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

Abstract

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.