Why did the HST cost more than expected?

The HST (Harmonized Sales Tax) cost more than expected due to several factors, including underestimations of the administrative complexities involved in merging provincial and federal sales tax systems. Additionally, there were challenges related to compliance and public resistance, which resulted in increased administrative costs. Economic conditions, such as fluctuations in consumer spending and business investment, also contributed to revenue shortfalls, leading to higher-than-anticipated costs. Lastly, the initial projections failed to adequately account for the potential impact on various sectors, which further exacerbated financial discrepancies.