Book Reviews

We develop a first-principles approach based on many-body perturbation theory to investigate the effects of the interaction between electrons and carrier plasmons on the electronic properties of highly doped semiconductors and oxides. Through the evaluation of the electron self-energy, we account simultaneously for electron-plasmon and electron-phonon coupling in theoretical calculations of angle-resolved photoemission spectra, electron linewidths, and relaxation times. We apply this methodology to electron-doped anatase TiO2 as an illustrative example. The simulated spectra indicate that electron-plasmon coupling in TiO2 underpins the formation of satellites at energies comparable to those of polaronic spectral features. At variance with phonons, however, the energy of plasmons and their spectral fingerprints depends strongly on the carrier concentration, revealing a complex interplay between plasmon and phonon satellites. The electron-plasmon interaction accounts for approximately 40% of the total electron-boson interaction strength, and it is key to improve the agreement with measured quasiparticle spectra

Certain minimal varieties are set-theoretic complete intersections

We present a class of homogeneous ideals which are generated by monomials and binomials of degree two and are set-theoretic complete intersections. This class includes certain reducible varieties of minimal degree and, in particular, the presentation ideals of the fiber cone algebras of monomial varieties of codimension two

Agency Problems of Excess Endowment Holdings in Not-for-Profit Firms

We examine three alternative explanations for excess endowments in not-for-profit firms: (1) growth opportunities, (2) monitoring, or (3) agency problems. Inconsistent with growth opportunities, we find that most excess endowments are persistent over time, and that firms with persistent excess endowments do not exhibit higher growth in program expenses or investments. Inconsistent with better monitoring, program expenditures toward the charitable good are lower for firms with excess endowments, and CEO pay and total officer and director pay are greater for firms with excess endowments. Overall, we find that excess endowments are associated with greater agency problems

Mandatory IFRS Reporting Around the World: Early Evidence on the Economic Consequences

This paper examines the economic consequences of mandatory International Financial Reporting Standards (IFRS) reporting around the world. We analyze the effects on market liquidity, cost of capital, and Tobin\u27s q in 26 countries using a large sample of firms that are mandated to adopt IFRS. We find that, on average, market liquidity increases around the time of the introduction of IFRS. We also document a decrease in firms\u27 cost of capital and an increase in equity valuations, but only if we account for the possibility that the effects occur prior to the official adoption date. Partitioning our sample, we find that the capital-market benefits occur only in countries where firms have incentives to be transparent and where legal enforcement is strong, underscoring the central importance of firms\u27 reporting incentives and countries\u27 enforcement regimes for the quality of financial reporting. Comparing mandatory and voluntary adopters, we find that the capital market effects are most pronounced for firms that voluntarily switch to IFRS, both in the year when they switch and again later, when IFRS become mandatory. While the former result is likely due to self-selection, the latter result cautions us to attribute the capital-market effects for mandatory adopters solely or even primarily to the IFRS mandate. Many adopting countries make concurrent efforts to improve enforcement and governance regimes, which likely play into our findings. Consistent with this interpretation, the estimated liquidity improvements are smaller in magnitude when we analyze them on a monthly basis, which is more likely to isolate IFRS reporting effects