CERN estimates that the High-Luminosity Large Hadron Collider (HL-LHC), an upgrade to the existing LHC, could generate about CHF 1.8 in societal benefits for every CHF 1 invested, compared with a future without the upgrade. That is a modeled social return, not revenue CERN receives, and it depends on assumptions about what the LHC would do without the upgrade.
The estimate also leaves out the intrinsic value of future scientific discoveries. It counts economic and social benefits that the analysis attempts to measure, rather than putting a price on new physics.
What the model compares
In the no-upgrade scenario, the existing LHC continues under ordinary maintenance until around 2030, when data-taking ends. The scenario assumes staff are redeployed and the tunnel is made safe but left idle. The analysis credits the HL-LHC only with benefits that differ from this alternative future, not with every benefit associated with CERN or the LHC.
That comparison is the key to understanding the CHF 1.8 estimate. It is an incremental benefit-to-cost ratio: the model weighs the additional social benefits attributed to the upgrade against its investment costs.
How the benefits are valued
The largest estimated benefit channel is training for early-career researchers. The analysis values it through the estimated lifetime salary premium of researchers who trained at CERN compared with similar peers who did not. Supplier spillovers and freely available software form a combined category; its percentage is not split into separate supplier and software shares.
| Benefit channel | Share of estimated incremental benefits | Valuation approach |
| Early-career researcher training | About 40.3% | Estimated lifetime salary premium compared with similar peers who did not train at CERN |
| Industrial suppliers and freely available software | About 37.7% combined | Supplier spillovers draw on supplier accounts, a survey of more than 650 suppliers, and case studies; the software benefit is counted in the same combined category |
| Public-good value | About 10.7% | Estimated from surveys of taxpayers’ willingness to pay |
| Cultural engagement | About 5.7% | Value associated with visits and outreach |
| Scientific publications | About 5.6% | Observable publication uptake and citations |
For suppliers, the analysis estimates about CHF 3 in additional turnover or saved costs for every CHF 1 of high-tech procurement. That is a modeled supplier-level spillover, not money paid to CERN. The 37.7% figure remains the combined share for suppliers and freely available software.
What the simulations say
CERN reports that the model sampled 15 uncertain variables across 50,000 Monte Carlo simulations. In 94% of those runs, the net present value (NPV) was positive. NPV is the value of costs and benefits after future amounts are converted into present-day terms. The 94% is a result within those modeled assumptions, not a guarantee of a positive outcome.
A separate pessimistic cost-overrun scenario produced about an 80% chance of positive NPV. That result belongs to a different scenario and should not be combined with the headline 94% figure. In the analysis’s reported values, the NPV was CHF 3.3 billion when parameters were fixed at their best estimates, while half of the simulation runs exceeded CHF 5.3 billion. Both amounts are in 2016-price Swiss francs.
The model’s time and money assumptions
The analysis covered 1993 through 2038 and expressed values in constant 2016 Swiss francs. It applied a 3% discount rate, the rate cited for public projects in European Commission guidance. In the analysis’s planning snapshot, 2038 was the expected end of operations; a later estimate put that expected end at 2041.
