Regional economic integration refers to cooperation between countries in a particular region to reduce trade barriers and promote economic growth. There are various types of integration arrangements, ranging from free trade areas to economic unions. Free trade areas only remove barriers between members, while customs unions also implement common external trade policies. Common markets and economic unions involve deeper integration, including coordinated economic policies and movement of labor/capital. Regional integration can increase trade and investment opportunities, but may also divert trade away from non-member nations or cause disruptions as production and employment shifts between members.