Previous research has separately addressed the problem of estimating risk in the presence of infrequent trading and the problem of estimating quality-adjusted returns in markets with quality variation in the observed price series. This paper simultaneously addresses both problems by applying a...

It is found that one unit root, common trend is shared by the quarterly auction price series of five frequently auctioned types of stamps. The common trends analysis provides specific, stationary linear combinations, or cointegrating portfolios, of the auction price levels. The quarterly returns...