現存探討金融發展與經濟成長之互動關係的文獻，都只關注地上（或官方）經濟層面上的表現，完全忽略了地下經濟在兩者互動關係中所扮演的角色。為彌補文獻，本文首先進行臺灣地下經濟規模的估算，然後以共整合模型探討地下經濟對我國金融發展（包含銀行及股市）與官方經濟成長的因果關係、相互解釋的能力、模型配適度與預測能力是否有所影響。結果顯示，在長期均衡關係中，地下經濟的存在使我國金融體系原是符合銀行導向為基礎的結論消失了。在長期因果關係中，不論是否考慮地下經濟，我國均存在需求追隨的股市發展型態，但考慮地下經濟之後需求追隨的銀行發展型態不復存在。在短期互動關係中，考量地下經濟之前，官方經濟成長促進銀行發展但不影響股市發展，而銀行與股市之間不存在資金排擠效應；考量地下經濟之後，官方經濟成長降低股市發展但不影響銀行發展，銀行與股市之間出現資金排擠的效應。在短期因果關係中，地下經濟的存在會顯著影響金融發展與官方經濟成長之間的因果關係。預測誤差變異數分解則發現，地下經濟為我國官方經濟成長及股市發展的重要解釋變數。最後，在樣本內配適度及樣本外預測能力評比中發現，將地下經濟納入的模型表現較佳。

Most recent studies exploring the empirical correlation between financial development and economic growth (the finance-growth nexus) only focus on the growth rate of the formal (or official) economy, while completely ignorting the roles of the shadow economy. To explore the roles played the shadow economy in this correlation, we first estimate the size of said economy in Taiwan and then employ the cointegration model to investigate whether or not the presence of this type of economy significantly alters the correlation between financial development (including banking and stock markets) and economic growth in Taiwan. We proceed with our investigations by comparing two models. The first one examines the correlation between financial development and economic growth, without considering the shadow economy. We then compare this to the second one, which explores the correlations among financial development, the official economy, and the shadow economy. We find that whether the shadow economy is present or not plays an important role in determining the finance-growth nexus of Taiwan. Furthermore, we present some results showing that the second one outperforms the first one in terms of the in-sample fit and the out-of-sample forecasts, validating that the shadow economy does play an important role in the finance-growth nexus of Taiwan.