....Guys: the term "3rd World" has been out of the professional lexicon for 40 years now (I know; sometimes use the term myself!). Today, there are very specific criteria to rank the World's countries by income, vulnerability, GDP and acute poverty:
LDC (least developed countries; among them Haiti, Afghanistan, Sudan, etc).
MDC (more developed countries; among them Mexico, a prime example)
HDC (highly developed countries, or very highly developed: among them Canada, Argentina, USA, UK, Germany, France, Australia, New Zealand, Japan, etc...)
....I hope this clears things up :D