افزایش تعرفه، سهام و صادرات و رفاه اقتصاد گسترده: روش محاسبه تعادل عمومی

The current literature suggests that tariff escalation (TE) lowers the competitiveness of processing sectors. Coffee and cotton are agricultural products that face the problem of TE in developing countries, where we observe low global coffee product export shares but high global cotton textile export shares, posing a question on TE's impact on competitiveness. This paper employs a computable generalised equilibrium (CGE) modelling approach to examine the impact of TE on export shares of processed coffee and cotton textiles. We modify the standard GTAP (global trade analysis project) model to solve for global export shares and simulate the impact of eliminating TE on coffee and cotton to analyse economy-wide trade and welfare implications. Results show that TE has mixed effects on export shares, depending on the initial economic structure. Findings reveal that the elimination of TE on cotton and coffee may generate potential global gains of over US$ 0.7 billion, mainly from the cotton sector. Given the relative size of these sectors in global agriculture, the magnitude of gains is not small. This underlines the need for the policy-makers to examine, address and evaluate the prevalence of TE on a sectoral basis in ongoing WTO negotiations.

Negotiations to liberalise agriculture through modalities on agriculture market access (AMA) reflect trade liberalisation effort by World Trade Organization (WTO) member countries since the launch of the Doha round in 2001. The AMA negotiations which explicitly acknowledge tariff escalation (TE) as a relevant issue for developing countries as is the associated concept of effective protection, has been a long-recognized issue in trade policy literature (Anderson, 1998, Balassa, 1965, Greenaway and Milner, 2003 and Ruffer and Swinbank, 2003). Tariff escalation occurs when tariffs on downstream imports tend to be higher than tariffs on upstream imports such that the level of protection offered downstream, where goods are typically more processed, exceeds that upstream for less-processed intermediate goods. This is a typical problem faced by agricultural commodity exporters, who recognise that the imposition of higher import duties on processed products than on input commodities is a form of protection that impedes developing countries' efforts to move away from the production of primary agricultural products to value-added exports (Mathews, 1994). TE creates a distinct disincentive for export diversification by developing countries that do not employ resources towards higher stages of agricultural processing (Antimiani et al., 2009 and Clarke and Bruce, 2006). The disadvantage is further magnified by low world prices of primary commodities, which increases the burden on balance of payments. In this manner, TE hinders the development and expansion of processing industries in the developing countries by restricting trade-induced industrialisation, and fosters specialisation in primary exports whilst excluding processed products (Beghin and Aksoy, 2003 and Sharma, 2006). Research also shows that TE provides effective protection that leads developing countries to adopt import-substitution strategies, which retard growth and export-diversification in agricultural and manufacturing sectors (Balassa, 1968, General Agreement on Trade, Tariffs (GATT), 1982, Laird and Yeats, 1987 and Verkat, 2001). Further, the deterioration in terms of trade of developing countries is attributed mainly to declining shares of these countries in agricultural trade and price volatility of agricultural products, which indicates that TE is a significant issue in agricultural trade (Dollar, 1992, Food, Agriculture Organisation (FAO), 2004, Laird and Yeats, 1987 and Valdes, 1987). Studies report evidence of TE in both developed and developing countries (Burman et al., 2001, Organisation for Economic Cooperation and Development (OECD), 1996, Organisation for Economic Cooperation and Development (OECD), 1997, Page, 1994, Safadi and Yeats, 1993, United Nations Conference on Trade and Development (UNCTAD), 2003 and U.S. Department of Agriculture (USDA), 2001), with higher tariffs in developing than in developed countries (Laird and Yeats, 1987). Post-Uruguay Round studies, on the incidence of TE, find higher TE in bound than in applied tariffs (Elamin and Khaira, 2004), in particular, for the products on which preferential tariff applies (Bureau et al., 2007), even in developed countries (Lindland, 1997) in sectors such as rice (Wailes et al., 2004), meat, sugar, fruit, coffee, vegetable oils, beef, eggs, cereal products, tobacco, cocoa, skins, leather, dairy, sugar and concentrated fruit juice (Berkum, 2009, Cernat et al., 2002 and Food, Agriculture Organisation (FAO), 2004). For cotton textiles, TE is probably the most important distortion (Cable, 1987), particularly after the removal of MFA quotas in 2005. The recently agreed upon Framework of Modalities (on agriculture) elaborates on the general principle for reducing TE (Laborde and Martin, 2010 and World Trade Organisation (WTO), 2008), but the countries are still hesitant to fully eliminate TE. Different modelling approaches have been used to analyse the political-economic causes of TE (Cadot et al., 2004 and Khasnobis-Guha, 2003), with some focusing on the consequences in partial equilibrium (Wainio and Vanzetti, 2008), single-country CGE frameworks (Lee et al., 2008)1 and multi-country CGE models (Rae and Josling, 2003).2 Recent studies, focussing on the understanding and measurement of TE, express concerns and highlight how TE impedes the development of processing industries, particularly with regard to the agriculture and food sectors (Antimiani et al., 2011 and McCorriston and Sheldon, 2011). Bouët et al. (2012) develop a stylized theoretical world partial equilibrium model of the oilseed value chain to study the effect of TE on oilseeds. The model shows that implementing a tax on exports of raw agricultural commodity in a developing country is a rational response to tariff escalation in the developed country when the objective of the government is the sum of profits in the processing sector, farmers' surplus, final consumers' surplus in the processed sector, and public revenues. Despite a unanimous agreement among all studies about the detrimental effects of TE, none have analysed sectors with contrasting observed TE effects on export shares in a multi-country CGE framework. This paper attempts to fill this gap in the literature, by employing this approach to examine the impact of TE impacts on the competitiveness and export shares of coffee products and cotton textiles. Coffee and cotton sectors both have TE but are contrasting cases — developing countries are competitive in cotton textiles but this is not the case in coffee products. This poses a policy related question as to whether or not TE deters competitiveness of sectors producing processed commodities. Using GTAP 8 Data Base, further supplemented by various other international data sources on cotton and coffee, as well as a modified version of GTAOP model, the paper analyses economy-wide trade, export-shares and welfare implications of TE elimination on coffee and cotton sectors. The paper is structured as follows: Section 2 discusses the modelling framework, data sources, and simulation scenarios. Section 3 reports the results. Section 4 concludes.

Our results show that TE may not necessarily reduce export shares because these depend on various other factors, including tariff differences across sectors and countries as well as the structure and composition of international trade flows. At the global level, the elimination of TE results in higher global average export shares. In overall welfare terms, findings show that TE is significant in the cotton sector but not in the coffee sector. If all countries were to completely eliminate TE in the cotton and coffee sectors, most countries would benefit with potential gains ceteris paribus of over 0.7 billion US$. This is substantial, given that cotton and coffee constitute merely a part of the agricultural sector within the overall global economy. We learn several lessons from this exercise. It emerges that countries should make concerted efforts for the elimination of TE at the multilateral level. In the context of ongoing AMA negotiations, quantifying the extent of TE is of critical importance as this will enable informed decisions to be taken regarding the next steps. Our study contributes to this end, in two contrasting examples in agriculture: coffee and cotton sectors, which appear to, respectively, obey and disobey the current research conclusion that TE reduces export shares. Policy-makers ought to address and evaluate the prevalence of TE for the WTO negotiations. Whilst TE is almost always distortive, it is essential for each WTO member country to examine the relevance of TE in their policy context, by accounting for tariff differences and export shares in both the source and destination countries, to quantify its effects. It should also be noted that ongoing talks focus on deep cuts in bound tariffs are likely to generate large economic costs, given the wide gap between applied and bound tariffs. Thus, whilst it is impossible to generalise the detrimental effects of TE, it is imperative to analyse at detailed sectoral level in a multi-country framework, in order to quantify the welfare effects of TE.