Michael Perelman asks, "If economics is a theory of choice, tell me how workers got to choose their working hours in the 19th C., when they had to fight for an 8 hour day?" Need Michael be told that there is a difference between economic HISTORY and economic theory -- explanation of choices people make? Of course, the choices different workers and their prospective employers made in different periods of time account for the evolution of the structure of formal and informal sectors of economies. In fact, one need not go back to the 19th century to learn this. One can discover the effects of these choices in formal and informal sectors of currently developed and less developed countries. The science of economics -- the explanation of choices people make -- is universally applicable, it has been said long ago. James Ahiakpor