Unlawful possessors of others’ land have to disgorge unjust en-richment equivalent to rent. Taiwanese courts use the formula “land value×yield rate=rent” to calculate the amount of compensation. Judges, however, never offer any solid reasoning on their determina-tions of yield rates. Using 698 randomly sampled district court cases between 2004 and 2012, we find that most court-adjudicated rents are below market rents. Using this new data set and the transaction price and lease rent database compiled by the government, we challenge the empirical foundation of several Supreme Court precedents, which dic-tate certain variables in determining the yield rate. We argue that the statute of limitations for the claim of unjust enrichment should be 15 years and the rent control stipulations are not directly applicable to un-just enrichment, either. Our policy suggestion is that courts should use the official lease rent database to compute the amount of unjust enrich-ment.