A common market allows for the free movement of capital and services but large amounts of trade barriers remain. It eliminates all
quotas and
tariffs duties on imported goods from trade in goods within it. However
non-tariff barriers to trade remain, such as differences between the Member States' rules on product safety, packaging requirements and national administrative procedures. These prevent manufacturers from marketing the same goods in all member states. The objective of a common market is most often economic convergence and the creation of an integrated single market. It is sometimes considered as the first stage of a single market. The European Economic Community was the first large-scale example of a common market. A single market allows for people, goods, services and capital to move around a union as freely as they do within a single country – instead of being obstructed by national borders and barriers as they were in the past. Citizens can study, live, shop, work and retire in any member state. Consumers enjoy a vast array of products from all member states and businesses have unrestricted access to more consumers. A single market is commonly described as "frontier-free". The
European Union is the only economic union whose objective is "completing the single market". A completed, unified market usually refers to the complete removal of barriers and integration of the remaining national markets.
Complete economic integration can be seen within many countries, whether in a single
unitary state with a single set of economic rules, or among the members of a strong national
federation. For example, the sovereign states of the
United States do to some degree have different local economic regulations (e.g. licensing requirements for professionals, rules and pricing for utilities and insurance, consumer safety laws, environmental laws, minimum wage) and taxes, but are subordinate to the federal government on any matter of
interstate commerce the national government chooses to assert itself. Movement of people and goods among the states is unrestricted and without tariffs. ==Benefits and costs==