# Converting Dollar Amounts to Constant 1999 Dollars with CPI99

I have downloaded the single year files for 2013, 2014 and 2015 and want to convert 2013 and 2014 to 2015. I understand that I need to first convert 2013 and 2014 to 1999 dollars and then convert the 1999 dollars to 2015. However, when I do a crosstab of the variables "year" by "CPI99", I see that the conversion factor in the data set for 2013 is .715 and for 2014 it is .704 which do not seem consistent with the conversion factors listed on https://cps.ipums.org/cps/cpi99.shtml

If I am understanding this page correctly, for data year 2013 (income year 2012), the conversion factor would be .726 (not .715 as it shows in the dataset); and for data year 2014 (income year 2013), the conversion factor would be .715. (not .704 as I mentioned previosly)

To double check, I downloaded the single year files for 2000, 2001 and 2002, expecting the CPI for 2000 to be 1 as indicated on the conversion factor list, but when I run a crosstab again of the variables "year" by "CPI99", I get .967 for year 2000. From the conversion chart, .967 which would be for income year 2000 but not data year 2000. It seems to me data year 2000 would have a conversion of 1 since it is for income year 1999. Is this correct?

I thought the year variable indicated the data year, not the income year. Please let me know if I've misunderstood the year variable or the conversion factors listed on the website.

Many thanks!