题目如下：

    Consider a market in which there are two bidders, who are seeking to acquire spectrum blocks.  Bidder j, j = 1, 2, can increase its spectrum holdings from Sj to Sj + B if it wins a block.  Its costs will fall from cj0 to cj0 – Δif it wins.  Suppose one firm starts with lower costs, i.e., c10  < c20.  

a.       Assume Bertrand competition for wireless services using this spectrum.  Who wins an auction for this block?  How much will they pay?

b.      What happens if there is Cournot competition?

c.       What happens to consumer welfare?  

d.      Should spectrum caps be imposed?

大家会做的给点提示吧。。。呜呜