Explain the advantages and disadvantages of the use of different fiscal mechanism used by governments?

Answer 1

By fiscal mechanisms I'm assuming this would involve various market manipulations such as open market sales of government securities, of foreign currencies, of corporate securities, as well printing of currencies and expansionist purchasing.

The advantages have chiefly to do with efficiency, effectiveness and accuracy. Efficiency means it can be done cheaply. Effectiveness means it functions well. Accuracy means that if you are targeting interest rate, how much do you impact overall growth or unemployment as a side benefit/disadvantage.

Disadvantages have to do with side effects (trade imbalances, currency crunches, inflation) market reactions (if you follow Lucas Classicalism), and sustainabily of interventionist methods.