The December 2015 IMF Research Bulletin features a sampling of key research from the IMF. The Research Summaries in this issue look at “The Impact of Deflation and Lowflation on Fiscal Aggregates (Nicolas End, Sampawende J.-A. Tapsoba, Gilbert Terrier, and Renaud Duplay); and “Oil Exporters at the Crossroads: It Is High Time to Diversify” (Reda Cherif and Fuad Hasanov). Mahvash Saeed Qureshi provides an overview of the fifth Lindau Meeting in Economics in “Meeting the Nobel Giants.” In the Q&A column on “Seven Questions on Financial Frictions and the Sources of the Business Cycle, Marzie Taheri Sanjani looks at the driving forces of the business cycle and macroeconomic models. The top-viewed articles in 2014 from the IMF Economic Review are highlighted, along with recent IMF Working Papers, Staff Discussion Notes, and IMF publications.

This issue of the IMF Research Bulletin opens with a letter from the new editor, Rabah Arezki. The Research Summaries are a "Primer on 'Global Liquidity'" (Eugenio Cerutti, Stijn Claessens, and Lev Ratnovski); and "Trade Integration adn Business Cycle Synchronization" (Kevin Cheng, Romain Duval, and Dulani Senevirante). The Q&A column looks at "Seven Questions on the Global Housing Markets" (Hites Ahir, Heedon Kang, and Prakash Loungani). September 2014 issue of the Bulletin also includes updates on IMF Working Papers, Staff Discussion Notes, and Recommended Readings from the IMF Bookstore, as well as special announcements on new staff publications and the Fifteenth Annual Jacques Polak Research Conference. Also included is information on the latest issue of “IMF Economic Review” with a link to an article by Paul Krugman.

The paper uses a combination of micro-level datasets to document the rise of income polarization—what some have referred to as the “hollowing out” of the income distribution—in the United States, since the 1970s. While in the initial decades more middle-income households moved up, rather than down, the income ladder, since the turn of the current century, most of polarization has been towards lower incomes. This result is striking and in contrast with findings of other recent contributions. In addition, the paper finds evidence that, after conditioning on income and household characteristics, the marginal propensity to consume from permanent changes in income has somewhat fallen in recent years. We assess the potential impacts of these trends on private consumption. During 1998-2013, the rise in income polarization and lower marginal propensity to consume have suppressed the level of real consumption at the aggregate level, by about 31⁄2 percent—equivalent to more than one year of consumption.

Is there a minimum tax to GDP ratio associated with a significant acceleration in the process of growth and development? We give an empirical answer to this question by investigating the existence of a tipping point in tax-to-GDP levels. We use two separate databases: a novel contemporary database covering 139 countries from 1965 to 2011 and a historical database for 30 advanced economies from 1800 to 1980. We find that the answer to the question is yes. Estimated tipping points are similar at about 123⁄4 percent of GDP. For the contemporary dataset we find that a country just above the threshold will have GDP per capita 7.5 percent larger, after 10 years. The effect is tightly estimated and economically large.

The Fund has recognized in recent years that one cannot separate issues of economic growth and stability on one hand and equality on the other. Indeed, there is a strong case for considering inequality and an inability to sustain economic growth as two sides of the same coin. Central to the Fund’s mandate is providing advice that will enable members’ economies to grow on a sustained basis. But the Fund has rightly been cautious about recommending the use of redistributive policies given that such policies may themselves undercut economic efficiency and the prospects for sustained growth (the so-called “leaky bucket” hypothesis written about by the famous Yale economist Arthur Okun in the 1970s). This SDN follows up the previous SDN on inequality and growth by focusing on the role of redistribution. It finds that, from the perspective of the best available macroeconomic data, there is not a lot of evidence that redistribution has in fact undercut economic growth (except in extreme cases). One should be careful not to assume therefore—as Okun and others have—that there is a big tradeoff between redistribution and growth. The best available macroeconomic data do not support such a conclusion.

The IMF Research Bulletin includes listings of recent IMF Working Papers and Staff Discussion Notes. The research summaries in this issue are “Explaining the Recent Slump in Investment” (Mathieu Bussiere, Laurent Ferrara, and Juliana Milovich) and “The Quest for Stability in the Housing Markets” (Hites Ahir). The Q&A column reviews “Seven Questions on Estimating Monetary Transmission Mechanism in Low-Income Countries” (Bin Grace Li, Christopher Adam, and Andrew Berg). Also included in this issue are updates on the IMF’s official journal, the IMF Economic Review, and recommended readings from IMF Publications.

The September 2015 issue of the IMF Research Bulletin covers a range of research topics. The Research Summaries featured in this issue are “Lower for Longer: Neutral Rates in the United States” (Andrea Pescatori and Jarkko Turunen) and “Economic Principles for Resource Revenue Management” (Anthony J. Venables and Samuel Wills). The Q&A article looks at “Seven Questions on Financing for Development” (Amadou Sy) and the global development agenda. The issue also includes special announcements on the 2015 Annual Research Conference and the 2015 IMF Annual Report, as well as new IMF publications. Readers will also find a link to a top-viewed article from the “IMF Economic Review”—the IMF’s official research journal.

World Development Indicators (WDI) is the World Bank s premier annual compilation of data about development. This year s print edition and e-book have been redesigned to allow users the convenience of easily linking to the latest data on-line.

Using a newly constructed dataset on trade in services for 192 countries from 1970 to 2014, this paper shows that services currently constitute one-fourth of world trade and an increasingly important component of global production. A detailed analysis of patterns and stylized facts reveals that exports of services are not only gaining strong momentum and catching up with exports of goods in many countries, but they could also trigger a new wave of trade globalization. Research applications of the trade in service dataset on structural transformation, resilience, labor reallocation, and income distribution are outlined.