RDP 2011-01: Estimating Inflation Expectations with a Limited Number of Inflation-indexed Bonds Equation

\begin{array}{l} {\hat{x}}_{k}^{-} = e^{- K d_{k}} {\hat{x}}_{k - 1} \\ P_{x_{k}}^{-} = e^{- K d_{k}} P_{x_{k - 1}} e^{- K^{'} d_{k}} + Ω_{d_{k}} \end{array}