Formal pairs suit Writing Task 2. Neutral ones work anywhere. Informal ones belong in Speaking.
1.the global economy
formalthe economic system of the whole world
A recession in one large country can damage the global economy.
Usually with the.
2.multinational corporations
formallarge companies that operate in many countries
Multinational corporations can move production wherever labour is cheapest.
Multinationals is the short noun form.
3.lose cultural identity
neutralstop having the customs and values that make a group distinct
Some fear that small nations will lose their cultural identity as global brands spread.
Erode and preserve also collocate with cultural identity.
4.cultural diversity
formalthe existence of many different cultures together
Big cities benefit from the cultural diversity that immigration brings.
Celebrate and promote collocate with it.
5.international trade
formalthe buying and selling of goods between countries
International trade has lifted millions of people out of poverty.
Global trade is a close alternative.
6.remove trade barriers
formalend taxes or rules that make trade between countries harder
Agreements that remove trade barriers lower prices for consumers.
Lower and reduce also collocate with barriers.
7.drive economic growth
formalbe the main cause of an economy getting bigger
Exports drive economic growth in many Asian economies.
Boost and stimulate are alternatives.
8.developing countries
neutralpoorer countries that are building their economies
Foreign investment creates jobs in developing countries.
Developed countries is the contrast. Avoid third-world countries, which sounds dated.
9.exploit cheap labour
formaluse low-paid workers unfairly to cut costs
Critics say some fashion brands exploit cheap labour overseas.
Exploitation is the noun.
10.outsource jobs
neutralmove work to another company or country, usually to save money
Many banks outsource jobs in customer service to other countries.
Outsourcing is the noun.
11.promote mutual understanding
formalhelp different groups understand each other
Student exchange schemes promote mutual understanding between nations.
Foster is a formal alternative to promote.
12.traditional customs die out
neutralold practices disappear because people stop following them
In many villages, traditional customs are dying out as young people move away.
Die out is intransitive: customs die out; you cannot die them out.
13.cultural homogenisation
formalthe process of cultures becoming more alike
Global fast-food chains are often blamed for cultural homogenisation.
British spelling with -s-. A strong Band 8 phrase if used accurately.
14.an increasingly interconnected world
formala world where countries depend on each other more and more
In an increasingly interconnected world, a virus can spread to every continent within weeks.
Good opening phrase; use it once.