This paper discusses how macroeconomics can and already has begun to make use of controlled experimental methods to address the assumptions and predictions of macroeconomic models as well as to evaluate the impacts of macroeconomic policy interventions. Specific issues addressed include rational expectations and alternatives, intertemporal optimization with an application to household consumption and savings decisions and the efficacy of various monetary policies.

Common dolphinfish, Coryphaena hippurus, are an abundant, highly prized pelagic game and commercial fish, and despite their importance, information on the dolphinfish mating system is lacking. Dolphinfish are unique among pelagic fishes due to their striking sexual dimorphism, and the function of this dimorphism is currently unknown although it may reflect a very different social structure compared to monomorphic species such as tunas. A total of 58 samples, 23 females and 35 males, caught by recreational fishermen in the Southern California Bight were examined for sexual dimorphism and sexual development. Measurements of the dorsal-fin height, the linear length of the forehead, and the contour length of the forehead were performed and histological sections of the gonads were examined to determine reproductive status and to confirm sex. The morphological measurements show that the majority of males of any given size have larger head and fin features than the females. Among males, sexual dimorphism was not correlated with sexual maturity: males less than approximately 60 cm fork length, resembled females in forehead shape and dorsal-fin height, but were sexually mature. If dolphinfish exhibit a more complex mating system with large males behaving as territorial bulls and monopolizing groups of females, then fisheries managers should consider this potential social structure when developing population dynamics models and management strategies because reproduction may be affect by intense exploitation.

We evaluate the Friedman rule for optimal monetary policy in a laboratory economy based on Lagos–Wright (Journal of Economic Theory 145 (2010), 1508–24). We explore two implementations of Friedman's rule: one involving deflationary monetary policy and another where interest is paid on money. We compare the welfare consequences of the Friedman rule with two other policies: a constant money supply regime and a regime where the money supply grows at a constant k%. Counter to theory, we find that the Friedman rule is not welfare-improving, performing no better than the constant money regime. By one welfare measure, the k% money growth rate regime performs best.