This study contributes to the ongoing discussions about endogeneity of money supply by empirically investigating the G-20 economies including South Asian countries. We used panel data to test the endogeneity of money supply of Post-Keynesian school of thought. The econometric techniques provide exactly quantified results; but, these results are mostly sensitive due to misspecification of the background of theory which has been applied in econometric techniques. The econometrically sensitive results describe the coefficients’ changes which misguide towards policy making process. To check the endogeneity of money supply we proposed an econometric technique-the Generalized Method of Moment (GMM) and C-Statistic. The (C-statistics) direct test of endogeneity of money supply that depend on econometric specification of exogeneity which has not been used in previous literature for panel data evidence. The study provides that the monetary aggregates and money multipliers are endogenous and also endogeneity of money supply exists there in G-20 economies including the Asian countries. There is a two-way relationship between fiscal deficit and bank credits because the results of fiscal deficits are supporting the structuralist and liquidity preference views. The findings also certified and supported the post-Keynesian school of thought that the money is endogenous. That is why the endogeneity of money supply proportionally increasing in G-20 economies and South Asian countries. Supervisor:- Dr Abdul Jalil