The Walmart Donation-Matching Gimmick/Scam

The other day, I saw an advertisement/announcement on TV stating that for every dollar you contributed to certain causes, Walmart would give two dollars (you can get the details on their web page, Walmart and the Walmart Foundation Announce up to $20 Million Toward Hurricane Harvey Relief and Recovery).  I was impressed for about thirty seconds.


Many companies have done matching-donation campaigns, whereby if you give a dollar, they will give a dollar.  It can be effective in promoting more charity by the public in some communities.  It too can be a gimmick.  Usually, they mention a cap or maximum donation that they are willing to make.  That’s where the deceit comes in.

Donation Limits

These limits sound reasonable for making sure the donor company doesn’t get in over their heads and become committed to a donation they cannot afford, but these companies have already done their homework.  For example, if the Green Cross (names in these examples have been changed just to keep you from thinking these principles have limited applicability) Christmas campaign raised ten million dollars last year and has grown as much as 20% year to year, with many years much less, an observer would have reason to be cynical if the donation-matching company has a donation limit of much less than about 15 million dollars.  Typically, the donor company will impose a limit of one or two million dollars.  I’m sure their maximum donation will be much less than the cost their advertising company would charge for similar exposure.  But when the donation-matching company imposes such a low limit, their actual final donation will always be equal to that limit, reaching the limit will NOT be advertised, and the deception of the public will begin.  The ethical thing would have to just announce they were making a simple donation of one million dollars, but if you can’t fool suckers into coughing up more money (mistakenly thinking their donation is worth twice as much to the charity), where is the sport in that.  At least this time it is for a good cause.

Walmart Doubles Down

Walmart’s new wrinkle takes this scam to the next level.  But all it means is that the owners of Walmart will reach their company donation limit sooner, and will be able to laugh at the stupidity of even more Americans.  That’s called arrogance.

Suppose that in this year’s campaign, the Green Cross is expecting ten million Americans to each donate a dollar (I’m just making the math simple).  Under their old plan, Acme Widgets would make their generous four-million-dollar-donation by announcing they will match your donation dollar-for-dollar (for up to four million of their dollars).  The first four million Americans bring in eight million dollars for the Green Cross (including Acme’s portion), but if the remaining six million Americans donate expecting to see their money go further, they are being misled.  They will bring in just six million dollars, and the Green Cross total for that year will be $14 million – a clear victory for the Green Cross (and Acme).

Under their new plan, Acme will now make their budgeted four-million-dollar-donation by announcing they will match your donation with, say, four dollars for each of yours (for up to one million of your dollars).  Now Acme reaches their limit much faster, as the first million Americans, with matching funds, help the Green Cross bring in five million dollars, while the last nine million donors (up 50% from last year) will make a contribution that they mistakenly believe is being amplified.  They will contribute only their own nine million dollars, bringing the Green Cross the same $14 million as last year, including the same amount from Acme and the same amount from the individual donors, 90% of whom were deceived.


I am not suggesting here that donating to charity is bad; quite the contrary.  I believe helping others is a good idea, an idea that is even supported in the Bible.  But there are a few things one should consider:

  1. Are you donating for the right reasons? Donations with strings attached aren’t really donations. You should not donate expecting to get anything in return (not even a reserved seat in the Hereafter). Your rewards should be internal.
  2. Similarly, don’t assume, think, or claim the recipient of your donation will place a higher value on it than you do; that’s just fraud. I’ve recently heard complaints from members of relief organizations accepting donations for victims of Hurricane Harvey about people donating expired or opened food, worn-out clothes, etc. You are not fooling anybody.
  3. On the other hand, are you giving within your means? Creating a hardship for one person to ease another – the saying for that is “Robbing Peter to pay Paul” (a Biblical reference, but not from the Bible), is not recommended. Even the airlines advise you to put the oxygen mask on yourself before tending to your children.
  4. Finally, not all charities are created equal. And not all charities are the best stewards of your money. I suggest doing your homework;
    After checking out a charity’s website, you can research potential donees at places like Charity Navigator.

What Next?

As time permits, I will be discussing some ways advertisers use math to deceive their customers.  Stay tuned.

Not Quite Clear On The Concept – Part 1

Earlier this month, the Catholic archdiocese of Newark, New Jersey, decreed that after four years of Catholic Youth Organization (CYO) basketball together, the St. John’s 5th grade team (nine boys and two girls) would not be allowed to play the last two games of the season with girls on the teamA.

First, A Little Math

The maximum of any subset cannot be greater than the set maximum.  This means that if the largest member of your weight-watching group is, say 400 pounds, then as people leave the group, that maximum will not get instantaneously larger; it could remain 400 pounds for a while, but will probably eventually get smaller.

To see the Note click here.To hide the Note click here.
The average group weight, on the other hand, could go up or down depending on how people are selected for removal from the group, but averages aren’t generally used to measure greatness.

Similarly, in sports you cannot raise the level of competition by restricting participation, meaning that you can’t say your team is the best in the universe if any member of the universe was barred from competing.  Consequently, the only logical reason for restricting membership would be to protect those members from unfair competition, meaning a team would only ban girls if they thought their boys weren’t ready for real competition. As we all know, a group’s stated reasons for an action may differ from their real reasons.

I suspect the archdiocese’s advertised reason for the decree is to protect girls from competition they can no longer handle.  But for that argument to have any credibility at all, at least two new conditions would have to be in effect:

  1. There would actually have to be a girl’s team if you want anybody to believe that their interests are really your first priority.
  2. You would protect a “weaker” group by banning the unfair competition from that group, not banning the allegedly weaker competition from the “stronger” or open group. The later option will rightly cause others to question your motives. “Who are you really protecting?”

The required game forfeitures would be further evidence of their true motive. A team is required to forfeit a game only if they won using an unfair advantage. You would not make a boxer forfeit all the matches he won with one hand tied behind his back. Obviously, the other boy’s teams not only considered the girls a threat, but most likely the sole reason for the team’s success.

A Happy Ending

On hearing the decree, the St. John’s 5th grade team immediately and unanimously decided to stick with their teammates and forfeit the season.

The girls, understandably, felt bad and offered to sacrifice themselvesA.  St. John’s athletic director honorably rejected that offer (although in the body of that article, it suggests that the league director had already cancelled St. John’s season, making the athletic director’s gesture moot.)

A new Cardinal reversed the ban and allows St. John’s to playA.

A Not-So-Happy Ending: Politics Trumps Logic

I just read about a different, but logically related case in TexasA, where a girl was taking testosterone to become a boy and wanted to compete with boys, but was required to compete as a girl and won their state wrestling championship. I’ll leave the application of principle and subsequent comments to the reader.

Simple English: The Problem With The “If” Statement

You are probably very proud of your grasp of English (unless you live in South Florida, in which case you may not give a damn).  And yet I have seen plenty of people whose lack of understanding about basic structures like the “If” statement

To see the Note click here.To hide the Note click here.
The next article in this series will discuss how misunderstandings about the conjunction “or” have caused so much trouble.
cause them to make terrible assumptions.

An Example

Suppose a young child is misbehaving to the point that the care-giving parent decrees “If you don’t knock that off, I’m going to paddle you” (This is an old example; I’m sure nobody would ever actually do that today 😉 ). As young children have been known to do, for whatever reason, the child continues with its behavior. The parent repeats the statement, with added emphasis. Nothing changes. The parent soon throws their hands up and says “wait until (your other parent) gets home”.

The parent’s first decree, like all “if” statements, had two parts; a condition and a consequence (joined by the conjunction “if”), with the understanding that if the condition is true, then the consequence will occur. It’s simple enough that even a young child can understand it. If the condition is met and the consequence is not accomplished, then the statement would be considered false. In short, the child knew that the parent was lying.

Now suppose the non-care-giving parent comes home, sees the objectionable behavior, makes a similar decree, and then the first parent points out that they had already made that decree to no avail. The child, for whatever reason, stops the objectionable behavior. To everybody’s surprise, the second parent paddles the child. Although the child and many of you listeners may think bad thoughts about this parent, one thing you can’t call him/her is a liar.

The Problem

As you can see here, the problem with the “if” statement is that is incomplete in the sense that it only addresses what happens when the condition is true, remaining completely silent to the possibility that the condition could be false.  This allows most people to make the assumption that if the condition is false, the opposite of the consequence must occur.  As the young child in our example learned, that assumption would be a mistake.

The Solution

Don’t make stupid assumptions.  As your lawyer would tell you, get it in writing.  In the above example, since the second parent didn’t make any promises about what would happen if the behavior did stop, s/he can’t be accused of lying.  If this example bothers you, I’m sure the second parent told the child afterward that the paddling was for not obeying the first parent, in which case we would be unable to judge the truthfulness of their claim until after the right set of conditions are met following some later episode of misbehavior (guesstimating any change in likelihood of that future misbehavior based on recent events  will be left as an exercise for the reader).  To lawyers, mathematicians, and the like, the parent’s explanation doesn’t matter to this case and is unnecessary.

The Blue-spotted Monks Revisited

If you are not aware of the Blue-spotted Monk problem, or haven’t seen my previous post (in which I made an error in logic), please visit The Problem Of Blue-spotted Monks.

Did you ever wonder what would happen if, as a cruel joke, it had been reported to the monks that one of them had the dreaded blue spot disease when in fact nobody was afflicted? (Am I really the only one here with a slight sinister streak?) Since none of the monks saw a spot elsewhere, they would each assume it was them that was infected and the very first day all the monks would have started to gather at the exit station. One of them, as he approached, would notice that none of the others had a blue dot and would start to chuckle to himself, thinking “these clowns can’t even count”. The others, hearing him laugh, would look around for the first time (until then they were so sure of their logical talents that they hadn’t even bothered to check), and by the time he stopped laughing the rest would have disappeared into the forest. Then it would occur to him that maybe he didn’t have a spot either. When word got back to the Guru, the laugher would be expelled for violating the “no communication” rule, but it wouldn’t affect the solution because the other monks only counted the peers that had spots on their forehead and he was never missed.

Plan B (I named this scheme in honor of B, who first put things in perspective for me. If this plan turns out to be flawed, like the last, I take full responsibility.)

When answering nature’s call in the middle of the night a few days after accepting B’s explanation about why the monks had to start at zero, it struck me that since a monk was really only concerned with three possibilities in the number of blue spots anybody has seen, modulo arithmetic might give a way to synchronize everybody’s universe or get everybody on the same page, so to speak. Plan B calls for everyone to start counting not at zero, but at the last multiple of six. For example, the person who saw ten blue dots knows that there are either:

  1. ten afflicted, not including himself, which means there are ten people who see only nine spots.  Everybody else sees ten.
  2. On the other hand, if he is blue-spotted, there are ten others like him who see ten spots and everyone else sees eleven.

Those who see nine spots know that those who see eleven don’t really exist, and those that see eleven know that the nine-seeers don’t exist. The monk that sees ten must consider each of the other two cases, but not both at once.

Under Plan B he would start counting at six, as would the possible people who saw nine, and those potential people who saw eleven. If everyone knew to start at six, the nonexistent people who saw only six spots would be gone before the second day (we’ll discuss them again shortly), and since that won’t happen, the nonexistent people seeing seven spots will leave on Day 2, etc. Our guy knows he can sleep in until Day 4, when the really possible nine-spot sighters would be scheduled to leave. If he saw spots on Day 5, he would turn himself in and everybody else would live happily ever after.

Starting the inductive thinking process, the first six possibilities start counting at zero, just like the old days. We’ll call that their landmark. As the logic countdown continues past the next landmark (which would be six in this scheme), the hard thing for me was knowing who would start using it first, or even if it was possible to make the switch if that person needed to wait for the person ahead of him (who is still using the old landmark) to make his move. I had the hardest time reconciling the notion that you needed to wait for the people ahead of you with the notion that those people don’t exist.  It turns out the solution was easier than I imagined.

In Plan B, if the number of spots you see happens to be six (or any exact multiple thereof), your dilemma is that the possible person who sees five spots started counting at zero, and won’t budge until Day 6. The guy who sees seven spots will start counting at six, and is depending on you to leave now (Day 1) or else he’s lost. Go to the exit point on Day 1. If you are not infected, there will be a very large crowd heading for the exit with no spots on their head while six people with a spot sit comfortably at home. When you spot your peers, you will avoid the crowd and head home knowing that those six afflicted people will all leave on Day 6 as scheduled, and all is right with the world. If you do have the spot, there will be six others with spots heading out that day with you while everyone else waits patiently at home. When those who originally saw seven spots wake the next morning, you will be gone and the problem will be solved.

What Next?

Lately this problem has turned into an on-again-off-again obsession for me. I first saw a different version of the problem when I was much, much younger; I didn’t figure it out for myself but the answer made perfect sense. Just a few weeks ago, I ran across the spotted monk version I discussed in my last post and again, when reading the answer, I was completely satisfied (although I felt for the commenters who couldn’t accept that it would take 100 days for 100 blue-spotted monks to turn themselves in). Days later, while on a walk contemplating even more difficult (but unrelated) relationship issues, an answer just came to me out of the blue, which is the answer I last posted. It was flawed, and when B. gave his “parallel universe” explanation for why we needed to start at zero, I thought it made even more sense than the conventional answer did, and I was again happy.  Several days after that, the modular arithmetic idea just came to me (as discussed). Then it was only my day job and other commitments that slowed me from working toward this solution. But we are not actually finished yet.

Calling All Logicians

All I’ve done so far (if I got it right this time) is to show that starting at zero is not strictly necessary.  Plan B is not the only possible plan, however.  In fact, I doubt it is the best or fastest plan (I suspect that using a smaller modulus might be helpful).  For the monks to abandon zero as their global landmark there would have to be an understanding that there was a single, logically optimal plan to replace it.  Based on my difficulties wrapping my mind around the issues so far, I don’t feel I qualify for the “perfect logicians” requirementA of this monastery.  It’s just as well; as an aging curmudgeon, that vow of silence probably wouldn’t have worked for me for very much longer anyway.  I’m hoping that the real experts will take it from here and God will finally allow me to let go of this problem.  If you do see a flaw in this scheme (a check of the references will show it would not be my first mistake on this problem), let me know. I may not be able to fix it, but in keeping with journalistic standards, I am willing to admit and advertise the error. Thank you.

Flawed Logic: The Problem Of Blue-spotted Monks

I recently ran across the Problem of the Blue-spotted Monks again at  Actually, this is a slight variation of the well-known Blue-Eyed Monk problem that can be found at, among other places. One site even called this problem “The Hardest Logic Puzzle in the World”A, but that was probably just a case of self-promotion. For today’s discussion, I chose the first version of the problem because it is simpler (we don’t have to worry about the case in which one person has red eyes). If you haven’t done so, go ahead and read the problem. We will discuss the solution in the next section.

Start With Induction

The classic answer uses mathematical inductionD to first consider the (trivial) case in which only one monk has the disease. Then they move on to the case of two monks. Their error begins in the case of three infected monks, assuming that the monks were required to start back at one in making their individual analysis.  That is wrong; in the comments section of some of the references, several people take issue with this assumption.  I believe this to be a misapplication of the induction process.  The monks have only to consider two possibilities; either they are infected or they are not. For the sake of argument, let’s say there are ten infected monks. Most of the monks will see ten fellow monks with blue spots. Ten of the monks will see nine monks with blue spots. None of the monks will see only one monk with blue spots, or just two monks with blue spots, etcetera. Those monks seeing ten spotted monks have only two possibilities – either there are ten infected monks or there are eleven. Those monks seeing nine spots need only consider the possibility that there are either nine or ten monks infected. Most of the monks, in considering their first possibility (that there are only ten infections) realize that those ten, in considering the possibility that there are only nine infections, must allow for the possibility that there are nine monks who see only eight infected monks. With the information available, nobody sees any reason to consider any other lesser possibility. Just like in the conventional solution, each monk, having two possibilities, must allow the lesser possibility (which means they are not infected) to resolve itself first before concluding that they are infected and turn themselves in. All of the monks know that the least number of infections that any of them must consider is eight, not one. The first day nothing would happen. The second day, the monks that saw only nine other spotted monks will conclude that the possibility of anyone sighting eight spotted monks was groundless, so they will all turn themselves in. The third day, those who saw ten spotted monks will all breathe a sigh of relief.

Considering The Second Possibility

Now we need to look at the big picture.  This isn’t rocket science.  Why hasn’t anybody seen the error in conventional wisdom before today?  I, like the monks, must consider the possibility that I am the one infected.  If nobody else comes forward with a confirmation of the correct answer soon, I guess I’ll be forced to turn myself in.  Please hurry.

How America’s Cup Committee Stole Victory From Kiwis

The America’s Cup, a yacht race between a single defender and a single challenger and first run in 1851 by the Royal Yacht Squadron in England for a race around the Isle of Wight, is known as the oldest international sporting trophyA. The referenced Wikipedia article provides an excellent history of the contest, and notes that the Americans held the cup continuously from the first race until 1983, the longest winning streak in the history of sport. The cup was last contested in San Francisco in 2013, but this wasn’t your father’s America’s Cup. The vessels were now 72-foot catamarans (boats with two hulls) costing well over ten million dollars each with rigid “sails” and foils (short underwater wings) that lifted the entire hull out of the water. Their top speed was over 50 miles an hour, or about twice the wind speed. The whole race was held within sight of spectators ashore and instead of taking all day, as was customary, was required to be finished in less than forty minutes to fit snugly between commercials in a one-hour television format. The series also turned out to have one of the greatest comebacks in sports. Stu Woo of the Wall Street journal did an outstanding job of explaining that competitionA. Stu failed to mention a minor change in the rules that bought the American team just enough time to complete the changes necessary to turn things around.

The 2013 America’s Cup was originally billed as a best-of-seventeen seriesA. A Best-of-T series (where T represents the total number of games to be played and is always an odd number) is widely used in sports championships, although before September 2013 I had never heard of T being larger than seven. In English (for those of you who are not sports fans) it means that the two teams will compete exactly T times (for which we will use seventeen in the rest of our examples) and then count up the points to see who won. One team can declare themselves the winner and send everybody home early if they can accumulate more of a lead than the other team can overcome in the remainder of the seventeen games. In a simple world, meaning a world without ties (in those sports that allow them) or penalty points, that would be nine wins in a best-of-seventeen series (round up(17 ÷ 2)).  Yacht racing, as the references in the first paragraph suggested, is not a simple world.  Before the series started the American team was penalized two points for cheating in an earlier round of competition, meaning that their first two wins wouldn’t really count (except to keep points away from their competitor). And although the calendar continued to list seventeen races (with the caveat “if needed” as appropriate) well into the competitionD, all of the experts were still saying that it would take nine wins for the Kiwis to take home the trophy.  The truth is that after the seventeenth race had been sailed, if New Zealand had only eight wins, then the Americans would have won nine races (17 – 8 = 9), but would only have had seven points (9 – 2 = 7), meaning that New Zealand would have still taken home the trophy.  That is what a best-of-seventeen series really means. And, as you can see near the bottom of the Final Scorecard at the end of Stu Woo’s Wall Street Journal article, that is exactly what happened.  But just before New Zealand earned their eighth victory in Race 11, the race committee declared that because the American team’s penalty shouldn’t affect New Zealand, they would still need nine wins to take home the trophy.  Shortly thereafter Races 18 & 19 were added to the schedule. As we now know, thanks to a brilliant turn-around by the American sailors, New Zealand never got that ninth win; the American’s got that point in the nineteenth and final race. Competition doesn’t get any better than that. Had the Kiwis been able to count up to seventeen or had their English been good enough to understand the meaning of “best of seventeen races”, the ending of this story may have been completely different.