High and Volatile Treasury Yields in Tanzania: The Role of Strategic Bidding and Auction Microstructure

The observed increase in the level and volatility of Tanzania's Treasury yields in recent years against an otherwise benign macroeconomic backdrop presented a puzzle for policymakers, while raising concerns about the fiscal burden of rising debt interest payments and diversion of bank credit away from the private sector. Using evidence from bid-level data, and supported by a simple theorising of bidder incentives under unorthodox issuance practices, this paper traces the recent volatility in yields to the emergence of a sharp segmentation of the T-bill market between sophisticated financial market players (foreign-controlled banks) and a less-experienced group of investors (domestic pension funds and small banks). An important policy recommendation that emerges is that public debt managers should avoid micro-managing Treasury bill auctions by issuing amounts in excess of those offered or by dipping into oversubscribed segments of the yield curve, as such practices seriously disadvantage the less-sophisticated (but more competitive) investors vis-a-vis the more sophisticated players. Copyright (c) 2009 The Authors. Journal compilation (c) 2009 Economic Society of South Africa.