Following up on the work of Megiddo and Vazirani \cite{MV.2007}, who
determined continuity properties of equilibrium prices and
allocations for perhaps the simplest market model, Fisher's linear
case, we do the same for:
\begin{itemize}
\item
Fisher's model with piecewise-linear, concave utilities
\item
Fisher's model with spending constraint utilities
\item
Arrow-Debreu's model with linear utilities
\item
Arrow-Debreu's model with piecewise-linear, concave utilities
\end{itemize}