National income statistics — common mistakes

In exam questions, always be clear whether you are discussing nominal or real data. When asked to compare economic growth over time, you must refer to the change in 'real GDP' to show the examiner you understand the distorting effect of inflation.

In evaluation questions, do not simply list limitations — explain why each matters for the country in the question. E.g. "In a low-income economy with large subsistence agriculture, GDP understates true output."

Not necessarily. A higher GDP indicates greater economic output, but it is not a direct measure of welfare. It fails to account for factors such as income inequality, the value of leisure, environmental degradation, and unpaid work. A country could have a high GDP but poor living standards for the majority of its population if income is highly concentrated.

In this scenario, nominal GDP would double because it is calculated using current prices. However, real GDP would remain unchanged. This is because real GDP is adjusted for price changes to reflect the actual volume of output, which, in this case, has not changed. This illustrates why real GDP is the crucial measure for assessing economic growth.

No, this is a common misconception. Whether GNI is higher than GDP depends on the balance of international income flows, not the level of development. Some developed countries, like Switzerland, have large net inflows of property income, making GNI > GDP. Others, like Ireland, host many multinational corporations that repatriate profits, leading to large net outflows and causing GNI to be significantly lower than GDP.