Read the following excerpt from levitt and dubner's freakonomics.
in the real world, feldman learned to settle for less than 95 percent. he came to consider a company "honest" if its payment rate was above 90 percent. he considered a rate between 80 and 90 percent "annoying but tolerable." if a company habitually paid below 80 percent, feldman might post a hectoring note, like this one:
the cost of bagels has gone up dramatically since the beginning of the year. unfortunately, the number of bagels that disappear without being paid for has also gone up. don't let that continue. i don't imagine that you would teach your children to cheat, so why do it yourselves?
the excerpt serves as which type of support for the authors' argument?

Suppose you win a small lottery and have the choice of two ways to be paid: you can accept the money in a lump sum or in a series of payments over time. if you pick the lump sum, you get $2,950 today. if you pick payments over time, you get three payments: $1,000 today, $1,000 1 year from today, and $1,000 2 years from today. 1) at an interest rate of 6% per year, the winner would be better off accepting the (lump sum / payments over time), since it has the greater present value. 2) at an interest rate of 9% per year, the winner would be better off accepting the (lump sum / payments over time), since it has the greater present value. 3) years after you win the lottery, a friend in another country calls to ask your advice. by wild coincidence, she has just won another lottery with the same payout schemes. she must make a quick decision about whether to collect her money under the lump sum or the payments over time. what is the best advice to give your friend? a) the lump sum is always better. b) the payments over time are always better. c) it will depend on the interest rate; advise her to get a calculator. d) none of these answers is good advice.