Is there a directory that can give you an idea in the interest nationwide or worldwide in your business? For example, if one were an applied kinesiologist or a spiritual counselor, is there a directory which could give one an idea of what areas of the country has the most interest/demand for such things?
I hope someone else will have a better answer, but for now, I would encourage you to look at the Department of Labor and the Bureau of Labor Statistics for information on the US.
you may want to check your specific state’s department of labor - they sometimes put out state-specific occupation outlook/handbooks
as for world-wide, i would think that the complexities of comparing professions and careers across jurisdictions would make a free, off-the-shelf analysis of this unavailable. HR consulting firms (like Marsh) probably can do this for custom client requests, but not for free.
Whatever happened to that Dictionary of Occupational Titles? Called DOT codes I think. If this is kept current it will tell you what words to look for when searching for interest or demand.