I study the effects of competition in the City of Helsinki bus transit
market by conducting two tests for common costs in these first-price
sealed-bid procurement auctions. I introduce bidder asymmetry and
pooling to the tests. I also discuss the need for robustness checks for
some arbitrary choices in these tests. The information environment seems
to be that of common costs. The bus companies that have garages close
to the contracted routes are influenced more by the common elements than
those whose garages are further away. More competition does not
necessarily lower procurement costs, and the City should not necessarily
implement costly policies to induce more competition. A recent merger
of two public companies cannot be criticized from a competition
perspective.