Dear Donald,

I don’t know whether I should bother to continue sending you my advice. You don’t seem to be paying much attention, judging from your public actions. Nevertheless, I will try again.

This one concerns the Wall.

Now that President Peña Nieto has called your bluff about ‘making Mexico pay for it’ and called you out as a paper tiger, you have turned to Congress and asked for taxpayer money to build your wall. As a taxpayer I therefore now have a personal interest in a subject that I previously regarded as just another example of your TV-style approach to your office.

So I have gathered up a few financial statistics about this proposed addition to our national infrastructure. As a very smart person with a degree from the Wharton School of Business, this is of course what any serious businessman would be expected do in order to evaluate a deal — something you advertise yourself as being a master at.

The approved MBA tool seems to be something called a cost-benefit analysis : when there are two possible scenarios, calculate the present and future costs and benefits of each and then weigh them against each other.

First then, the Wall’s length. The total length of the U.S.–Mexico border is 1,989 miles according to Rand McNally. According to the Institute for Defense Analysis several hundred miles of this don’t need a wall; they are already sufficiently blocked by natural geology such as including rivers and cliffs, and by various already existing stretches of fencing. Estimates of how much wall is needed range from 1,200 down to as little as 700 miles to prevent those Mexican rapists from reaching our country (some of them as young as 8 years old, judging from some of the corpses found in the Arizona desert — they do start them out young, don’t they?). For the sake of this analysis I will take a 900 mile figure, provided by government sources, although on my Google map that looks optimistic.

Next, costs. You can examine on Google pictures and samples of proposed configurations put up by private construction firms on a site in Arizona (One presumes that the option of direct job creation through construction by government employees, who would be protected by the federal legislation government workers are entitled to, is too reminiscent of FDR’s approach via such initiatives as the CCC and WPA to be seriously considered by this administration.) The major differences among the samples seems dependent on whether you believe in discouragement or punishment for wall-climbers. Some models have backward slanted or smooth rounded cylindrical top edges to make getting a handhold difficult, but at least one of them has rows of sharpened spikes along the top.

It is difficult to get reliable figures for the associated costs per mile. The 8 samples currently on view cost a total of between 2.4 and 4 million dollars to erect; they are each only a few yards long, and were constructed on ideal terrain — flat and sandy. Costs for construction in mountainous places, or on rock or difficult slopes would obviously be more expensive. In 2012 you floated a total cost of 6 billion dollars. This January you raised the estimate to 18 billion. I am not aware of any major geological realignments having taken place during that interval, but perhaps the U.S. companies doing the estimating revised their thinking when they discovered that they were not dealing with Mexican pesos but with good old American corporate dollars from firms with large lobbying and campaign contribution commitments. In any case, the latest numbers I can find appear to be an (estimated, not guaranteed) 33 billion for the remaining 900 miles.

In 2015 the Institute for Defense Analysis estimated that there had been about 200,000 ‘successful’ border crossings. Consensus is that the 2016 figure was probably ‘slightly’ higher, but the 2017 figure may have been ‘slightly’ lower. Let’s accept 200,000. That means that if the wall had already been in place last year it would have cost me (as a taxpayer) $165,000 per illegal immigrant (including Hondurans and El Salvadorans) to stop them. Maintenance of the wall, including Border Patrol staffing, is estimated at something like 2 billion a year. There is no offsetting revenue to be expected from the Wall, although a few tourists might visit with selfie phones and buy a few hot dogs from (legal) Mexican vendors with stands set up at particularly photogenic spots.

So, projecting over a 10-year period and ignoring the effects of inflation, we would be deterring 2 million (10 x 200,000) potential illegals at a cost of 53 (33 + 20) billion dollars, at the end of which period we would still have the wall, and — presuming a return to political sanity in the interim — the expense of demolishing it and restoring the land to its previous condition. (I think it is doubtful, given the political implications, that we could include those costs in the original building contracts, so we would be faced with further taxpayer assessments.) That’s 53 billion divided by 2 million, or $26,500 per head.

Now let’s consider the alternative scenario. The official poverty level in this country, according to the Senate Home Security Committee, is today $14,508 for a single person, $16,460 for a family of two. To placate our humanitarian instincts let us add 20% to those numbers to allow a bit of extra breathing space to those trying to live at the edge of poverty, and guarantee new arrivals a basic federal allowance. If half the people trying to cross the border are single and the other half are married, it would cost us 100,000 x $14,508 (call it 1.5 billion) + 50,000 x $16,460 (823 million) a year. Call it two and a half billion and allow for some toys for the children. Unless my calculator app is failing me, over ten years that comes to 25 billion. We could agree to welcome those visitors, assure them that they wouldn’t starve, give them an opportunity to look for jobs or get more education (or maybe both at once), and we could do it for less than half of the cost of the Wall. And that’s without including the revenue side : we would have gained an industrious 20 million recruits to our working population, picking strawberries, mowing lawns, caring for trees, laboring on construction sites, becoming part of the skilled labor force, paying taxes (How much? Who can say?), and feeling patriotically grateful to Uncle Sam for having rescued them.

And we wouldn’t have that ugly concrete snake crawling across the landscape and requiring further outlays to demolish it.

So much for the cost-benefit analysis. You can do the Profit-and-Loss part yourself. (They taught that at Wharton, too, I’m sure.)

Now, what about the politics?

‘Legals’ — those who arrived here through the proper channels, either through luck in a visa lottery, good connections, good lawyers, crooked lawyers, or bureaucratic unpredictability, and have succeeded in establishing themselves in American communities — tend to be indignant at the idea that illegals could now be allowed to cut the line. ‘Amnesty’ to them is a dirty word — a betrayal of what they feel entitled to because they demonstrated respect for the law. They are like the brothers of the Prodigal Son, appalled by the idea that rewards are offered to the slacker for his return. Emotionally this is understandable. Practically it makes no sense.

Successful illegals who have been here for years and made useful lives for themselves and made contributions to the continuing successes of this country have histories. Presumably they first tried to enter by the legal channels, but were turned down, for whatever reasons. But, so desperate were they, and so attracted by the dream of a better life for themselves and their families, that instead of just giving up, they determined to find a way to get here, legal or illegal. They risked their lives in the desert (or in the sealed trucks of coyotes, or in the waters of the Rio Grande), some of them more than once, to make it. They have, to varying degrees, succeeded. To which group would you assign greater credit, and assign more likelihood that it would fight for a merit-based society and less income inequality? Which group would be more likely to exhibit the virtues of patriotism and ‘family values’, if that phrase hasn’t been totally drained of its meaning by the deliberate distortions of our political con men?

Looking at those success stories and the contributions their successes have made to continuing the tradition of self-reliance and hard work that we as Americans so pride ourselves on, (and all the while having to stay under the radar and get no help from the authorities) why would we now send them back? Because some of them are depriving our teen-agers of part-time summer jobs mowing lawns in our gated communities? (I doubt that our teenagers are being deprived of an opportunity to pick strawberries or clean houses.) For every illegal who has acquired a skill and succeeded in inserting himself unobtrusively into an American community and displaced a deserving native-born worker I think I could offer you at least ten others who are doing jobs that had no native-born takers who had the choice between manual and seasonal labor and the relative luxury of U.S. unemployment benefits and food stamps. (Don’t forget that the illegals couldn’t expect to receive any such aid.) Where are the crowds of young men and women of impeccable Anglo extraction with nice pink skins lined up to apply for those strawberry-picking jobs? At the unemployment benefits office, I suspect, which is next door to the one where government tax abatements and real estate development and farm subsidies are being handed out.

But I didn’t go to Wharton and I don’t look at things from a cost-benefit analysis point of view as you were trained to do. I prefer not to go by Wharton’s book, but by a different one — the one that says, “Do unto others as you would have others do unto you”.

We need a strong leader, Donald, not a paper tiger. Lead us.