Assume there is no discretionary increase in government spending. Explain how an improving economy will affect the budget balance and, in turn, investment and the trade balance.

An improving economy generally implies increased economic growth, reduced unemployment, higher consumer spending, and increased business investment. This overall positive economic environment may lead to higher government revenues (through taxes) and reduced government expenditures on unemployment benefits or other social programs. This impact on the government's budget balance will be analyzed in more detail in the next step.

With an improving economy, the increase in government revenues (due to higher taxes) and decrease in government expenditures (as less money is spent on social programs) will likely lead to an improvement in the budget balance. An improved budget balance can mean a reduced budget deficit or an increased budget surplus, depending on the specific case.

An improved budget balance may result in lower interest rates, as the government borrows less or not at all in the case of a budget surplus. Lower interest rates encourage businesses to invest in capital projects, which stimulates demand for goods and services and leads to further economic growth. Thus, an improving economy with a better budget balance is likely to boost investment.

As investment increases, it will generally lead to an increase in imports, since businesses may need to purchase equipment, raw materials, or other capital goods from abroad. At the same time, higher consumer spending and business investment may also increase domestic production and exports, which can help offset the potential negative impact on the trade balance. In short, an improving economy can have both positive and negative effects on the trade balance. However, it's important to consider the specific context and other factors affecting the economy, such as exchange rates, trade policies, and global economic conditions, to have a more complete understanding of how the trade balance may be affected. In conclusion, an improving economy with no discretionary increase in government spending can lead to an improved budget balance, increased investment, and mixed effects on the trade balance, depending on the specific circumstances and factors at play.