The linkage principle is a finding of auction theory. It states that auction houses have an incentive to pre-commit to revealing all available information about each lot, positive or negative. The linkage principle is seen in the art market with the tradition of auctioneers hiring art experts to examine each lot and pre-commit to provide a truthful estimate of its value.
The discovery of the linkage principle was most useful in determining optimal strategy for countries in the process of auctioning off drilling rights (as well as other natural resources, such as logging rights in Canada). An independent assessment of the land in question is now a standard feature of most auctions, even if the seller country may believe that the assessment is likely to lower the value of the land rather than confirm or raise a pre-existing valuation.
Failure to reveal information leads to the winning bidder incurring the discovery costs himself and lowering his maximum bid due to the expenses incurred in acquiring information. If he is not able to get an independent assessment, then his bids will take into account the possibility of downside risk. Both scenarios can be shown to lower the expected revenue of the seller. The expected sale price is raised by lowering these discovery costs of the winning bidder, and instead providing information to all bidders for free.