A rise in government expenditure injects additional money into the economy. When the government spends more on infrastructure, salaries, transfers, or public services, aggregate demand increases. If the economy is already operating near full capacity, this increased demand cannot be matched by a proportional increase in the supply of goods and services. The result is higher inflation, a sustained rise in the general price level.
This outcome is explained by demand-pull inflation: excess demand relative to available supply bids up prices across the economy.
Higher government spending does not lead to higher unemployment; it typically reduces unemployment by creating jobs and stimulating economic activity. It does not directly cause lower profits for industries, since increased demand often boosts sales and revenue. It also does not lower importation of raw materials; in fact, higher economic activity often increases imports as firms need more inputs to meet rising demand.
The link between increased government expenditure and inflation is a central concept in fiscal policy analysis and is especially relevant when an economy is near or at full employment.