6월 2주차

First-price auctions have become common in online display advertising, but they create a practical problem: advertisers pay what they bid while often seeing only whether they won or lost. This opacity can lead to overpayment or missed impressions, especially when market prices change throughout the day. We develop two Bayesian multiarmed bandit methods that help advertisers learn from limited auction feedback and adjust bids dynamically. The methods use auction structure—if one bid wins, higher bids would also have won—to infer market prices more efficiently and adapt to nonstationary bidding environments. Evidence from simulations, offline market logs, online replay, and large-scale A/B tests on a major Chinese advertising platform shows that these methods reduce advertising costs while preserving winning rates. For practitioners, the approach offers an implementable way to automate bid shading, improve return on investment, and decide when paid market price signals are worth acquiring. For platforms and policymakers, the findings highlight how feedback design and price transparency affect advertiser efficiency in first-price auction markets.

As the cybersecurity landscape shifts toward more sophisticated, artificial intelligence–enabled, and unpredictable threats, employees are increasingly targeted as the primary entry points for breaches. Modern incidents, such as zero-day exploits and ransomware, often present employees with situations that are technically complex and ambiguous. We show that these situations are often perplexing for employees. Security perplexity is a tense cognitive state experienced by employees in threatening cybersecurity situations, arising from a conflict between perceived pressure to act and a simultaneous state of confusion and uncertainty about how to do so. Through rigorous construct development and multistage testing, we demonstrate that perplexity disrupts how employees cope with threats. Left unmanaged, this tension reaches a tipping point where employees move from proactive protection to maladaptive behaviors like avoidance or emotion coping. Cybersecurity managers must shift their focus from simple threat detection toward action-clarity to better support their teams. Organizations should prioritize employee coping by providing procedural walkthroughs to build confidence. Implementing a "pause-and-assess" principle with decision checklists helps employees manage ambiguity, reduces emotional escalation, and ensures a more resilient organizational response.