According to conventional wisdom (and the majority of analytics), Bryce Harper is overpaid. The infamous Phillies right fielder signed a 13 year, 330 million dollar deal in the 2019 offseason. He posted 4.6 fWAR in the 2019 season, which was a surplus of 11 million dollars, but the doubt still remains. Is Harper worth the contract?
Assuming no inflation and a steady 4.5 WAR with standard age 30 regression and no significant injuries, Bryce Harper will be worth 252 million dollars. This would put his true value at around -20 million, which would indicate that he is not worth the contract. However, this obviously leaves out that he already produced a +11 surplus in 2019, and it is looking like he will do the same this season. He is currently projected at a 6.5 win pace over a 162 game season for 2020, which would give him another 27 million in surplus and would put his contract as a whole into the "success" column as he would have produced 339 million dollars in value with just 330 dished out, a +9 success of a contract. But that assumes a lot of things, and it might not be entirely correct. However, there are more factors that would make Harper even more valuable.
Harper is probably the most famous player in baseball. He was supposed to be the greatest player ever, but he didn't live up to the hype. However, he was still good enough to maintain a large fanbase, and he is also exciting as fuck. Whether it's Matt Vasgersian busting over a 450 foot bomb in a high leverage situation in the playoffs, or it's him sliding into second base with his flow hair flying everywhere, he is a dynamic personality. As a result, more fans will show up if he is playing. More people will buy his jerseys, and more people will watch the Phillies. I have absolutely no clue how to quantify this, but simply put, he produces a lot of cash value off the field.
Furthermore, inflation is a critical factor here too. I also have no clue how the MLB market will change in 13 years, but it is safe that say the 25 million now won't be worth nearly as much as 25 in 2030. For example, in 2010 Troy Tulowitzki produced 5.3 fWAR and 33 million in value. In 2019, DJ Lemahieu produced 5.4 fWAR and 42.8 million in value. The market might not improve by that much, but any money improved is value added to Bryce Harper's deal.
Finally, Harper could be much better than a 4.5 win player. 4.5 is a reasonable total, but if Harper ever cuts down on strikeouts, he could be a consistent top 5 player. As of today, he has a strikeout rate of 15% in 2020, 11 percent lower than last season. He doesn't need to maintain that clip, but if he can stay at around a 20% K rate without sacrificing power or discipline, he will be a perennial MVP candidate and will be well underpaid.