What logical fallacy does a husband exhibit by assuming a World's Fair will fail due to lack of advertising?

The logical fallacy exhibited by the husband is causal oversimplification. This fallacy occurs when someone oversimplifies the cause of an event by attributing it to a single factor while ignoring other relevant factors that could contribute to the outcome. In this scenario, the husband's assumption that the World's Fair will fail solely due to a lack of advertising fails to consider other potential reasons for success or failure, such as the quality of the exhibits, the interest of the target audience, or external economic conditions. By neglecting these other influences, he simplifies a complex situation into one misleading cause, which exemplifies causal oversimplification.