The top 50 economies of the world in 2050

#1 China $25.3 tn (apparently includes Hong Kong, Macau and Taiwan)
#2 United States $22.3 tn
#3 India $8.1 tn
#4 Japan $6.4 tn
#5 Germany $3.7 tn
#6 United Kingdom $3.6 tn
#7 Brazil $3.0 tn
#8 Mexico $2.8 tn
#9 France $2.8 tn
#10 Canada $2.3 tn
#11 Italy $2.2 tn
#12 Turkey $2.1 tn
#13 South Korea $2.1 tn
#14 Spain $2.0 tn
#15 Russia $1.9 tn
#16 Philippines $1.7 tn
#17 Indonesia $1.5 tn
#18 Australia $1.5 tn
#19 Argentina $1.5 tn
#20 Egypt $1.2 tn
#21 Malaysia $1.2 tn
#22 Saudi Arabia $1.1 trillion
#23 Thailand $856 bn
#24 Netherlands $798 bn
#25 Poland $786 bn
#26 Peru $735 bn
#27 Iran $732 bn
#28 Colombia $725 bn
#29 Switzerland $711 bn
#30 Pakistan $675 bn
#31 Bangladesh $673 bn
#32 Chile $592 bn
#33 Venezuela $558 bn
#34 Algeria: $538 bn
#35 South Africa $529 bn
#36 Austria $520 bn
#37 Nigeria $515 bn
#38 Sweden: $507 bn
#39 Belgium: $481 bn
#40 Ukraine: $462 bn
#41 Vietnam: $451 bn
#42 Singapore: $441 bn
#43 Greece: $424 bn
#44 Israel: $402 bn
#45 Ireland: $386 bn
#46 Romania: $377 bn
#47 United Arab Emirates: $360 bn
#48 Norway: $352 bn
#49 Czech Republic $342 billion
#50 Portugal: $336 billion

Source: http://www.businessinsider.com/these-economies-will-dominate-the-world-in-2050-2012-1#