Discrepancy between Business Analyst data and Census data

ScottAulen1

I'm attempting to collect demographic data for neighborhoods surrounding city parks and I'm getting conflicting data.  I've delineated the neighborhood boundaries following the census blocks but the data provided by the Census at the block level is different than what Business Analyst is generating.

Does BA use a weighted aggregation approach even if the area doesn't cut across blocks (and therefore an estimate isn't needed)?  The population count and number of households is correct pretty much every time but the rest of the data is usually off (race and age primarily).

Thanks,

ScottAulen1

Raulen,

Take a look at the below link to the 10.1 Help which details how Business Analyst summarizes data.  In the most basic sense it uses a 'centroid in or out' approach.

http://resources.arcgis.com/en/help/main/10.1/#/Data_tab/000z000000v7000000/

Regards,
Jason R.

Jason,
Thanks for the response.  I reviewed that Help page previously but I'm not sure it specifically addresses my problem.

From the Help page: "Different methods are provided to more accurately retrieve data. This is important when a trade area cuts across a demographic layer."

In this situation I'm not actually cutting across a demographic layer.  The Census provides full counts of race, age, gender demographics to the block level and the area I'm looking at is a collection of full blocks.  Since I'm looking at fairly small service areas (in some cases 6 or 7 census blocks),  I'm using the Census provided race and age breakdowns to check the accuracy of Business Analyst so I know how reliable the BA data is with regards to variables the Census doesn't provide at the block level (Household Income, Median Age, Home Value). 

What seems strange is that some of the data from BA is often exact (Total Population Count, Housing Units, Households) while other data can be fairly different (Race, Age Cohorts, Gender Percentages, Group Quarter Population) compared to the Census.