How might Keynesian economic theories justify government intervention during a recession through fiscal policy measures?

Keynesian economic theories suggest that during a recession, the economy can become stuck in a low growth phase where people spend less money. This reduced spending can lead to businesses making less profit, which may cause them to cut jobs or lower wages. To help the economy recover, Keynesians believe that the government should step in and increase spending, known as fiscal policy, to stimulate demand. For example, if the government builds new roads or invests in schools, it creates jobs and encourages people to spend money, helping the economy grow again. By doing so, the government can help pull the economy out of a recession and reduce unemployment.