Fashion agencies want tall models.  Commercial print agencies in major markets may have a variety of heights, and so accept shorter models.  But agencies in medium and smaller market cities generally are "hybrid" agencies which book a lot of commercial fashion work, and that sets the baseline for their needs.

Many non-fashion clients don’t much care about the height of their models.  If models were all 5’4" tall that could be just fine for them.  But there are three reasons why print agencies don’t carry many short models on the books:

1.      Even though "short" may be OK, a large height disparity between models used in a multi-person shoot is not OK.  Since most models are on the tall side, it’s more likely that another tall model will fit in.

2.      Very few clients will object to a 5’9" inch model – but many will not want to hire one at 5’3".  So the taller girls can do virtually all the commercial jobs that the short ones can, but the reverse is not true.  Shorter models can only do a fraction of the work available.

3.      In smaller markets, clients tend not to want to spend a lot of money on models.  If they need taller models, they probably need to use an agency to find them.  But if short models will work for them, as likely as not they will use family, friends and company employees, who are readily available in heights less than 5’8" (women) and 5’11" (men).  Agencies know that too, and they don’t try to compete with the client’s niece.

Agencies don’t want a lot of models that aren’t getting much (or any) work – they would much rather have all of their models working as much as possible.  So they want to sign models that can work in as much of the market for their type as possible.  And that means taller models.