2023.3.7 14:30 N602

We study the performance of fixed-price mechanisms in the bilateral trade problem. We improve the approximation ratios of welfare-optimal mechanisms in several settings. In particular, when we have only the buyer distribution, the approximation ratio is shown to be in [0.7,0.739]. It implies that in asymmetric cases with full knowledge of buyer and seller distribution, the previously best-known (1-1/e+0.0001)-approximation can be improved to 0.7. This is joint work with Zeyu Ren and Zihe Wang.