In a build-operate-transfer (BOT) road project, the government offers a concession contract to a private investor based on traffic demand information. When the government is privately informed about the demand information—namely, the potential traffic demand (PTD)—it might be challenging for the private investor to quantify the project’s prospects, which could diminish its enthusiasm for involvement. In that case, the government has incentive to design a concession contract that acts as a signal of facility demand to the private investor. This study uses a signaling model to develop an incentive-compatible BOT contract when the government possesses an informational advantage concerning PTD. We find that the optimal contract for the government under the high-PTD condition is distorted relative to a symmetric-information contract. However, this distortion comes at the cost of social welfare loss, which can be viewed as signaling cost, and it is affected by PTD variation and the marginal social cost of public funds. In a separating equilibrium, optimal contracts lie in one of four regions whose bounds are determined by PTD variation. We further extend the research by considering the private investor’s risk-averse attitude. We find that the existence of an optimal signaling mechanism is influenced by the extent of risk aversion (ERA). Interestingly, however, a risk-averse attitude does not magnify the distortion of an asymmetric-information contract, and the signaling cost decreases with ERA. The ranges of separating equilibrium outcomes are also influenced by ERA. Based on our findings, we derive some policy insights regarding BOT contracts design.

中文翻译：

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交通需求信息不对称下的建设-运营-转让道路信号合同设计

在建设-经营-转让 (BOT) 道路项目中，政府根据交通需求信息向私人投资者提供特许合同。当政府私下获悉需求信息（即潜在交通需求（PTD））时，私人投资者可能难以量化项目的前景，这可能会降低其参与的热情。在这种情况下，政府有动力设计特许权合同，作为向私人投资者发出设施需求的信号。本研究使用信号模型在政府拥有有关 PTD 的信息优势时开发激励兼容的 BOT 合约。我们发现，在高 PTD 条件下，政府的最优契约相对于对称信息契约来说是扭曲的。然而，这种扭曲是以社会福利损失为代价的，这可以被视为信号成本，并且受到PTD变化和公共资金边际社会成本的影响。在分离均衡中，最优契约位于四个区域之一，其边界由 PTD 变化确定。我们通过考虑私人投资者的风险规避态度来进一步扩展研究。我们发现最优信号机制的存在受到风险厌恶程度（ERA）的影响。然而有趣的是，规避风险的态度并不会放大不对称信息合约的扭曲，并且信号成本随着 ERA 的增加而降低。分离均衡结果的范围也受到 ERA 的影响。根据我们的研究结果，我们得出了一些有关 BOT 合同设计的政策见解。