Evidence of declining trend in OECD economies' income tax rates and the concern of enhancing competition in the US and the EU product markets subtly motivate the question if low income tax rates are optimal in an imperfectly competitive economy. This paper examines optimal income tax policy in a...

As in other sectors, competition in finance matters for allocative, productive and dynamic efficiency. Theory suggests, however, that unfettered competition is not first best given the special features of finance. I review these analytics and describe how to assess the degree of competition in...

This paper uses a variant of the IMF's Global Economy Model (GEM) to estimate the macroeconomic effects of Yemen's full accession into the Gulf Cooperation Council (GCC). After calibrating the model to Yemen and the GCC countries, several simulations were carried out to estimate the potential...