Don't let Donald Trump's tax plans fool you. In football, trickle-down economics can be a positive thing.

In 2013, when Tottenham sold Gareth Bale to Real Madrid, the money they received was redistributed via the purchase of Paulinho, Nacer Chadli, Roberto Soldado, Etienne Capoue, Christian Eriksen, Erik Lamela and Vlad Chiriches.

So Madrid's money trickled down to Corinthians, FC Twente, Valencia, Toulouse, Ajax, Roma and Steaua Bucharest: seven clubs in six countries.

Liverpool have rejected a third Barcelona bid for Philippe Coutinho this week

Looking at the transfer activity of those clubs that summer, Tottenham's largesse then trickled further to Cerro Porteno, Coimbra, Penapolense, Ponte Preta, Londrina, Monterrey, Ajax, PEC Zwolle, Valerenga, Volendam, RKC Waalwijk, Cruzeiro, Real Zaragoza, Rubin Kazan, Vitoria Setubal, Napoli, Chelsea, Levante, Legia Warsaw, Sporting Gijon, Hercules, Red Star Belgrade, Esbjerg, Young Boys, Utrecht, Heracles Almelo, PSV Eindhoven, Udinese, FC Vaslui, Otelul Galati, FC Viitorul and CFR Cluj.

This list does not include loans or free transfers and is a minimum calculation.

It has, for instance, the £27million Tottenham paid Roma for Lamela eaten up by two deals with PSV and Udinese for Kevin Strootman and Medhi Benatia.

Yet that money could equally be attributed to other Roma business that summer benefiting Fiorentina, Arsenal, Dinamo Zagreb, Genoa and Cagliari.

There is another level below this in which the £12.1m Udinese got for Benatia, because Roma got £27m for Lamela and Tottenham £90m for Bale, then helped Botafogo, Universidad de Chile, Novara, Granada, Slaven Belupo and Inter Zapresic, but we've got to stop somewhere or be here all day.

You get the idea. In right-wing politics trickle-down economics means tax breaks for the very rich will leak down to benefit the very poor — debatable, at best — while in football it means when the very wealthy splash it about, a lot of clubs get wet.

This will certainly happen again around Neymar.

Tottenham bought seven players to replace Gareth Bale when he joined Real Madrid in 2013

Paris Saint-Germain have taken £196m of Qatar's money and presented it to Barcelona, who this week arrived ready to hand Liverpool a sizeable cut with a £90m offer for Philippe Coutinho.

Had they been successful, using the current rumour mill as a yardstick, this might have opened the way for transfer business with Southampton, or Arsenal, who in turn could have involved any combination of Manchester City, Benfica, Lazio, Atletico Madrid, Monaco, Nice, Barcelona, West Ham or Everton.

And so the trickle would continue.

But here's the problem. What if you don't fancy a trickle? Selling Coutinho might allow Liverpool to participate in a viable means of wealth redistribution but Jurgen Klopp knows it would be ruinous to his plans for this season.

From an economic perspective, trickling down works, from a professional perspective, some clubs never recover.

The sale of Luis Suarez to Barcelona in 2014 covered the purchase of Adam Lallana, Dejan Lovren and Lazar Markovic, but Liverpool have not been the same since.

Having come within a whisker of their first title win in the modern era, Liverpool have not challenged without Suarez.

It took them three seasons to return to the Champions League and cost Brendan Rodgers, the coach, his job.

There is no like-for-like replacement for Coutinho on the market this summer

Coutinho isn't as influential, but there is no like-for-like replacement on the market this summer and Klopp knows it. No wonder he is adamant that Coutinho has no price.

To sell now would be to as good as resign from the title race, perhaps even the top four, too. With Coutinho, Liverpool only came fourth last season.

Without him, it is hard to imagine they could maintain that position, no matter the strength of the summer recruits.

All economic systems have flaws, and trickle-down shares out football's wealth, but not its power.

Barcelona will find a way of passing on their Qatari windfall — and Ousmane Dembele's unexpected absence from Borussia Dortmund's training on Thursday, coinciding with a Barcelona bid, sounds ominous — but that doesn't make it good business for everybody.

Sell Coutinho and Liverpool will be £100m richer, but as impoverished as the day Klopp first walked through the door.

Rafa Benitez has compared his challenge at Newcastle to when he was Extremadura boss

Rafa fearing the worst at Newcastle

Extremadura were a minor Spanish club from the town of Almendralejo, near the Portuguese border.

Almendralejo's population is roughly the size of a capacity crowd at Pride Park, Derby, and the club spent just two of their 50 seasons in Spain's top division.

Mostly, Extremadura played in the third tier or below. In 2010, they ran out of money and folded. Extremadura UD, currently in Segunda Division B, is a different club.

So for Rafa Benitez to compare the challenge he faces at Newcastle this season to that of managing Extremadura's return to La Liga in 1998-99 is a damning indictment of Mike Ashley's regime.

If Ashley is seeking reference points from Benitez's career, surely Newcastle should be trying to emulate Valencia, a third city club who thought big and, for a time, challenged the supremacy of Spain's establishment elite.

Given limited backing — it was not as if Valencia outspent Barcelona or Real Madrid — Benitez worked wonders, winning the domestic title and the UEFA Cup in 2003-04.

Nobody is suggesting Newcastle could achieve that, certainly short-term, but for Benitez to see parallels in the task at Extremadura shows how concerned he is about the coming campaign.

Cynics might argue he is merely talking Newcastle down, so that even slender survival is viewed as achievement, but he is above that.

Unlike several recent Newcastle managers, Benitez is a hero on Tyneside. He doesn't need victory in a PR war, he needs to win football matches.

He couldn't keep Extremadura up in 1999, and if he fears history repeating that's a worry.

The debate around Caster Semenya is set to intensify as she takes part in the 800m

Sorry, Caster fails acid test

The debate around Caster Semenya will only intensify now she takes part in her strongest event, the 800m.

There are those who condemn the IAAF's attempt to limit her naturally occurring testosterone levels, arguing it is no different to height advantages, to Bjorn Borg's slow heartbeat or Michael Phelps' abnormally extended limbs.

It is, though. If Semenya were simply tall, or rangy, or had the capacity for exceptional fitness, it would come with the territory.

Supreme athletes in all fields may have outlier characteristics. We accept that.

Semenya is different because she produces the major hormone necessitating a separation of the sexes for sporting purposes.

Take testosterone away and we wouldn't need a women's event. Women do not race apart from men because of limbs or height but because of testosterone.

The leading 1500m runner at under 17 boys' level at my local athletics club — Woodford Green — would have won the women's World Championship gold in London this week by 6.78 seconds.

His name is Alex Cornwell. He set that club record in 2008 while not even the best junior runner in the country.

He didn't develop into a superstar, either, never made the national team, and his last official British ranking over 1500m as an adult was 42nd in 2014.

Yet he would have annihilated the greatest female middle distance runners in the world while just a boy. This is the difference testosterone makes.

Consider, too, that we live in a society in which people are increasingly viewed as gender fluid; in which they identify as a gender mentally as much as physically.

How do we steer women's competition through that minefield, if testosterone levels are deemed insignificant?

Of course, Semenya's road has been painful, and some aspects crassly handled. She is an innocent party in all of this.

We cannot let our sympathy, however, cloud what is a crucial judgment for the sport by ignoring the significance of testosterone production.

It is not the same as having long legs. It is the essence of the difference between men's and women's competition.

Javier Hernandez is unsure if he will celebrate if he scores against Manchester United

Don't look back, Javier

Javier Hernandez is unsure if he will celebrate if he scores on his debut against former club Manchester United on Sunday. Just what West Ham's fans will want to hear.

As the club's new £16m striker they would perhaps have been hoping for a little more by way of enthusiasm.

Hernandez was never a regular at United, while West Ham are building their forward line around him.

He may have the best intentions, but in showing respect to the club that gave him his break in English football, Hernandez may unwittingly deliver a snub.

Fans want to imagine a new signing has eyes only for them, not that he is fondly recalling an old flame.

Great Britain's underwhelming showing at the World Athletics Championships will have come as no surprise to noted psychic and national performance director, Neil Black.

Before the competition, Black announced that he knew Mo Farah and his coach Alberto Salazar were clean, having looked into their eyes.

'You get to know people,' he said. 'You look people in the eye and you have to work out and ask the question, "Do I believe there is anything that suggests otherwise?" There is nothing at all that suggests otherwise to me.'

Makes you wonder why drug testers waste all that time in laboratories when they could just get a couple of members of the Doris Stokes fan club to sort out the cheats from the good guys.

Still, you never know, there might be something in it. I've been looking at a photograph of Neil Black for some time now. I'm getting the word … sacked.

Danny Rose has signalled his displeasure with Tottenham's transfer business this summer

In a week when he was linked, again, with Manchester United, Danny Rose let it be known he wants to win trophies (United have three in two years, Tottenham none), is worth more than he is paid (United salaries are substantially higher than Tottenham's), wants his club to sign big name players (United's major arrivals this summer: Victor Lindelof, Romelu Lukaku, Nemanja Matic; Tottenham's: none) and intends one day to play up north to be nearer his mum (United north, Tottenham south).

He is not, however, going to request a transfer, meaning any potential employer will have to make an extravagant bid for him, as Manchester City did Kyle Walker.

It is almost as if he is trying to send a message to someone.

Who can that be? What can it mean?

Craig Shakespeare, who begins his first full season as Leicester manager at Arsenal on Friday night, insists there is no problem between him and Claudio Ranieri.

He also admits they have not spoken since he got the job. 'But I could pick up the phone tomorrow to ask his advice,' Shakespeare explained, 'and he could pick up the phone to me and say how it is.'

One suspects Ranieri is convinced of exactly how it is. That's why he doesn't pick up the phone.

Let's not pretend England's exit, outpassed and outclassed at the women's European Championship, wasn't coming.

There was too much empty euphoria over the bronze medal at the 2015 World Cup, and not enough attention to detail. England were 23rd of 24 teams in passing statistics.

As happened in the men's game 60 years earlier, it was a matter of time before other countries caught up and exposed that basic weaknesses.

'Nations like Holland and Spain will learn to compete physically and embrace strategy and, if we are not careful, pass England off the park as they do our men.'

And if you could read that, in this column, in July 2015, why couldn't England's coach, Mark Sampson, call it, too?

Much was made of England's physicality, athleticism and stamina again this time, but it was an overplayed hand.

Mark Sampson's England were outpassed and outclassed at the European Championship

Fitness is the simplest aspect of the game to improve. England's technique still lags behind. A third of passes went astray against France, almost half against Spain, 104 of 287 against Holland.

Between them, those three countries made just 11 defensive tackles in their matches with England. The rest, 186 successful defensive engagements, were divided between 101 clearances and 85 balls recovered.

In other words, loose play by the attacking team.

England were the highest-ranked of the semi-finalists, but were let down by poor technique. As the rest of the world improve not just their conditioning but their skill set, we must change, or nothing will.

Manchester City fans can boo the UEFA anthem at Champions League games, now the governing body have amended their rules on vocal dissent.

What choice did they have? City weren't going to stop, and UEFA couldn't sanction them every game. Plus, deep down, we all know City were right.