New day, new ideas: Treasury Secretary Tim Geithner wants to boost our primary line of credit to the International Monetary Fund by $90 billion to give emergency support to the world’s struggling economies. The proposal, which requires congressional approval, offers a hint of the administration’s global economy strategy ahead of the G-20 summit in London on April 2. While Washington would expand its line of credit to the IMF to $100 billion from $10 billion, other countries would also be expected to boost their funds, including China, which so far hasn’t chipped in so much as a penny. If all goes as planned, the IMF will have $500 billion to loan, a ten-fold increase from its old budget. Geithner will push the plan this weekend at a finance ministers’ meeting in London.