Ice Bear: The Cultural History of an Arctic Icon by Michael Engelhard

Review of Michael Engelhard\u27s Ice Bear: The Cultural History of an Arctic Icon

An Environmental History of Medieval Europe by Richard C. Hoffman

Review of Richard C. Hoffman\u27s An Environmental History of Medieval Europe

Money Demand and the Potential of Seigniorage in China.

Since 1978 China has been experiencing a strong monetary growth. However annual inflation has not exceeded 20%. One of the outcomes has been a high level of seigniorage. This paper looks for the factors that have enabled to collect this quasi-inflation-free revenue and asks the question of whether or not China can still rely on this kind of financing. For this purpose, an augmented Cagan's money demand is specified which takes into account the transitional characteristics of this economy. A Laffer type model is derived from it and provides an analysis of the dynamics of the potential of seigniorage.financial deepening, monetization, money demand, seigniorage, transitional economies, China

On the superimposition of Christoffel words

Initially stated in terms of Beatty sequences, the Fraenkel conjecture can be reformulated as follows: for a $k$-letter alphabet A, with a fixed $k \geq 3$, there exists a unique balanced infinite word, up to letter permutations and shifts, that has mutually distinct letter frequencies. Motivated by the Fraenkel conjecture, we study in this paper whether two Christoffel words can be superimposed. Following from previous works on this conjecture using Beatty sequences, we give a necessary and sufficient condition for the superimposition of two Christoffel words having same length, and more generally, of two arbitrary Christoffel words. Moreover, for any two superimposable Christoffel words, we give the number of different possible superimpositions and we prove that there exists a superimposition that works for any two superimposable Christoffel words. Finally, some new properties of Christoffel words are obtained as well as a geometric proof of a classic result concerning the money problem, using Christoffel words

The Origin of the Gaussian Initial Mass Function of Old Globular Cluster Systems

[Abridged] Evidence favouring a Gaussian initial globular cluster mass function has accumulated over recent years. We show that an approximately Gaussian mass function is naturally generated from a power-law mass distribution of protoglobular clouds by expulsion from the protocluster of star forming gas due to supernova activity, provided that the power-law mass distribution shows a lower-mass limit. As a result of gas loss, the gravitational potential of the protocluster gets weaker and only a fraction of the newly formed stars is retained. The mass fraction of bound stars ranges from zero to unity, depending on the local star formation efficiency $\epsilon$. Assuming that $\epsilon$ is independent of the protoglobular cloud mass, we investigate how such variations affect the mapping of a protoglobular cloud mass function to the resulting globular cluster initial mass function. A truncated power-law cloud mass spectrum generates bell-shaped cluster initial mass functions, with a turnover location mostly sensitive to the lower limit of the cloud mass range. We also show that a Gaussian mass function for the protoglobular clouds with a mean ${\rm log}m_G \simeq 6.1-6.2$ and a standard deviation $\sigma \lesssim 0.4$ provides results very similar to those resulting from a truncated power-law cloud mass spectrum, that is, the distribution function of masses of protoglobular clouds influences only weakly the shape of the resulting globular star cluster initial mass function. The gas removal process and the protoglobular cloud mass-scale dominate the relevant physics. Moreover, gas removal during star formation in massive clouds is likely the prime cause of the predominance of field stars in the Galactic halo.Comment: 24 pages, accepted for publication in MNRA

Inflation and the Sharing of Macroeconomic Power: A Panel Data Analysis Applied to the Chinese Provinces

Important inflation differences have been existing since 1978 across the Chinese provinces. This paper intends to connect this observation with the literature that emphasises the role of local governments in the process of excess credit supply and inflation in China. A model presents provincial credit growth and inflation as a positive function of the macroeconomic autonomy enjoyed by local authorities. The proposition is supported by a panel-data analysis applied to the Chinese provinces.local policy., credit expansion, inflation, China