We introduce the groupwise-pivotal referral (GPR) mechanism for auctions where buyers can participate through referrals. Each buyer's type consists of a valuation and referable buyers. Unlike the second-price auction (SPA), the Vickrey-Clarke-Groves (VCG) mechanism provides referral incentives....

In the Delegated Proof-of-Stake blockchain, block producers (BP) are elected by stake-weighted vote. The supermajority of BPs can change the rule of the blockchain; thus, preventing the centralization of votes is important. We find the optimal number of votes per account (VPA) that minimizes...

In auctions with externalities, it is well-known that the core can be empty, which is undesirable both in terms of stability and fairness. Nevertheless, some auction outcome must be chosen. We separate deviations into two types: deviations by paying more and deviations by refusing to pay. In...

If buyers can only participate via referrals, referral monotonicity holds in the Vickrey-Clarke-Groves (VCG) mechanism, i.e., any buyer's payoff weakly increases as her connection (i.e., referable buyers) expands. However, if every buyer expands her connection, buyers are weakly worse off and...

We study asymmetric first-price procurements with unobserved heterogeneity and asymmetric risk-aversion. For this model, we propose a new empirical method that allows us to predict the expected procurement cost at any reserve price. Being able to perform such detailed counterfactual analysis is...

In auctions with externalities, the core can be empty, which is undesirable both in terms of stability and fairness. We show that the core is nonempty if the seller cannot deviate, as a counterpart of the result of the nonemptiness of the core when bidders cannot refuse to pay

We introduce the groupwise-pivotal referral (GPR) mechanism for auctions where buyers can participate only through referrals. Each buyer's type consists of a valuation and referable buyers. Unlike the second-price auction (SPA), the Vickrey-Clarke-Groves (VCG) mechanism provides referral...