اثر توسعه مالی در کوتاه مدت و بلند مدت: نظریه و شواهد از هند

Although many view financial access as a means of reducing poverty or increasing growth, empirical studies have produced contradictory results. One problem is that most studies cover only a short time frame and do not consider dynamic effects. I show that introducing credit in a general model of intertemporal consumption creates a boom in consumption and reduces poverty initially, but eventually reduces mean consumption because credit substitutes for precautionary wealth. Using new consistent consumption data that cover a much longer time period than most studies, my empirical findings show that increased access to bank branches in rural India increased consumption initially and reduced poverty, but consumption later fell and poverty rose. The long-term effect is still positive, however, suggesting that credit may have a beneficial role beyond consumption smoothing.

There are two views of financial development. One holds that financial development is a crucial contributor to growth. This view drove India's efforts to extend bank branches to rural areas in the 1970s and 1980s, the more recent expansion of microcredit to hundreds of millions of households across the world, and the 2006 Nobel Peace Prize to Muhammad Yunus and the Grameen Bank for their work extending financial services to the poor. Yet where credit has long been available a darker and more pessimistic view of the consequences of better financial access also exists. Concerns about over-indebtedness, debt spirals, and farmer suicide mark this view, leading to the worry that credit reinforces poverty rather than alleviating it. The empirical evidence for whether access to financial services helps the poor is contradictory, despite a strong correlation between financial development and growth across countries.1 While Burgess and Pande (2005) find that the large expansion of branch banks into rural India in the 1970s and 1980s significantly reduced poverty, Kochar (2005) and Panagariya (2008) disagree. Microcredit has been the subject of a similar debate, with some studies finding benefits for the poor (Khandker, 2005 and Pitt and Khandker, 1998), others questioning the evidence (Morduch, 1998 and Roodman and Morduch, 2009), and recent experimental and quasi-experimental studies finding only very weak effects of microcredit and low take-up initially.2 Yet the conflicting evidence has not stopped practitioners from making strong claims about the positive impact of microfinance.

Credit is inherently intertemporal, and this paper makes it clear that it is necessary to study its effects in an intertemporal context. Not doing so leads to an incomplete and biased view of the effects of credit. In particular, although the long-term effect of better access to credit may be a decrease in mean consumption, consumers will tend to consume substantially more initially, and so any estimate about the effects of gaining access to credit will depend on when these changes are measured. Approaches that do not deal with the dynamics will tend to produce unstable estimates that are easy to misinterpret and so should be treated with a great deal of caution. One advantage of a complete model is that it helps gives structure to the empirics, tightly specifying what matters, what does not, and what we should be trying to identify. For example, even if banks or microfinance institutions go into high income areas, fixed effects can separate out the effects of income differences, so the endogenous choices of banks do not necessarily affect identification. Similarly, it is straightforward to deal with different growth rates of income, as long as there is enough data to take out the trend. In trying to understand the effects of financial access, it is not necessarily better instruments that matter, but the hard work of collecting more data over a long time.