The Observational Equivalence of Natural and Unnatural Rate Theories of Macroeconomics

Published in: _Recent Developments in Macroeconomics_ (Vol. 2, 1991, pp. 111-120). <br>Published in: _Journal of Political Economy_ (Vol. 84, No. 3, June 1976, pp. 631-640), https://doi.org/10.1086/260465.