The National Economic Council is a much different type of operation. It’s a talking shop and influence sorter. As such, it is perfect for habitués of what used to be a secretive private partnership. It doesn’t have a large workforce of far-flung offices to manage. The director doesn’t have to be bothered much with operations, personnel, ribbon-cuttings, and pointless meetings. The job is twofold. First, the NEC director serves as one of the administration’s private-sector whisperers—talking to CEOs, drumming up outside support for policies, providing comfort to executives who might be concerned about the president’s policies and behavior. Second, the director functions as a sort of traffic cop and counselor for the conflicting power centers of policy and analysis within the administration. The job consists largely of sitting in very nice conference rooms, entertaining visitors seeking favors, attending high-end conferences, cajoling peers, participating in phone calls, and leaking selectively to favored press.
Source : http://www.slate.com/articles/business/moneybox/2016/12/why_trump_keeps_hiring_goldman_sachs_bankers.html