Collins, H. M., (2003) `Lead Into Gold: The Science of Finding Nothing', Studies in History and Philosophy of Science, 34, 4, 661-691
Upper limits can be published before gravitational wave detectors are sufficiently sensitive to report positive results. In fact, upper limits can be set with devices of arbitrary insensitivity. For example, the fact that the keyboard of your computer is not palpably vibrating sets a limit on the proximity of inspiralling binary neutron stars of about 100 kilometers.
Such an upper limit provides too little novel information to be scientifically interesting and is so undemanding to set that it is not technologically interesting. The sociological question is `When does an upper limit deliver enough new information or reveal enough technological virtuosity to be worth publishing?'
The answer to the question depends on the audience. The general public are rarely interested in upper limits while physicists and astrophysicists are interested only in very low upper limits. Gravitational wave scientists and funders, however, are interested in relatively uninformative upper limit so long as they demonstrate technological virtuosity.
The argument is illustrated with a case study -- the setting and publishing of an upper limit emerging from the Caltech 40 meter interferometer.