The FT makes a hullabaloo out of Greece using special drawing rights (SDR) to pay the IMF earlier this week, referring to the step as "unusual." Zero Hedge predictably grabs the baton and runs as far as it can go with the story. It's a good opportunity to revisit the SDR, a topic I last wrote about back in 2013. The FT claims that the payment of SDRs to the IMF is "the equivalent of taking out a low-interest loan from the fund to pay off another." Here the FT has committed cardinal error #1 when it comes to understanding how SDRs work—SDRs are not lent out by the IMF. I like to think of the SDR mechanism as comprised of 188 lines of credit issued to each of the IMF's 188 members. These lines of credit are denominated in SDR and apportioned according to each countries' relative economic size. Any line of credit needs a creditor. In the case of SDRs, who fills this role? Why, the 188 members of the IMF do. The SDR system is a mutual credit system, or...