/* This is an "updated" version of the program Duration.sas. Here the last expansion is not censored. It is 120 months in duration and ended in March, 2001. What we want to see is how much the analysis of the duration of cycles pre- and post-World War II are affected by this last observation now be uncensored. */ /* This program conducts a duration analysis of the expansions of the U.S. economy from 1854 to the present. We are interested in seeing if there is any difference in the survival rates of expansions between Pre-World War II and Post-World War II and if in these two periods there exists "conditioning" variables that affect the average durations of expansions. Here we try a dummy for wars to see if wars affect the durations of expansions in the economy. */ options pagesize=60 linesize=74 nodate; data duration; input obs mon year dur war censor; IF year le 1945 THEN dum=0; ELSE dum=1; cards; 1 12 1854 30 0 0 2 12 1858 22 0 0 3 6 1861 46 1 0 4 12 1867 18 0 0 5 12 1870 34 0 0 6 3 1879 36 0 0 7 5 1885 22 0 0 8 4 1888 27 0 0 9 5 1891 20 0 0 10 6 1894 18 0 0 11 6 1897 24 0 0 12 12 1900 21 0 0 13 8 1904 33 0 0 14 6 1908 19 0 0 15 1 1912 12 0 0 16 12 1914 44 1 0 17 3 1919 10 0 0 18 7 1921 22 0 0 19 7 1924 27 0 0 20 11 1927 21 0 0 21 3 1933 50 0 0 22 6 1938 80 1 0 23 10 1945 37 0 0 24 10 1949 45 1 0 25 5 1954 39 0 0 26 4 1958 24 0 0 27 2 1961 106 1 0 28 11 1970 36 0 0 29 3 1975 58 0 0 30 7 1980 12 0 0 31 11 1982 92 0 0 32 3 1991 120 0 0 ; proc lifereg data=duration; model dur = / dist = weibull; output out=out quantiles=.1 .5 .9 std=std p=predtime; title1 'Weibull Model with no explanatory variables'; title2 'Last Observation is Censored and Included'; proc print data=out; proc lifereg data=duration; model dur = dum / dist = weibull; output out=out quantiles=.1 .5 .9 std=std p=predtime; title1 'Weibull Model with World War II Dummy'; title2 'Last Observation is Censored and Included'; proc print data=out; proc lifereg data=duration; model dur = dum war / dist = weibull; output out=out quantiles=.1 .5 .9 std=std p=predtime; title1 'Weibull Model with World War II Dummy and War Dummy'; title2 'Last Observation is Censored and Included'; proc print data=out; run;