Factors determining the size of flows in macroeconomics:

Current Prices:
- Current prices play a significant role in determining the size of flows in macroeconomics. Prices impact the level of consumption, investment, and overall economic activity in an economy. For example, higher prices may lead to a decrease in consumer spending, while lower prices may stimulate the economy by encouraging more spending. Changes in prices can also affect the cost of production, which in turn influences investment decisions by businesses.

Changes in Stock Variables:
- Stock variables, such as the level of savings, investments, and capital stock, can also determine the size of flows in macroeconomics. For instance, an increase in savings can lead to higher levels of investment, which can boost economic growth. Similarly, changes in the capital stock, such as investments in infrastructure or technology, can impact the level of economic activity and flows in the economy.

Government Intervention:
- Government intervention through fiscal policies, such as taxation and government spending, can affect the size of flows in macroeconomics. For example, an increase in government spending can stimulate economic activity, while higher taxes can reduce consumer spending. Government policies can also influence the allocation of resources and impact the overall flow of goods and services in the economy.
In conclusion, while there are various factors that determine the size of flows in macroeconomics, current prices play a crucial role in influencing consumption, investment, and overall economic activity. Additionally, changes in stock variables and government intervention through fiscal policies also play a significant role in shaping the size of flows in the economy.