The Fed and the Question of Financial Stability: An Empirical Investigation.

This paper shows that the Fed reacts to change in spreads between corporate bond yields and government bond yields over and beyond their information content on future inflation and future activity. This result, obtained in a GMM framework, is confirmed by simulation methods. Moreover, when credit spreads are on the rise, the probability that the Fed will make a large error in forecasting output and inflation increases. In this sense, the Fed's preemptive easings - despite their short-term costs, as monetary policy may become too accommodative - are a way to take into account the downside risks to the baseline forecasts and insure the economy against increasing uncertainty and the likelihood of a very costly extreme event.Credit Spreads ; Taylor Rule ; Non-parametric estimation ; Green book forecasts.

Pre-torsors and Galois comodules over mixed distributive laws

We study comodule functors for comonads arising from mixed distributive laws. Their Galois property is reformulated in terms of a (so-called) regular arrow in Street's bicategory of comonads. Between categories possessing equalizers, we introduce the notion of a regular adjunction. An equivalence is proven between the category of pre-torsors over two regular adjunctions $(N_A,R_A)$ and $(N_B,R_B)$ on one hand, and the category of regular comonad arrows $(R_A,\xi)$ from some equalizer preserving comonad ${\mathbb C}$ to $N_BR_B$ on the other. This generalizes a known relationship between pre-torsors over equal commutative rings and Galois objects of coalgebras.Developing a bi-Galois theory of comonads, we show that a pre-torsor over regular adjunctions determines also a second (equalizer preserving) comonad ${\mathbb D}$ and a co-regular comonad arrow from ${\mathbb D}$ to $N_A R_A$, such that the comodule categories of ${\mathbb C}$ and ${\mathbb D}$ are equivalent.Comment: 34 pages LaTeX file. v2: a few typos correcte

Freshman Engineering’ Reasoning Strategies When Answering FCI Questions: A Case Study

Force Concept Inventory (FCI) is a questionnaire commonly used to assess students’ conceptual understanding of Newtonian Mechanics. We show that Cluster Analysis methods can be used to study student answers to FCI by finding their reasoning strategies on Newtonian Mechanics. Our analysis is performed to data obtained by a sample of freshman engineering students just at the beginning of their first General Physics course. The analysis takes into account the decomposition of the force concept into the conceptual dimensions suggested by test authors and successive researches. We identified groups of students with similar answering strategies, characterised by correct answers, as well as by non-correct answers showing student misconceptions/nonnormative conceptions. Such answering strategies give insights into the relationships between the student force concepts and their ability to describe and/or explain motions