 Expansion may be caused by factors external to the economy, such as weather conditions or technical change, or by factors internal to the economy, such as fiscal policies, monetary policies, the availability of credit, interest rates, regulatory policies or other impacts on producer incentives.Global conditions may influence the levels of economic activity in various countries.Economic contraction and expansion relate to the overall output of all goods and services, while the terms inflation and deflation refer to increasing and decreasing prices of commodities, goods and services in relation to the value of money.