt" but in that case, I could construct a well-defined quantity which is the definite integral of the debt starting from the year, 1800 and the deficit would then be the fourth derivative of that quantity.