South Africa gains from open trade, but weak currency changes the equation

South Africa's trade problem is not simply whether the economy should be more open to the world. The sharper question is whether the country can benefit from global markets when the rand itself keeps turning openness into a risk.

A new study published in Economies finds that South Africa gains from improved trade openness and long-run currency appreciation, but loses ground when the country's currency weakens or when openness is not matched by stronger import-export management.

Titled "Asymmetric Effect of Trade Openness and Exchange Rate on Economic Expansion", the study states that South Africa's policy challenge is to stay open enough to benefit from global trade while keeping the rand stable and trade policy strategic enough to protect domestic growth.

Trade and currency shifts affect growth unevenly

The study examines how South Africa's economic expansion responds to changes in trade openness and the real effective exchange rate. Trade openness is measured through the ratio of imports and exports to gross domestic product, while economic expansion is assessed through economic growth.

The authors argue that earlier studies often examined trade openness and exchange rates separately, even though currency movements can shape the benefits or risks of international trade. A stronger domestic currency can reduce the cost of imported machinery, technology and production inputs, while a weaker currency may make imports more expensive and raise uncertainty for businesses.

Using a nonlinear autoregressive distributed lag model and an error correction model, the research tested whether positive and negative movements in trade openness and exchange rates have different effects on growth. The findings confirmed an asymmetric relationship, meaning the economy does not respond in the same way to improvements and declines.

In the long run, currency appreciation was linked to higher economic growth. A 1 percent increase in the real effective exchange rate was associated with a 0.24 percent increase in economic growth. By contrast, currency depreciation was linked to a decline in economic growth of about 0.33 percent.

The finding is important because depreciation is often expected to support export competitiveness by making domestic goods cheaper for foreign buyers. In South Africa's case, the study suggests that the cost of a weaker currency may outweigh that advantage. A depreciating rand can raise the cost of imported raw materials, energy, machinery and other production inputs, placing pressure on firms and slowing expansion.

The results also show that South Africa's growth path remains exposed to currency instability. In the short run, both appreciation and depreciation shocks were found to weigh on growth, although depreciation had the larger effect. This suggests that volatility itself creates uncertainty for businesses, investors and households.

Trade openness supports growth, but unmanaged exposure carries risks

The study found that stronger trade openness supports South Africa's economic expansion over the long run. A positive shift in trade openness was associated with higher growth, while a decline in openness reduced long-term economic performance.

The authors link the benefits of trade openness to access to larger markets, imported technology, foreign investment, skills development and wider competition. These factors can improve productivity and help domestic firms participate more effectively in global markets.

The short-run findings also support the importance of openness. Positive changes in trade openness were associated with improved growth, while declines in openness hurt economic performance. This suggests that trade disruptions, restrictive policies, geopolitical shocks or weaker import-export activity can quickly affect the economy.

However, the study does not present trade openness as an automatic solution. It warns that wide openness without effective import and export management can expose South Africa to the risk of becoming a destination for low-cost imports that weaken domestic industries. In that case, the country may gain access to global markets but lose productive strength at home.

South Africa benefits from integration with the global economy, but those gains depend on the quality of trade management. Openness must support domestic production, investment and competitiveness rather than simply expand exposure to foreign goods.

The findings also reflect the country's economic structure. Because firms depend on imported inputs, raw materials, energy and capital goods, exchange-rate weakness can quickly raise production costs. That makes trade openness and exchange-rate stability closely connected. A country may remain open to global markets, but if its currency becomes unstable, the benefits of openness can weaken.

The research further found evidence of a long-run relationship among economic growth, trade openness and exchange rates. The error correction result showed that about 11 percent of short-term shocks are corrected each quarter, meaning the economy gradually returns toward its long-run path after disruption.

Why it matters for South African policy

South Africa needs both currency stability and strategic trade openness to support durable economic growth. Trade integration should remain part of the country's growth strategy, but it must be paired with stronger export-import management and measures that protect domestic productive capacity.

For monetary authorities, the findings highlight the importance of exchange-rate stability. The study shows that rand depreciation has a stronger negative effect than the positive effect linked to appreciation. Short-run exchange-rate volatility also harms growth, suggesting that businesses need a more predictable currency environment to make investment and trade decisions.

Trade policymakers need to focus on balanced openness. South Africa should remain connected to global markets, but trade policy must guard against excessive import dependence and weak domestic industrial capacity. That includes supporting export competitiveness, improving local production, strengthening value chains and ensuring that openness does not turn the domestic market into a dumping ground.

The findings also matter for industrial policy. If currency depreciation raises the cost of imported inputs, then domestic production becomes vulnerable unless the country builds stronger local supply capacity. Policies that promote technology transfer, skills development and industrial upgrading can help South Africa capture more value from trade openness.

The study's limits are also relevant for future policymaking. It focuses only on South Africa and does not include additional factors such as inflation, technology, human capital and labour mobility, all of which may affect economic expansion. Future research could test whether similar patterns hold across regional economies.