In order to avoid employees absconding, you should recognize them as contributors to the goals of your organization. To achieve this, pay them a good salary (which is essential to motivate anyone, including trainers or psychologists who often discuss motivation theories, improving the quality of resources, and retaining manpower), offer attractive career progression opportunities, and create a wonderful working environment.
Regarding the second question, I don't have a definitive answer because we cannot force an employee to stay once they have decided to leave. It is their fundamental right to go wherever they choose. If we consider the losses incurred by the company when a trained employee leaves without a replacement, I would classify this as a recruitment error. Just like any decision that may later result in a loss, the risks associated with manpower recruitment, selection, or retention should also be acknowledged.
Regards,
Madhu.T.K