In this the book we present the Meta Regression as a technique that is widely used technique in applied economics, than we prove and test 2 out of 6 international macroeconomics puzzles: Feldstein-Horioka puzzle, and Baxter-Stockman neutrality of exchange rate regime puzzle. Also we investigate the issue of inflation and unemployment trade off and the money and output.Also we write about population and growth theories and we empirically test the theories on a sample of Balkan countries.The authors are :Dushko Josheski and Darko Lazarov and we also thank our co-authors Nikola V. Dimitrov and Cane Koteski.