taking only the information of this video "https://www.youtube.com/watch?v=AaS3ywvuuTQ" answer the next questions, remember you just need the information of this video, don't take any other sources:

1. Why did so many countries increased their public debt in the last 2 years?
2. What was determined as the main cause for the high inflation in the 1970s?
3, How is the increase in public debt worldwide related to current inflation levels?
4. Why does austerity (reduce spending) does not work in a time of crisis?
5. Olivier Blanchard argued countries could borrow far more than previously believed. Why did he believed that?