It is predicted that Tourist Revenue for 2006 is 500 billion Baht or $12.2 billion USD (see 1.) if we exclude the children and business vistors then match off all the adult male and female arrivals we are left with 28% disparity of males over females arriving for holidays (see 2.) although the official TAT figures are showing this trend to be falling (see 3.) this does not indicate wether the arrivals are children or adults. So let's take a middle line and say 24% single males so now we have 500,000,000,000 Baht * 0.24 = approxmately 120bn Baht or $3bn.
Thailand's GDP for 2005 is estimated at $174bn (see 4.) so you could speculate that the attractions of Thailand to solo male vistitors contributes around 1.75% to GDP.
Now the question is where does it all go? Answers please.
DISCLAIMER. I'm not an economist and had to look up the proper definition of GDP before I even started writing this so don't accept this post as anything but pure speculation.
