National income includes net income from abroad i.e. difference between export value and import value (X-M) and net difference between receipts from abroad and payments made abroad (R-P)
Gross National Product does not take into consideration the cost in terms of (i) Environmental pollution, (ii) Depletion of natural resources caused by production of output
Mere increase in GNP will not reflect improvement in quality of life, when it increases environmental pollution or reduce available resources for future generations