Build America Bonds (BABs) were issued by states and municipalities for twenty months as an alternative to tax-exempt bonds. The program was part of the 2009 fi scal stimulus package. The bonds are taxable to the holder, but the federal Treasury rebates 35% of the coupon payment to the issuer....

Dealers in the over-the-counter municipal bond market form trading networks with other dealers to mitigate search frictions. Regulatory audit trail data show the dealer network has a core-periphery structure with 10 to 30 hubs and over 2,000 peripheral broker-dealers in which bonds flow in a...