DONALD TRUMP will not follow his predecessor’s policy of releasing visitor logs for the White House. A working paper from the National Bureau of Economic Research by Jeffrey Brown and Jiekun Huang, both of the University of Illinois at Urbana-Champaign, shows what a loss that is.

They study records from Barack Obama’s administration that identify 2,286 meetings between senior executives of firms in the S&P 1500 and White House officials over a seven-year period to December 2015. The most frequent visitors were the heads of Honeywell, a conglomerate (30 trips); General Electric, another conglomerate (22); and Xerox, an office-equipment firm (21).

The study shows that a visit to the White House boosts company performance. The shares of firms whose executives secure such meetings tend to outperform those of industry peers: by 0.33% and 0.78% ten and 60 trading days, respectively, after the meetings. The more senior the host, the more pronounced the ensuing share-price outperformance: meetings with the president yield the biggest “positive abnormal returns”.

The authors suggest several reasons for this, though they stop short of proving causation. In the very short run, investors cheer news of the meetings, especially those that are widely reported and photographed. Their hopes that good will follow from the meetings are often vindicated. Compared with others in the same industry, firms with political access win more government procurement contracts. This generates on average an extra $34m in profits in the 12 months after an initial meeting.

They may also benefit from more regulatory relief. The authors point to reporting in the Wall Street Journal from 2015 that Google executives’ frequent visits to the White House under Mr Obama may have factored in a decision by the Federal Trade Commission to drop its antitrust investigation into the internet giant. Whatever the explanation, it pays to spend time at the seat of power.