Almost ____ percent of the global population live in low-income countries

How has the heavy reliance on cell phones by citizens created problems for survey researchers?

a. It is now more difficult to draw a sample that is random. b. It is now more difficult to build intensity measures into responses. c. It is now more difficult to place repeated callbacks. d. It is now more difficult to cluster interviews geographically.

Since World War II, which of the following areas has been the most successful developing region?

a. Latin America b. Asia c. Sub-Saharan Africa d. Middle East and North Africa