Steve Doig presents "Math and Data for Business Journalism Students" during the annual 2012 Reynolds Business Journalism Seminars, hosted by the Donald W. Reynolds National Center for Business Journalism. For more information about free training for business journalists, please visit businessjournalism.org.

1. Math and Data for
Business Journalism Students
STEVE DOIG
CRONKITE SCHOOL OF JOURNALISM

2. Math and data
 Journalism students are terrified of math and think
Google answers everything.
 Business coverage demands…
 Good math skills
 Good data analysis skills
 We need to teach them how to use math to analyze
data

3. Computer-assisted Business Reporting
 Internet browser
 Spreadsheet: Microsoft Excel
 Database manager: Microsoft Access?
 Statistics: SPSS?

4. Business math
 Percentage change
 Compound interest
 Rates
 Consumer price index
 Probability
 Linear regression
 Exotica:
 Gini coefficient
 H-H index
 Benford’s Law

5. Percentage change
 Measure change over time
 NEW / OLD – 1
 or (new – old) / old
 Example: $8 million profit this year, $5 million
last year
 8/5 - 1 = 1.6 - 1 = .6, or a 60% increase
 Example: $5 million profit this year, $8 million
last year
 5/8 – 1 = .625 – 1 = - .375, or a 37.5% decrease

6. Compound interest
 Calculates the effect of interest being added to
principal over time, thus compounding the return
 Future_value = present_value * (1 + i)^n
 i = interest rate
 n = number of periods (i.e., 360 for 30 year
mortgage paid monthly)
 Many compound interest calculators on the Web:
 http://www.webmath.com/compinterest.html

7. Rates
 Allows comparisons between places/companies of
different size, or comparisons across time
 Examples: Accident rates, foreclosure rates
 Example: Jonesville has 50 of 20,000 homes in
foreclosure; Metropolis has 5,000 of 2 million in
foreclosure
 Jonesville: (60 / 20000) * 1000 = 3 homes per 1,000
 Metropolis: (4000 / 2000000) * 1000 = 2 homes per 1,000

8. Consumer price index
 Accounts for inflation; lets you compare prices over
time in constant dollars
 Price_now / cpi_now = price_then / cpi_then
 Get CPI from Bureau of Labor Statistics at
www.bls.gov/CPI/

9. CPI example: Gasoline prices
 CPI now = 226.4
 CPI in 1965 was 30.8
 Gasoline in 1965 was $0.30 per gallon.
 X / 0.30 = 226.4 / 30.8
 X = (226.4 / 30.8) * 0.30
 X = 7.35 * 0.30 = 2.21
 Therefore, gas in 1965 cost the equivalent of $2.21
per gallon in today’s dollars.

10. Probability
 Most likely use in business journalism would be to
calculate the chances of some event occuring.
 Also important in understanding p-values in
research papers.
 Example: WSJ calculated the chances of executive
stock options being granted at the best possible time
and used the results to show that dozens of
companies were backdating option grants.

11. Linear regression
 Useful for spotting outliers
 Compares how one or more independent variables
affect the value of a dependent variable
 Relationship can be seen in an X-Y scatterplot
 Time-series regression: Time is X-axis

12. Other business statistics tools
 Herfindahl-Hirschman Index: used to measure
market concentration
 Gini coefficient: measures inequality in wealth
distribution
 Benford’s Law: pattern of first digits in a collection of
numbers can reveal expense account cheating or
other man-made patterns.

13. Business data
 Web sites your students should know:
 Company Web sites for industries they cover.
 Secretaries of State Web sites for incorporation records.
http://www.nass.org
 Hoovers for company and industry information, (but it’s a
pay site). http://www.hoovers.com
 Lexis/Nexis. http://www.lexisnexis.com/

14. Searching for data
 Google (use advanced search)
 Google Finance: www.google.com/finance
 Bing
 Wolfram Alpha?

15. More websites with business data
 Edgar for SEC filings. http://www.sec.gov
 The SEC site also contains enforcement data.
http://www.sec.gov/divisions/enforce.shtml
 Bureau of Economic Analysis for updated state and
regional economy data. http://www.bea.gov
 The Bureau of Labor Statistics has even more
economic statistics. http://www.bls.gov
 The Federal Reserve has much information about
monetary policy and banking.
www.federalreserve.gov

16. Still more…
 Patent and Trademark Office is sometimes useful.
http://www.uspto.gov/
 Don’t forget the U.S. International Trade
Commission. http://www.usitc.gov/
 And the U.S. Census Bureau for demographics.
http://www.census.gov

17. U.S. Census Bureau
 It’s much more than headcounting – here’s just a
little of what business journalists can find at
census.gov:
 Economic Census – local business data collected every five
years.
 County business patterns.
 Minority- and women-owned business data.
 Building permits.
 Foreign trade exports by state.

18. Census business data index page
 http://www.census.gov/econ/www/index.html

19. Foreign trade data
 For example, from the Census Bureau, downloadable
from its Web site:

20. IRE resources
for business journalists
 http://www.ire.org/store
 Computer-Assisted Reporting: A Practical Guide,
by Brant Houston.
 The Investigative Reporter’s Handbook: A Guide
to Documents, Databases and Techniques, by
Brant Houston, Len Bruzzese and Steve Weinberg.
 Numbers in the Newsroom: Using Math and
Statistics in the Newsroom by Sarah Cohen. Part
of the IRE Beat Book series.

21. More IRE resources
 IRE Resource Center: www.ire.org/resourcecenter/
 Why reinvent the wheel?
 More than 2,000 tip sheets from IRE and NICAR
conferences, many on covering the business beat
and doing investigations.
 Searchable database of more than 20,000 stories,
both print and broadcast.

22. More IRE resources
 The NICAR Database Library at
http://data.nicar.org/
 Databases for business journalists:
 SEC administrative proceedings.
 Federal contracts data.
 Home Mortgage Disclosure Act data.
 IRS Exempt Organizations.
 SBA business loans and disaster loans.
 Federal Audit Clearinghouse Database.
 Consumer Product Safety data
 OSHA Workplace Safety data
 Wage and Hour Enforcement

23. Good math resources
 Innumeracy, by John Allen Paulos
 A Mathematician Reads the Newspaper, by Paulos
 Precision Journalism (4th ed.), by Phil Meyer
 Math Tools for Journalists, by Kathleen Woodruff
Wickham
 Cartoon Guide to Statistics, by Larry Gonick
 Statistics Every Writer Should Know (website),
www.robertniles.com/stats/

24. Excel and web data
demonstrations