The actual data are not available yet but I can tell you, based on walking and driving around San Francisco and talking to my retail clients, that this summer has been the best tourist summer in San Francisco history.
Ordinarily the city gets about 9 million tourists. This year the number is closer to 10 million.
In asking around, I have found two explanations. I am able to get a good perspective from hoteliers, restaurateurs and auto rental agents.
The first and most important reason is the incredible global profits of corporations headquartered in the San Francisco Bay Area. Because it is virtually impossible, with double taxation in the U.S., to bring home the earnings from global operations, these global Bay Area corporations are rewarding their overseas staff with business trips for the staff and their families. They come to visit headquarters in the Bay Area.
In some cases there may be legitimate business reasons. In most cases it doesn't matter. It is a good incentive with money that can’t effectively be used for the high investment returns that are only available by re-investing in the U.S..
The second and slightly less important reason is that the English pound is almost 15% higher than it was at the beginning of the year; and the dollar is cheap for Brit's. They are coming to enjoy their monetary advantage.
San Francisco is, of course, benefiting from this unwarranted well-being. Nearly all tourists still leave San Francisco saying how dirty the city is and that it is filled with unpleasant beggars.