The volume of non-tariffmeasures (NTMs) impacting on agricultural trade has increased considerably during the last decades. In particular, a large volume of NTMs has been established (and has potential trade effects) between North-South countries and even between countries in the Global South. Yet, the empirical literature provides contrasting and heterogeneous evidence on the effects of NTMs on trade: some studies support the ‘standards as catalysts’ view, while others favour the ‘standards as barriers’ explanation. A recent review by Santeramo and Lamonaca (2019a) underlines the large heterogeneity in estimates, and concludes that the effects of NTMs vary across types of NTM, proxies used for NTMs, levels of detail of studies, and that the estimated effects may differ due to different methodological approaches and publication processes. This special issue is dedicated to topics related to the relationships between agri-food trade and NTMs, with particular emphasis on how NTMs influence trade between African countries, for which the empirical literature is very limited (cf. Gebrehiwet et al., 2007; Scheepers et al., 2007; Shepherd and Wilson, 2013, among others). The issue contains several papers (authored by scholars from well-established institutions) that analyse, by means of very diverse approaches, the impacts of NTMs on trade of African countries. In lieu of the above-mentioned heterogeneity of results, potentially driven by heterogeneity in methodologies, the variety of approaches (e.g. meta-analysis, time series models, CGE models) enable readers to appreciate the impacts of NTMs from different perspectives. The first paper, by Santeramo and Lamonaca, opens the issue by reviewing, using a meta-analysis approach, the effects of NTMs on African agri-food trade. The broad view provided by the article allows us to conclude that for African countries the vast majority of NTMs are trade-impeding, although a marked heterogeneity is due to different methodological approaches, types of NTMs and analysed commodities. The results contrast with the broader picture described in earlier review studies and justify further specific analyses. Two papers are built on computable general equilibrium (CGE) models. The paper by Schuenemann and Kerr focuses on the effects of biofuel production, exports to the EU, and NTMs. The authors show that biofuel production stimulates both economic growth and rural development. Following a similar approach, Muchopa et al. evaluate the impact of tariff rate quota on trade and welfare. They found that the increase in exports (and in welfare) is greater with the removal of NTMs than with tariff removal. A very different approach is adopted by Liu et al., who rely on a Vector Autoregressive Model to investigate the impacts on NTMs on trade. According to their findings, they conclude that NMTs have contributed to a significant reduction in agri-food trade volume in Africa. A different perspective animates Kerr in exploring the potential effects, for genomic-based crops that are cultivated in Africa and exported to the EU, of a relatively open regulatory regime that may replace the set of NTMs currently in place. Despite the fact that the analysis is built of different assumptions and following a different methodology, the conclusions are unaltered: the NTMs are detrimental for trade of African countries. Last but not least, Bennett and Rich present an interviews-based case study for Namibia, Botswana and Norway to investigate whether market access to high-value markets for livestock products has developmental benefits. They conclude that market access to high-value markets tends to increase investments in infrastructure and capacity to meet international quality standards.

中文翻译：

---

农产品贸易和非关税措施

在过去的几十年中，影响农产品贸易的非关税措施 (NTM) 的数量大幅增加。特别是，在南北国家之间，甚至在全球南方国家之间，已经建立了大量的非关税措施（并具有潜在的贸易影响）。然而，实证文献提供了关于非关税措施对贸易影响的对比和异质证据：一些研究支持“标准作为催化剂”的观点，而其他研究则支持“标准作为壁垒”的解释。Santeramo 和 Lamonaca (2019a) 最近的一项审查强调了估计的巨大异质性，并得出结论认为，NTM 的影响因 NTM 类型、NTM 使用的代理、研究的详细程度而异，并且估计的影响可能因以下原因而有所不同不同的方法论方法和出版过程。本期特刊专门讨论与农产品贸易和非关税措施之间的关系相关的主题，特别强调非关税措施如何影响非洲国家之间的贸易，对此实证文献非常有限（参见 Gebrehiwet 等人，2007 年；Scheepers等，2007 年；Shepherd 和 Wilson，2013 年等）。本期包含多篇论文（由知名机构的学者撰写），通过非常不同的方法分析了非关税措施对非洲国家贸易的影响。代替上述结果的异质性，可能由方法的异质性驱动，各种方法（例如荟萃分析、时间序列模型、CGE 模型）使读者能够从不同的角度了解 NTM 的影响。第一篇论文，由 Santeramo 和 Lamonaca 撰写，通过使用荟萃分析方法审查非关税措施对非洲农产品贸易的影响，打开了这个问题。文章提供的广泛观点使我们能够得出结论，对非洲国家而言，绝大多数非关税措施都是阻碍贸易的，尽管由于方法方法、非关税措施的类型和分析的商品不同而存在显着的异质性。结果与早期审查研究中描述的更广泛的情况形成对比，并证明进一步具体分析是合理的。两篇论文建立在可计算一般均衡 (CGE) 模型上。Schuenemann 和 Kerr 的论文侧重于生物燃料生产、对欧盟的出口和非关税措施的影响。作者表明，生物燃料生产刺激了经济增长和农村发展。遵循类似的方法，Muchopa 等人。评估关税配额对贸易和福利的影响。他们发现，与取消关税相比，取消非关税措施带来的出口（和福利）增长更大。Liu 等人采用了一种非常不同的方法，他们依靠矢量自回归模型来研究非关税措施对贸易的影响。根据他们的调查结果，他们得出结论，NMT 导致了非洲农业食品贸易量的显着减少。一个不同的观点激励克尔探索相对开放的监管制度对在非洲种植并出口到欧盟的基于基因组的作物的潜在影响，该制度可能取代目前的一系列非关税措施。尽管分析基于不同的假设并遵循不同的方法，但结论不变：非关税措施不利于非洲国家的贸易。最后但同样重要的是，Bennett 和 Rich 对纳米比亚、博茨瓦纳和挪威进行了一项基于访谈的案例研究，以调查进入高价值畜产品市场的市场准入是否具有发展效益。他们得出的结论是，进入高价值市场的市场准入往往会增加对基础设施和能力的投资，以满足国际质量标准。