Gravity equations have been widely used to infer trade  ow effects of various institutional arrangements. We show that estimated gravity equations do not have a theoretical foundation. This implies both that estimation suffers from omitted variables bias and that comparative statics analysis is unfounded. We develop a method that (i) consistently and efŽ ciently estimates a theoretical gravity...

W. Yang,1 A. J. Akey,2 L. A. Smillie,1 J. P. Mailoa,3 B. C. Johnson,4 J. C. McCallum,4 D. Macdonald,5 T. Buonassisi,3 M. J. Aziz,2 and J. S. Williams1 1Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601, Australia 2Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA 3Massachusetts Institute of Te...

Opponents of explicit in‡ation targeting (including ex-Chairman Greenspan) have argued that a commitment to a numerical in‡ation target reduces the policy’s ‡exibility, and may hence increase output volatility. Our paper demonstrates that this claim may fail to account for the anchoring e¤ect of explicit targets on expectations and wages (that has been established empirically in various studies...

Abstract This paper presents a novel unsupervised abstractive summarization method for opinionated texts. While the basic variational autoencoder-based models assume unimodal Gaussian prior latent code of sentences, we alternate it with recursive mixture, where each mixture component corresponds to topic sentence and is mixed by tree-structured distribution. By decoding component, generate sent...

Abstract This article presents a bibliographic review of the gravitational model in international trade from when it was first associated with Newton's law universal gravitation. Firstly, I will introduce concept gravity commerce as originally intended by Isard (Q J Econ 68(2):305–320, 1954) relation to Tinbergen and Tobler’s approaches. Secondly, analyse theoretical roots economics according s...

In their struggle against targeting rules, however, McCallum and Nelson seem to face an uphill battle. There is now a rapidly growing literature by many authors that successfully applies targeting rules to monetary policy analysis. This literature includes recent contributions by Benigno and Benigno (2003), Benigno and Woodford (2004a,b), Cecchetti (1998, 2000), Cecchetti and Kim (2004), Evans ...

The McCallum Projection for Cylindrical Algebraic Decomposition (CAD) produces a smaller projection factor set than previous projections, however it does not always produce a sign-invariant CAD for the set of input polynomials. Problems may arise when a (k + 1)-level projection factor vanishes identically over a k-level cell. According to McCallum’s paper, when this happens (and k+1 is not the ...

Effect of Serum Chloride on Mortality in Hypertensive Patients To the Editor: I have read with interest the large and long follow-up study by McCallum et al1 concerning the risk of low serum chloride on the mortality in 12 968 patients with hypertension. They concluded that an increase of the serum chloride by 1 mEq/L was associated with a 1.5% reduction of the all-cause mortality, cardiovascul...