Large Language Model Prediction Capabilities: Evidence from a Real-World Forecasting Tournament

Abstract: Accurately predicting the future would be an important milestone in the capabilities of artificial intelligence. However, research on the ability of LLMs to provide probabilistic predictions about future events remains nascent. To empirically test this ability, we enrolled OpenAI's state-of-the-art LLM, GPT-4, in a three-month forecasting tournament hosted on the Metaculus platform. The tournament, running from July to October 2023, attracted 843 participants and covered diverse topics including Big Tech, U.S. politics, viral outbreaks, and the Ukraine conflict. Focusing on binary forecasts, we show that GPT-4's probabilistic forecasts are significantly less accurate than the median human-crowd forecasts. We find that GPT-4's forecasts did not significantly differ from the no-information forecasting strategy of assigning a 50% probability to every question. We explore a potential explanation, that GPT-4 might be predisposed to predict probabilities close to the midpoint of the scale, but our data do not support this hypothesis. Overall, we find that GPT-4 significantly underperforms in real-world predictive tasks compared to median human-crowd forecasts. A potential explanation for this underperformance is that in real-world forecasting tournaments, the true answers are genuinely unknown at the time of prediction; unlike in other benchmark tasks like professional exams or time series forecasting, where strong performance may at least partly be due to the answers being memorized from the training data. This makes real-world forecasting tournaments an ideal environment for testing the generalized reasoning and prediction capabilities of artificial intelligence going forward.

• The paper reveals that GPT-4’s forecasts yield Brier scores comparable to a no-information baseline, significantly underperforming human crowd predictions.
• The study highlights that GPT-4 was directionally correct only 69.57% of the time, while humans achieved 95.65% accuracy in diverse binary predictions.
• The analysis suggests that GPT-4’s conservative probability estimates underscore its challenges in generalizing probabilistically to out-of-distribution events.

Evaluating the Predictive Abilities of LLMs Through a Real-World Forecasting Tournament

The paper "LLM Prediction Capabilities: Evidence from a Real-World Forecasting Tournament" presents a rigorous assessment of GPT-4's forecasting capabilities in comparison to a median human crowd. Despite the potential of LLMs in varied domains, the study reveals significant underperformance of GPT-4 in probabilistic predictions when placed in a real-world forecasting context on the Metaculus platform.

Methodology

The research involved enrolling GPT-4 in a forecasting tournament from July to October 2023. This setup provided a natural test environment to evaluate its forecasting prowess on a diverse set of binary questions across topics such as Big Tech, U.S. politics, and global conflicts. The intention was to circumvent issues of training-data memorization by testing the model in an environment where answers were unknown at prediction time.

Key Findings

1. Performance Comparison: GPT-4's predictive accuracy fell short of the median human-crowd forecasts, which were significantly more reliable. A Brier score analysis showed that GPT-4's predictions did not statistically differ from a no-information baseline, underscoring difficulties in surpassing even a 50% probability assignment strategy.
2. Directional Accuracy: GPT-4 was directionally correct in 69.57% of its forecasts, yet this performance was still inferior to the human crowd's 95.65%. This indicates notable challenges in prediction precision.
3. Potential Conservatism: The study explored whether GPT-4 exhibited a tendency towards mid-range probability estimates. Although this hypothesis was tentatively supported by a coefficient of variation analysis, statistical tests did not confirm significant variance differences.

Theoretical and Practical Implications

The findings underscore the current limitations in LLMs' ability to generalize probabilistically to out-of-distribution scenarios. GPT-4's underwhelming performance highlights a crucial gap in its application to domains requiring future event predictions—fields that are economically significant, such as policy-making and strategic planning.

From a theoretical angle, the study reinforces the importance of distinguishing genuine reasoning capabilities from memorization within AI systems. This differentiation is vital for evaluating artificial intelligence's potential across complex, real-world tasks, moving beyond simplistic question-answer settings often used in benchmarks.

Future Directions

Several avenues for future research arise from these results:

• Improving Real-Time Information Access: Addressing the knowledge cutoff within LLMs by embedding mechanisms for real-time information updating without human intervention.
• Harnessing Diverse Model Ensembles: Utilizing multiple LLM instances across varied configurations and datasets may help emulate a wisdom-of-the-crowds effect, potentially improving forecast accuracy.
• Refining Aggregation Techniques: The study suggests potential in Bayesian Model Averaging for combining machine and human forecasts, although such techniques will require enhancement to effectively incorporate LLMs.
• Exploring Hybrid Prediction Models: Investigating systems combining human intuition with LLM outputs may lead to superior forecasting capabilities, fostering synergy between human and machine cognition.

Conclusion

While GPT-4 showcases impressive abilities in various tasks, forecasting remains a domain necessitating further refinement. The current limitation points towards an opportunity for advancing AI systems to competently tackle prediction-based applications. Ultimately, this study provides critical insights to guide both the progression and deployment of LLMs in real-world, economically relevant scenarios.