Which of the following happened during the recession of 2007-2009?

Experimental effects, such as the Hawthorne effect,

A) generally are not germane in quasi-experiments. B) typically require instrumental variable estimation in quasi-experiments. C) can be dealt with using binary variables in quasi-experiments. D) are the most important threat to internal validity in quasi-experiments.

Consider the game between the teens from the previous question. In addition to any pure-strategy Nash equilibrium, there is another one in mixed strategies. In it, each teen chooses to declare with probability

a. 0.52 b. 0.5 c. 0.34 d. 0.1