Last week, Starbucks Corp. closed more than 8,000 stores in North America for an afternoon to train about 175,00 employees on combating racial bias.

The training was prompted by an incident in April at a Philadelphia Starbucks in which the manager reported to police two black men who were sitting in the store but had not yet bought anything. It turned out that the men were waiting for a friend and did not want to place an order until he arrived.