When a nation's imports exceed its exports, its net export becomes negative. This means that the country is spending more on foreign goods and services than it is earning from its own exports. Essentially, a negative net export indicates that a country is importing more than it is exporting, leading to a deficit in its balance of trade. This deficit can have a negative impact on the country's economy, as it may result in a loss of jobs, reduced economic growth, and increased national debt.