Macroeconomics — Fundamentals

GDP — the three measurement approaches, in detail

•Expenditure approach: GDP = C (consumption) + I (investment) + G (government spending) + NX (net exports, i.e., exports minus imports). This is the most commonly cited formula and the one used in most headline GDP reporting.

•Income approach: sums all income earned in the production process — wages paid to labor, profits earned by firms, rent earned on land/property, and interest earned on capital — since every rupee spent (expenditure approach) ultimately becomes income to someone in the economy.

•Output/value-added approach: sums the value added at each production stage across all sectors (agriculture, industry, services), avoiding double-counting by measuring only the value each stage adds, not the full value of intermediate goods that get counted again at the next stage.

Nominal GDP vs. real GDP

Nominal GDP measures output at current prices, meaning it can rise simply because prices rose, even if actual physical output didn't increase. Real GDP adjusts for price-level changes (inflation), measuring output at constant prices from a chosen base year — this is why real GDP growth, not nominal GDP growth, is the standard measure of genuine economic growth. Confusing the two is a common error: a country reporting high nominal GDP growth during a high-inflation period may have much lower (or even negative) real GDP growth once inflation is accounted for.

Inflation — measurement and causes

Inflation is typically measured using a price index — most commonly the Consumer Price Index (CPI, tracking a representative basket of consumer goods and services) or the Wholesale Price Index (WPI, tracking prices at the wholesale/producer level) — with the inflation rate calculated as the percentage change in the index over a period. Inflation's causes are broadly categorized as demand-pull (aggregate demand growing faster than the economy's productive capacity, pulling prices up) or cost-push (rising input costs, like oil prices, pushing production costs and therefore prices up independent of demand conditions) — this distinction matters because the appropriate policy response differs: demand-pull inflation is more directly addressable through demand-reducing monetary/fiscal policy, while cost-push inflation is harder to address through demand management alone.

Unemployment — types and measurement

Unemployment is measured as the share of the labor force (people working or actively seeking work) who are without work. Economists distinguish several types: frictional unemployment (temporary, from workers between jobs or new entrants searching), structural unemployment (from a mismatch between workers' skills and available jobs, often due to technological or economic structural change), and cyclical unemployment (from a general economic downturn reducing overall labor demand). This distinction matters for policy: cyclical unemployment responds to demand-stimulating fiscal/monetary policy, while structural unemployment requires different interventions (retraining, education) since the problem isn't insufficient demand but a skills/location mismatch.

Getting started

1.Master the expenditure-approach GDP formula (C+I+G+NX) as the anchor point — most macroeconomic policy discussions reference which of these four components a policy is trying to influence.

2.Internalize the nominal-versus-real GDP distinction early — a large share of GDP-related exam questions and real-world economic reporting hinge on this distinction.

3.Learn to classify inflation as demand-pull or cost-push, and unemployment as frictional/structural/cyclical, since these classifications directly determine which policy tool (Advanced) is the appropriate response.