Bale is the second transfer in history, Willian (not Hulk) is the most expensive sale from the RPL: ​​a new version of football inflation

Now we will explain everything.

Sports.ru has repeatedly talked about football inflation and provided the top most expensive transfers with it in mind. We used the British Credit Bureau’s TotallyMoney Index , the most popular model for calculating football inflation, which is based on the average transfer fee in the top 5 leagues in a given year.

In February, the International Center for Sports Research (CIES) presented its version of transfers over the past ten years . This is a more scientific approach that takes data from all leagues into account and creates an econometric model.

In ten years, cumulative inflation reached 116%. Central defenders rise in price the fastest

Since the 2013/14 season, football inflation has averaged 9%. If the covid pandemic had not erupted in 2020, the percentage would have been even higher – until the 2019/20 season, the average inflation rate was at 13.8%.

In just two seasons, negative inflation was observed, while in the 2018/19 season it was very small. The only powerful deflation was last season – the price tags fell by as much as 24%.

CIES separately calculated inflation rates for players of different positions and age categories. Over the past ten years, defenders have risen in price the fastest (the average rate for the central is 12.5%, for the flanks – 11.1%). Goalkeepers added in value less than outfield players – 5.2% per year.

By age, everything is more obvious: the younger the player, the faster the price tags heat up. Players under 21 become more expensive by 12.8% every year, and players over 30 are modestly more expensive by 3.6%. The 30+ category is also experiencing the biggest deflation (i.e. price reduction) since the pandemic.

Of course, the biggest football inflation is in the Premier League, with an annual rate of 12.6%. Other leagues in the top 5 are in no hurry to depreciate their own transfer budgets so quickly – inflation averaged 8.5%. The rest of the leagues live with 7.7% per year.

What is an econometric model? How accurate are these calculations?

A feature of the CIES methodology is that it is based on a statistical model, which is based on the analysis of 5244 transfers. CIES researchers Raffaele Poli, Roger Besson, and Loïc Ravenel wrote a paper on this model.

Initially, Pauly, Besson and Ravenel developed a model that would allow an objective assessment of the value of players. They picked up twelve variables: goals, assists, dribbles (all based on league strength and opposition), player age, contract remaining, playing time in the last 2 years, increase or decrease in playing time in the last season (these are two different variables), team results, the economic level of the buying club, the experience of playing for the national team, the season of the transaction.

The authors calculated that the most important indicators are the duration of the contract, age and experience. Under this model, each additional year of the contract adds 22% to the cost of selling a player. Of the club variables, the economic power of the buyer is the most important. For example, if Naby Keita had moved to Leicester in the summer of 2018 instead of Liverpool, then the amount of the transfer, according to CIES, could be 25% lower. 

This econometric model with an accuracy of at least 80% guesses the amount that corresponds to the real cost of the transfer. It turns out that 80% of transfers in football are logical (or at least mathematically explicable).

The CIES authors acknowledge the limitations associated with their model: “Econometric modeling is only possible with data that can be quantified on a large scale. This prevents us from including in the approach specific aspects that only concern a few players or clubs, or that simply cannot be quantified.