T he Transatlantic Trade and Investment Partnership (T-TIP) is a potential reciprocal free trade agree ment that the United States and the European Union (EU) are negotiating with each other. Formal negotiations commenced in July 2013. Both sides had initially aimed to conclude the negotiations in two years but have more recently expressed interest in concluding the negotiations by the end of 2016. Through the negotiation, the United States and EU seek to enhance market access and trade disciplines by addressing remaining transatlantic barriers to trade and investment in goods, services, and agriculture by negotiating a "comprehensive and high-standard" T-TIP. The goals of the negotiation aim to reduce and eliminate tariffs between the United States and EU; further open services and government procurement markets; enhance cooperation, convergence, and transparency in regulations and standards-setting processes; and strengthen and develop new rules in areas such as intellectual property rights (IPR), investment, digital trade, trade facilitation, labor and the environment, localization barriers, and state-owned enterprises. For more background information on the negotiation, see CRS Report R43387, Transatlantic Trade and Investment Partnership (T-TIP) Negotiations . Agricultural issues have been an active topic of debate in the T-TIP negotiation. The EU is an important export market for U.S. agricultural exports; but growth in U.S. agricultural exports to the EU has not kept pace with growth in trade to other U.S. markets. Agricultural imports from Europe currently exceed U.S. exports to the EU. The U.S. Department of Agriculture (USDA) reports that the EU's import tariffs on U.S. agricultural products average well above U.S. tariffs on EU agricultural products. High EU average tariffs on U.S. exports are exacerbated by the EU's non-tariff barriers to U.S. agricultural products. The United States is among the world's largest net exporters of agricultural products, averaging more than $140 billion per year (2010-2015) worldwide. The EU is a leading export market for U.S. agricultural exports—absorbing roughly 10% of exports—and is ranked as the fifth largest market for U.S. food and farm exports. In recent years, however, growth in U.S. agricultural exports to the EU has not kept pace with growth in trade to other U.S. markets, and imports from Europe currently exceed U.S. exports to the EU. In 2015, U.S. exports of agricultural products to the EU totaled $12 billion, while EU exports of agricultural products totaled $20 billion, resulting in a substantial trade deficit of nearly $8 billion for the United States. This reverses the net trade surplus in U.S. agricultural exports during the early 1990s (see Figure 1 ). Overall, compared to the value of all merchandise trade (both agricultural and non-agricultural products) between the United States and EU, agricultural trade accounts for less than 5% of total trade annually. Major U.S. agricultural exports to the EU include tree nuts, soybeans, forest products, distilled spirits, vegetable oils, wine and beer, planting seeds and tobacco, and processed fruit and wheat. Major EU agricultural exports to the United States include wine and beer, essential oils, snack foods, processed fruits and vegetables, other vegetable oils, cheese, cocoa paste/butter, live animals, nursery products, and red meats. These statistics include data for all current 28 EU member states, including the United Kingdom (covering England, Scotland, Wales, and Northern Ireland), which voted in June 2016 to exit the EU (referred to as "Brexit"). Separate trade data for the UK is provided in the section titled " Potential Impacts of Brexit ." Agricultural issues have been actively debated in the T-TIP negotiation in the context of market access for agricultural products through reduced or eliminated agricultural import tariffs but also within regulatory and intellectual property rights discussions by addressing existing non-tariff measures that may be barriers to trade. These goals are generally shared by both U.S. and EU agricultural organizations. Negotiating agricultural issues regarding regulatory and intellectual property rights issues have focused, in part, on the goals of ensuring greater transparency, harmonization, and coherence to improve cooperation and streamline the regulatory approval process among the trading partners. However, negotiating such issues is often complicated by long-standing differences between the United States and EU in terms of laws and regulations governing food safety and sanitary and phytosanitary (SPS) measures. These include disputes over the use of hormones in beef production and pathogen reduction treatment for poultry, regulations related to bovine spongiform encephalopathy (BSE, commonly known as mad cow disease) and pesticide residues on foods, animal welfare, agricultural biotechnology (genetically modified organisms, or GMOs), and the use of certain product names and brands and so-called Geographical Indications (GIs). Negotiating documents that were made public in May 2016 were said to suggest that the EU was considering making concessions to its policies and standards regarding SPS and other issues. This interpretation of events has been largely discredited by policymakers in both the United States and EU. The Office of the United States Trade Representative (USTR) maintains a website that provides a summary of U.S. objectives, negotiating round and public forum information, blog posts, facts sheets, reports, and press releases. The European Commission (EC) maintains the EU's official website, which contains negotiating proposals and fact sheets on T-TIP, covering market access, and regulatory cooperation (including SPS, technical barriers to trade [TBT], and IPR issues), among other sectors and negotiation issues. A USDA study reports that removing tariffs and tariff rate quotas (TRQs) in U.S.-EU trade could have increased U.S. agricultural exports to the EU by an estimated $5.5 billion, measured against a 2011 base year. Gains would be greatest in the U.S. livestock sectors. EU exports to the United States are also estimated to be higher by $0.8 billion compared to the study's 2011 base year ( Table 1 ). On a percentage basis, accounting for trade diversions to and from other U.S. trading partners globally, U.S. agricultural exports would have been 2% higher, while U.S. imports would have risen by 1%. By comparison, changes in both EU agricultural exports and imports are estimated to be lower. These results suggest that while agricultural trade between the United States and EU is expected to increase, the overall gains to U.S. agricultural exports could be greater than gains in EU exports, mostly attributable to expected lower overall prices for U.S. products following the removal of EU tariffs and TRQs. USDA further reports that removing selected non-tariff barriers, in addition to removing tariffs and TRQs in U.S.-EU trade, could increase U.S. agricultural exports to the EU by an additional estimated $4.1 billion annually (measured against a 2011 base year). Gains would be greatest to the U.S. livestock and produce industries. EU exports to the United States are estimated to rise by an additional $1.2 billion ( Table 1 ). On a percentage basis, U.S. agricultural exports are estimated to increase by 2% while U.S. imports rise by less than 1%. By comparison, changes in both EU agricultural exports and imports are estimated to be lower. An EU-financed a study of the economic impacts of T-TIP—measured in terms of changes in gross domestic product, employment, and production at a sectoral level for most economic sectors, including the agricultural sector—concludes that the expected impact of T-TIP on agricultural output and employment would be low compared to estimated impacts in other sectors. However, some gains are expected in U.S.-EU agricultural trade. According to the study, the estimated percentage change in U.S. exports of cereals/grains and vegetables/fruit is generally expected to be greater than that estimated for the EU, while the change in EU imports of these same product categories is expected to be lower than that for the United States. Other studies also predict an increase in U.S. exports. Other studies have reported estimated effects by economic sector, including agriculture and food sectors, for each of the EU member states. Another study by the European Parliament acknowledges that gains from tariff cuts would be limited unless regulatory and administrative barriers are also addressed. All available studies of the possible trade gains under T-TIP were completed assuming an EU membership of 28 countries, and to date none have accounted for the possible exclusion of the UK from the agreement. The potential impact of Brexit on T-TIP remains unclear, and both parties are currently evaluating the effect of Brexit on the negotiations. Technically, the referendum is only advisory for the European Parliament, and a high degree of uncertainty remains about how the separation might work, which will likely take years. Nevertheless, the exclusion of the UK from the EU could be significant in terms of the reduction of potential trade gains under the T-TIP agreement. The UK is one of the largest among the European economies and accounts for a sizeable share (about 15%) of U.S. agricultural exports to the EU each year. In 2015, U.S. exports of agricultural products to the UK totaled $1.8 billion, consisting mostly of wine and beer, fruit products, oilseed and cereal grains, and other miscellaneous edible products. EU agricultural exports to the United States totaled $0.7 billion in 2015, consisting mostly of cheese and dairy products and also beer ( Figure 2 ). These statistics exclude distilled spirits, fish and seafood, and other agricultural products.