Middlemen: the visible market makers

This paper presents a search-theoretic model where middlemen can emerge endogenously to intermediate between ex ante homogeneous buyers and sellers in the presence of coordination frictions. Middlemen set price to compete in the market, and hold an inventory to provide a high matching service. I show that middlemen's inventories can mitigate trade imbalances and interact with price competition, generating an interesting tradeoff for the equilibrium price determination. The competitive limit emerges when middlemen guarantee excess demand will never occur. Conditions are characterized under which middlemen carry out the short-side principle for the market price to be Walrasian

Inflation, price competition and consumer search technology

This paper studies an (S, s) pricing model from the perspective of inflation and price competition in search markets. I present a model in which consumers'search technologies can influence firms' price setting, price dispersion, and the market structure. The result shows that although price competition among firms is more intensified in markets where consumers' search technologies are more efficient, price inflation is counter-intuitively, more likely to increase monopoly power of firms and to stimulate entry in these markets. The model also provides new empirical implications for firms' price setting behaviors

Superconducting SET with tunable electromagnetic environment

We have studied the environmental effect on superconducting single-electron transistors (S-SETs) by biasing S-SETs with arrays of small-capacitance dc SQUIDs, whose effective impedance can be varied in situ. As the zero-bias resistance of the arrays is increased, Coulomb blockade in the S-SET becomes sharper, and the gate-voltage dependence changes from e-periodic to 2e-periodic. The SQUID arrays could be used as on-chip noise filters.Comment: 2 pages, 3 embedded figures, submitted to LT23 proceedings. Error in Fig. 1 has been fixe

The Lieb-Schultz-Mattis-type filling constraints in the 1651 magnetic space groups

We present the first systematic study of the filling constraints to realize a `trivial' insulator symmetric under magnetic space group $\mathcal{M}$. The filling $\nu$ must be an integer multiple of $m^{\mathcal{M}}$ to avoid spontaneous symmetry breaking or fractionalization in gapped phases. We improve the value of $m^{\mathcal{M}}$ in the literature and prove the tightness of the constraint for the majority of magnetic space groups. The result may shed light on the material search of exotic magnets with fractionalization.Comment: 5 page, 2 figure; the version to appear in PRB (Editors' Suggestion