South Asia and Southeast Asia Integration Study Finds Welfare Gains, with Sectoral Winners and Adjustment Costs

A recent South Asia deep dive analysis based on a GTAP simulation suggests that deeper trade integration between South Asia and Southeast Asia could produce net welfare gains, better terms of trade, and clear sectoral shifts across the two regions. The study uses the GTAP 10 database and an underemployment-adjusted model to examine how lower tariffs and fewer non-tariff barriers might reconfigure production, trade, and labor use across regional value chains.

[IMAGE: A map of South Asia and Southeast Asia linked by trade arrows and regional value-chain nodes]

Why the Study Matters

The study asks a straightforward but important question: what happens if trade frictions between South Asia and Southeast Asia fall further than they have today? In this setting, the issue is not only whether imports become cheaper. It is also whether firms in both regions begin to source, process, and distribute goods through a wider and more integrated production network.

That distinction matters because trade integration can affect economies through several channels at once. Lower tariffs can reduce the price of final goods and intermediate inputs. Reduced non-tariff barriers can lower compliance costs, customs delays, testing duplication, and other administrative frictions. For firms, these changes can alter sourcing decisions and investment plans. For households, they can change consumer prices and employment prospects. For governments, they can influence tariff revenue and adjustment pressures.

The study is ex-ante, meaning it estimates likely effects before a policy is adopted rather than measuring observed outcomes after implementation. That is useful for policy design, but it also means the results depend on the structure of the model and on assumptions about how markets respond.

Methodology: GTAP 10 and an Underemployment Closure

The quantitative backbone of the analysis is the GTAP 10 database, a widely used global trade dataset that maps sectoral production, bilateral trade, and factor use across economies. In a general equilibrium framework, changes in trade policy are not evaluated in isolation. Instead, the model traces how price changes affect consumers, producers, and resource allocation across sectors and countries.

A key feature of the study is the use of an underemployment closure. This matters because many South Asian economies have large labor pools and persistent underemployment, especially in low-productivity segments of agriculture and informal services. In a standard full-employment setup, labor displaced from one sector is assumed to move cleanly into another without slack. By contrast, an underemployment-adjusted specification allows the model to capture labor absorption effects more realistically.

That does not remove adjustment costs. It only changes how they appear in the simulation. Rather than assuming that workers are always fully and immediately reallocated, the model can reflect partial utilization of labor, which is more relevant for labor-abundant economies. This is a more cautious way to interpret employment effects, but it still leaves open questions about skill mismatch, mobility barriers, and transition timing.

[IMAGE: A stylized general equilibrium diagram with country-sector flows and labor market linkage]

Scenario Design: Two Liberalization Paths

The study tests two policy scenarios.

Scenario 1: Ambitious Liberalization

In the first case, tariffs are reduced to zero and non-tariff barriers are cut by 25%. This represents a relatively deep integration path. It is best understood as an upper-bound stress test: if policy coordination were strong and trade frictions fell substantially, how large might the effects be?

Scenario 2: Gradual Liberalization

In the second case, tariffs in agriculture and manufacturing are reduced by half, while NTBs fall by 10%. This is a more moderate path and is likely closer to what policymakers could implement in phases. It is useful as a realism check because the gains are smaller, but so are the required political and administrative changes.

Comparing the two scenarios helps separate two questions: how large the integration gains could be in principle, and how much of those gains might be available under a more feasible reform package.

Headline Results: Positive Welfare Effects, but Not Uniformly Distributed

The main result is that the region as a whole experiences positive welfare effects under both scenarios. The model also shows an improvement in terms of trade, indicating that relative prices move in a way that can benefit participating economies, not just through higher export volumes but also through more favorable import-export price relationships.

At the aggregate level, this is a meaningful finding. Still, the headline number should not be read as a uniform improvement for every country, sector, or household group. General equilibrium results often conceal offsetting effects. A country may gain overall while some industries face stronger import competition. Export-oriented firms may benefit, while protected domestic producers may lose market share. Consumers may gain from lower prices, but government revenue can fall if tariff income declines faster than compensating tax bases expand.

The welfare result is therefore best interpreted as a net outcome after multiple adjustments, not as evidence that all participants benefit equally.

Distributional Trade-Offs and Adjustment Costs

The most important trade-off is between efficiency gains and adjustment pressure. Lower trade barriers can reallocate demand toward more competitive sectors, but the transition is not frictionless.

For workers, the gain comes from expanded demand in sectors that become more competitive or better connected to regional value chains. The cost comes from short-run displacement in sectors that lose protection or face stronger import competition. Even with underemployment in the model, the real-world transition may involve wages, hours worked, informal employment, and location-specific frictions that are not fully captured.

For governments, the fiscal effect is also mixed. Tariff reductions can improve allocation and consumer welfare, but they may reduce customs revenue, especially where tariffs still account for a meaningful share of public income. Any net fiscal benefit would depend on whether higher growth, broader tax bases, and improved trade volumes offset that decline.

At the country level, heterogeneity is likely to be substantial. Economies with stronger manufacturing bases may capture different gains from those that rely more heavily on agriculture, commodities, or protected domestic markets. Similarly, economies with better logistics and port connectivity may be able to translate policy changes into larger trade expansion than inland or infrastructure-constrained economies.

Sector Winners: Where the Gains Concentrate

The study points to manufacturing in South Asia as one of the clearest beneficiaries. That is consistent with standard trade logic. If regional barriers fall, South Asian manufacturers can access a larger market for intermediate and final goods, source cheaper inputs, and specialize more effectively. Sectors such as textiles, light engineering, processed consumer goods, and related assembly activities may be particularly responsive if they can plug into cross-border supply chains.

In Southeast Asia, the largest gains appear in extraction and processed food sectors. This pattern suggests that deeper integration is not only about finished manufactures. It also reflects the role of resource-based exports and food processing in regional trade. Lower barriers can expand demand for commodities and semi-processed goods, while better logistics and faster customs procedures can improve the competitiveness of agricultural and food products that depend on timely delivery and quality preservation.

That said, sectoral gains are not the same as sectoral stability. Resource extraction can benefit from trade expansion, but it may also be exposed to price volatility. Processed food producers can gain from larger regional demand, but they may face stricter standards and competition from imported branded products. In South Asia, manufacturing expansion could be uneven across firms: larger and more productive companies may scale up quickly, while smaller firms with weaker technology or thinner margins may struggle.

[IMAGE: A two-panel comparison graphic showing ambitious vs gradual liberalization pathways]

Southeast Asia: Gains in Resources and Food Processing, with Competitive Pressure Elsewhere

The Southeast Asia side of the story deserves particular attention because the gains are concentrated in sectors that sit at different points in the supply chain.

For extraction sectors, deeper integration can raise export opportunities, especially where regional demand for raw materials, energy-related inputs, or industrial feedstocks increases. The benefit here comes less from tariff cuts alone and more from lower trade frictions that make cross-border sales more predictable and less costly. However, extraction sectors are often capital intensive and less labor absorbing than manufacturing, so the welfare gain may not translate into broad employment gains.

Processed food is more labor-linked and can absorb more value-added domestically. If regional integration improves access to neighboring consumer markets, food processors may scale up production and diversify product lines. But these sectors are also vulnerable to sanitary and phytosanitary standards, packaging requirements, and cold-chain constraints. If those non-tariff barriers are not addressed, the gains may be smaller than the tariff changes alone would suggest.

This is where the supply-chain story becomes important. Southeast Asian producers may gain not only by exporting more final goods, but also by inserting themselves more deeply into upstream and midstream processing stages. At the same time, firms facing competition from cheaper imports may need to upgrade technology, branding, and logistics to remain competitive. In other words, integration can create winners, but it also raises the pressure to move up the value chain.

Robustness, Sensitivity, and Model Limits

The results should be read with caution for three reasons.

First, the outcomes are sensitive to key elasticities in the model, including substitution between domestic and imported goods and the responsiveness of sectoral output to price changes. If firms and consumers are less responsive than assumed, gains may be smaller. If they are more responsive, trade expansion could be larger.

Second, the model cannot fully capture adjustment frictions such as retraining delays, infrastructure bottlenecks, informal labor transitions, or political constraints on implementation. These frictions often determine whether theoretical gains materialize in practice.

Third, the results are based on a scenario design rather than observed policy change. That makes them useful for comparison, but not for definitive forecasting. The broad finding of positive welfare effects is informative, yet the magnitude and distribution of gains should be treated as conditional on the model structure and assumed policy path.

Source Note

This article is based on an ex-ante general equilibrium analysis using the GTAP 10 database and an underemployment-adjusted model, with two trade-liberalization scenarios:

• tariffs reduced to zero and NTBs reduced by 25%, and
• tariffs in agriculture and manufacturing reduced by half and NTBs reduced by 10%.

The findings are summarized from the study’s scenario outputs and should be interpreted as model-based estimates rather than observed post-policy results.

Conclusion

The study suggests that deeper integration between South Asia and Southeast Asia could produce net gains in welfare and improve terms of trade, but the benefits would not be evenly distributed. Manufacturing in South Asia and extraction plus processed food sectors in Southeast Asia appear to be among the main sectoral beneficiaries. At the same time, the analysis points to adjustment costs, fiscal trade-offs, and sensitivity to model assumptions.

Taken together, the results are best understood as a trade and supply-chain reconfiguration story. If tariffs and non-tariff barriers decline, regional production networks may become more connected, labor may be absorbed more effectively in some sectors, and specialization may deepen across borders. Whether those gains are realized in practice will depend on the pace of reform, the handling of non-tariff frictions, and the ability of firms and workers to adapt to a more integrated regional market.