It is one that lies at the root of the rise to power of Mr. Erdogan, who has combined social conservatism with fiscally cautious economic policies to make his Justice and Development Party, or A.K.P.

FORBES: Will The New Turkey Become The Model For A New Europe?

The rise to power of Turkey has coincided with that of Prime Minister Recep Tayyip Erdogan, who has combined social conservatism with fiscally cautious economic policies to make his Justice and Development Party, or A.K.P.

FORBES: Stuff Turkey Into Your Portfolio

In a paper published last week, five economists from the Organization for Economic Cooperation and Development, working with Christopher Heady from the University of Kent in the U.K., examined the impact of tax changes in 21 developed economies over the past 34 years.

WSJ: Odds Stacked Against Latest EU Pact