Question

what identification problems result in getting causual estinates of human capital on development and are there selection bias involved?

Answer 1

Ans.
While estimating the human capital on development there could be many identification problems .. For e.g. while evaluating the return from the investment in education, skill and training , manytimes we miss to neglect the benefits which the training or education has on the productivity.  
Also we neglect the impact it has on the people working in the team as effective team player and impact on the collaboration and engagement with the team. All these factors will have positive impact on the returns from the investment in human capital but these get ignored.
Also there are many biases involved in the human capital development study like recency bias, survivorship bias or sample selection bias.