00707nam0-22002531i-450-990003168290403321000316829FED01000316829(Aleph)000316829FED0100031682920000920d--------km-y0itay50------baitaITProductivity and Machinery InvestmentA Long Run Look 1870-1980J. Bradford De LongWorking paper seriesNBER3903De Long,J. BradfordITUNINARICAUNIMARCBK990003168290403321PaperSESSESProductivity and Machinery Investment457546UNINAING01