Models need to be changed when
a. they are based on experimental data
b. scientific understanding changes
c. they represent a phenomenon
d. they are designed to answer a question

How the environment of the northeast region affects the lifestyle of the people that live there

Opinion polls reveal that many people believe that the military buildup of the 1980s came at the expense of pressing domestic problems such as environmental pollution and deteriorating educational and transportation infrastructure. in short, people are becoming aware of

Mankiw attributes – chapter 1 and his 10 principles – differences in living standards within a countryover time and across countries at a moment in time to: a. the presence or absence of inflation and unemployment.b. the allocation of resources between private markets and the public sector.c. those that have dealt successfully with the efficiency v. equality tradeoff and those that haven’t.d. differences in productivity.e. ones that think at the margin and respond to incentives and those that don’t.