How can one use macroeconomics to accurately model the global economy?

Macroeconomics variables can be used to accurately model the global economy, which are as follows:

Inflation: Inflation rate is also a determinant of macroeconomics which can b used to determine global economy. Inflation charts of countries can be compared and studied to have an image of inflation prevailing globally.

Interest rate: if the interest rate of the country is high then it will attract foreign investment because investors only invest in profitable projects. So, interest rate will determine the capability of a country to attract foreign investment and therefore, contribute to the global economy.

Exchange rate: with the rise in the world trade on account of globalisation exchange rate has become the most vital determinant of a country's relative economic health. Stable exchange rate indicates sound economic management and flow of trade between the countries. But of the exchange rate is unstable it will hinder the trade flow and thus global economy will be affected.

Many other factors such as monetary policies, fiscal policies, capital investment, resources also affect the global economy thus, should be taken into consideration to model the complexities of the global economy.