带预算约束的关键词拍卖研究——基于VCG机制的视角

Keyword Auctions Research with Budget-constrained——Based on the VCG Mechanism

文章研究了带有预算约束的基于VCG机制关键词拍卖问题。之前学者的研究一般不考虑预算约束的情况,但是广告主在参与广告位竞价时,通常都会提前分配每天的预算。当广告主的支付价格达到他的预算时,就会退出此次拍卖。在VCG机制中,广告主的支付是由排位在他之后的广告主的点击率和报价的线性组合决定,所以广告主会调增报价来提高竞争对手的支付价格。文章借助带有预算约束的全局无嫉妒纳什均衡条件,给出达到均衡时的预算阈值。结果表明合理设置预算对于广告主降低成本和提高收益都有一定影响。

The paper analyses the problem of keyword auctions based on VCG mechanism with budget constraint. Previous st-udies have generally not considered the budget constraint, but advertisers who are involved in the keyword auctions usually allocate a budget for each day in advance. When advertisers pay the price to reach his budget, he will withdraw from the auction. In the VCG mechanism, the advertiser＇s payment is determined by the linear combination of the click-through rate and the price of the advertisers below him in his position. With the aid of the globally envy-free Nash equilibrium conditions, we give the budget threshold to reach equilibrium. The result shows that the reasonable setting budget has certain effect on reducing cost and improving utility of advertiser.