@unpublished {677857, title = {Is There Trade with Other Planets?}, year = {1978}, type = {facetious paper}, abstract = {If you add up countries{\textquoteright} reported trade balances, you don{\textquoteright}t get zero. Is the explanation Errors \& Omissions?\  Or does Earth run a trade deficit with other planets?\  [As cited by Krugman{\textquoteright}s "Theory of Interstellar Trade."]}, author = {Jeffrey Frankel} }