Cheat or Honest? An Experiment

1. Cheat or Honest? An Experiment Rachel Fewster Department of Statistics

2. Catch the Cheats! • I am a fraud investigator, you are the “suspects”! • Each group picks a status: • “Honest” or “Cheat” • You can change the status that you pick if you like, but WRITE DOWN your new status on your slip (no erasing the evidence!!)

3. HONEST GROUPS: • Pick a column on the atlas sheets: • “Population”, “Area sq km”, • or “Area sq miles” • 2. Pick a start-point wherever you like • 3. Copy down 100 entries from your column: just the first two digits is enough. • E.g. for 2 691 write 2600 (don’t round it) • For 782 write 780.

4. CHEATING GROUPS: • Make up the numbers out of your head! • Again just use two digits, e.g. 530, 72000, 8800000, … • You can use the atlas sheets as a guide to range of numbers, but you must MAKE YOUR NUMBERS UP.

5. Now for the investigation! • UNDERNEATH your numbers … • Make out a TALLY LIST for FIRST DIGITS in your output:

6. 1 2 3 4 5 6 7 8 9 I I III I IIII I II III • Make out a • TALLY LIST for • FIRST DIGITS • in your output:

7. First Digit 1 2 3 4 5 6 7 8 9 1 1 3 0 1 4 1 2 3 I I III I IIII I II III 2. Rewrite the tally as numbers 3. Title “First Digit”

8. First Digit 1 2 3 4 5 6 7 8 9 1 1 3 0 1 4 1 2 3 I I III I IIII I II III • 7. Fold your paper, tear off the tallies from the rest. • 8. Write your name on the tallies section and hand in!

9. Can we catch the cheats ??? See the R demonstration at: http://www.stat.auckland.ac.nz/~fewster/benford/