我们为什么需要绿色金融?——从全球经验事实到基于经济增长框架的理论解释

当前,绿色金融备受关注,然而该领域的基础理论尚需进一步强化。根据经济学的一般原理,由于污染的外部性问题,环保的主要力量应当是公共部门而非金融系统。然而为何越来越多国家选择发展绿色金融?其背后的经济学原理是什么?深入探讨这些问题是有效制定政策、构建绿色金融理论体系的基础。本文基于跨国面板数据的分析表明,绿色金融对经济增长具有显著的促进效应,表现出与公共部门环保投入的显著差异。在此基础上,本文构建基于经济增长框架的绿色金融理论模型,对经验事实给出理论解释。模型证明:绿色金融的成本分摊与风险分担功能使其具有独特的长期增长效应,是经济发展必然选择;绿色金融政策与绿色财政政策的协调配合是实现高质量发展的有效手段。本文从理论层面回答了“为什么需要绿色金融”这一问题,为绿色金融的经济学理论发展和政策分析提供了可借鉴的框架。

Operating Risks and Firm Leverage

The literature on corporate finance has traditionally categorized studies on firm leverage under capital structure. However, macroeconomists have begun to study the topic of firm leverage since the 2008 global financial crisis. Macroeconomic studies have argued that changes in leverage are related to a contraction or expansion of credit, i.e. the credit cycle, or an additional business cycle overall. Another category of studies have argued that the differences in leverage are tied to structural differences in firm characteristics, including ownership, firm size, and financing constraints. The two types of studies have advanced our understanding of macroeconomic fluctuations, although they have left some gaps in the literature. The first type has argued that changes in credit cycle and firm leverage are causes of economic fluctuations. However, the question remains, what leads to the cyclical fluctuations in leverage？ The second type, in contrast, has failed to explain the observed fluctuations. For instance, they have shown that ownership affects firm leverage, but they have failed to explain the structural and cyclical changes in firm leverage. The motivation of this paper is to examine the fundamental mechanism behind the cyclical changes in firm leverage. This paper focuses on one dominant determinant for the firm's investment, the firm's expectation for the future. The firm's decision to borrow to finance an investment is a risky intertemporal decision. The increase in leverage can significantly raise the return on assets during a boom period, but the decision can lead to great loss in an economic recession. Following this argument, an enterprise's choice of leverage ratio should be pro-cyclical if the expectation of a representative agent in the economy is optimistic in times of economic prosperity (i.e. increasing risk preference) and pessimistic (i.e. decreasing risk preference) in times of economic recession. In this paper, we concentrate on the firm's most direct operating risks, measured by the standard deviation of ROA within the “year*city*2-digit industry” cell. This study uses data from the Industrial Enterprise Database (1998-2013). We find that the firm's operating decisions become more conservative as the firm's operating risks increase, as demonstrated by a decline in leverage. We decompose leverage as a “liability-asset” to show that assets and liabilities both drop in times of rising operating risks. The decrease in liability is larger than that in assets, which leads to a downward slope in leverage. Moreover, we show that the key mechanism is the contraction in investment, suggesting that the process of de-leveraging is equivalent to a decrease in investment. After separating liabilities by long-and short-(current) term liabilities, we find that the decrease in current liabilities is prioritized when firms are dealing with increasing risks. Grouped by ownership, non-state-owned enterprises (non-SOE) are most sensitive to the changes in operating risks, while SOEs are much more stable. These findings may be explained by the differences in their financing capacity, industry characteristics, and operating objectives. This paper makes the following contributions. First, it advances the literature on firm leverage cycles. Studies on credit cycles have focused on the role of financial intermediates as credit suppliers. This paper, in contrast, focuses on the role of credit demand to show the pro-cyclical pattern that exacerbates economic fluctuations. Second, we examine the changes in liabilities based on duration, ownership, and possible mechanism. Third, the firm's decision is used as a framework to examine the leverage cycle, which results in policy implications. Specifically, credit cycle theorists have argued that credit should be eased in an economic recession. However, this study shows that while credit easing may alleviate the liquidity risks in the financial market, it fails to stimulate the real economy if the firms have a negative outlook for the future. It also indicates that monetary easing prior to a recovery in the firm's expectation will divert finances out of the real economy. Furthermore, credit easing does not stabilize the real economy if the high-yielding firms are more conservative. Rather, it may aggravate the problem of adverse selection and financial risks. This paper suggests that a more effective method would be to apply expansionary fiscal policies to stabilize the firms' demand and strengthen their confidence, then apply credit easing as a complementary tool.