Jonathan Donier edited section_Discrete_Auctions_and_Price__.tex  almost 9 years ago

Commit id: 60637ef06371391a5f72b506eb675bf4fc5a2916

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\int_{y^*}^\infty \d y \rho^{\text{st.}}_{D}(y) = \int_{-\infty}^{y^*} \d y \rho^{\text{st.}}_{S}(y) \equiv v^*,  \end{equation}  where $v^*$ is the volume exchanged during the auction. For the simple exponential case above, this equation can be readily solved as:   \be \begin{equation}  \label{eq:lin-imp}\nonumber y^* = \frac{1}{2\mu} \ln \frac{\Omega_+}{\Omega_-},  \end{equation}  with a clear interpretation: if the new buy order intentions accumulated since the last auction happen to outsize the new sell intentions during the same period, the auction price will exceed the fundamental price,  

The main point of the present section is that when the inter-auction time is large enough, each auction clears an equilibrium supply with an equilibrium demand, with very simple and predictable outcomes. This corresponds to the quasi-static dynamics discussed in item 2., Section ~\ref{sec:eco}, and to the standard representation of market dynamics in the Walrasian context, since in this case only the long-term properties of supply and demand matter and the whole transients are discarded. The next section will depart from this limiting case, by introducing a finite inter-auction time such that the transient dynamics of supply and demand becomes a central feature in the theory.