When there are economical insecurities and one don't want to loose his or her job then self respect has been compromised and it leads to many other social evils and also encourages the predator to take more advantage of the victim
Mainly such things are very difficult to prove and people start making judgments about your character , that why people try to avoid to talk about such issues especially when their career , economic issues and reputation are at stake.
As a researcher try to get information in an informal talk rather than formal interviews but before that try to build some trust between you and your respondents.
True Aniqa. Although finances are an issue but even a greater problem is the fear of dishonor or "badnami" that is somehow always inflicted on the the victim and not the victimizer.
Henna - Your question itself gets to the very heart of the dynamics of workplace harassment. Sharing involves "voice", so a look at literature on "voice" in the workplace may provide you some insights. Also, the concept of "power" comes into play, and a quick google scholar search lists many papers that draw from Foucault. Also, borrowing Foucault's approach, your research question may also change its dynamic by using "how" in place of "why". From the stance of the researcher studying what I would put to you as a "vulnerable" group, the book "Researching the Vulnerable: A Guide to Sensitive Research Methods" may provide you with some clues. Here is a link to the publisher's listing: http://www.uk.sagepub.com/books/Book228231
Very good question. In the advent of Social Media/World Wide Web there is also the ability to easily destroy a persons reputation/career without question, if you are deemed a trouble maker simply for sharing the experience. Quite often co-workers will witness your experience and say nothing to avoid becoming a target themselves. Worst yet, co-workers at times become participants in the harassment coerced and non-coerced. This has accounted for a lot of Psychological Counseling that many are ashamed to discuss because yes, it does jeopardize ones livelihood along with self-respect, workplace relationships just to name a few.
But being anonymous one should be able to share the details. Don't you think its more of an avoidance technique when one doesn't want to talk about an issue?