November 19, 2014
By Aleksander Berentsen, Samuel Huber and Alessandro Marchesiani
We investigate the positive and normative implications of a tax on financial market transactions in a dynamic general equilibrium model, where agents face idiosyncratic liquidity shocks and financial trading is essential. Our main finding is that agents’ portfolio choices display a pecuniary externality which results in too much trading. We calibrate the model to U.S. data and find an optimal tax rate of 2.5 percent. Imposing this tax reduces trading in financial markets by 30 percent.
It is difficult to think why a Tobin tax would make sense in a standard DSGE model. The paper above takes into account that people have two types of assets, liquid and illiquid ones. Naturally, they would like to minimize the amount of liquid assets they carry around as they typically have lower returns. The authors point out that having liquid assets provides, however, a positive externality onto the economy. One way to entice people to hold more of them is to make conversions between liquid and illiquid assets more costly, the Tobin tax. And the welfare benefit seems to be quite substantial.
November 18, 2014
By Kyle Herkenhoff
Unemployed households’ access to unsecured revolving credit (credit cards) nearly quadrupled from about 12 percent to about 45 percent over the last three decades. This paper analyzes how this large increase in revolving credit has impacted the business cycle. The paper develops a general equilibrium business cycle model with search in both the labor market and in the credit market. This generates a very rich and empirically plausible level of heterogeneity in work and credit histories while at the same time permitting a tractable model solution. Calibrating to the observed path of credit use between 1974 and 2012, I find that the large growth in credit access leads to deeper and longer recessions as well as moderately slower recoveries. Relative to an economy with credit fixed at 1970s levels, employment reaches its trough about 1 quarter later and remains depressed by up to .8 percentage points three years after the typical recession in this time period (e.g. employment is depressed by 2.8% rather than 2%). The mechanism is that when borrowing opportunities are easy to find, households optimally search for better-paying but harder-to-find jobs knowing that if the job search fails they can obtain credit to smooth consumption. Despite longer recessions and slower recoveries, increased credit card use enhances welfare by reducing consumption volatility and improving job-match quality.
It was seem at first counterintuitive that higher credit card debt, longer recession and more unemployment are welfare-enhancing, but it looks like matches are so much better in the search process that the outcome turns out to be better. And this despite the high credit card interest rates. This reminds me how entrepreneurship can be a driver for growth despite the high failure rate. As long as there is some mechanism in place that allows to capture at least some of the risk, taking risks is a good strategy.
November 11, 2014
By Lorenzo Menna and Patrizio Tirelli
In the workhorse DSGE model, the optimal steady state inflation rate is near to zero or slightly negative and inflation is almost completely stabilized along the business cycle (Schmitt-Grohé and Uribe, 2011). We reconsider the issue, allowing for agent heterogeneity in the access to the market for interest bearing assets. We show that inflation reduces inequality and that LAMP can justify relatively high optimal inflation rates. When we calibrate the share of constrained agents to fit the wealth Gini index for the US, the optimal inflation rate is well above 2%. The optimal response to shocks is also affected. Rather than using public debt to smooth tax distortions, the Ramsey planner front loads tax rates and reduces public debt variations in order to limit the redistributive effects of debt service payments.
Intriguing paper that, for once, does not rely on downward nominal price rigidities to justify positive inflation. It also implies that a little dose of debt monetization is to some extent justified. This has to get a few people thinking.
November 5, 2014
By Marco Del Negro, Raiden Hasegawa and Frank Schorfheide
We provide a novel methodology for estimating time-varying weights in linear prediction pools, which we call Dynamic Pools, and use it to investigate the relative forecasting performance of DSGE models with and without financial frictions for output growth and inflation from 1992 to 2011. We find strong evidence of time variation in the pool’s weights, reflecting the fact that the DSGE model with financial frictions produces superior forecasts in periods of financial distress but does not perform as well in tranquil periods. The dynamic pool’s weights react in a timely fashion to changes in the environment, leading to real-time forecast improvements relative to other methods of density forecast combination, such as Bayesian Model Averaging, optimal (static) pools, and equal weights. We show how a policymaker dealing with model uncertainty could have used a dynamic pools to perform a counterfactual exercise (responding to the gap in labor market conditions) in the immediate aftermath of the Lehman crisis.
Much work has be done in recent years to estimate DSGE model for forecasting purposes. Despite the fact that they are designed for these purposes, they turn out to be surprisingly useful. This paper continues in this line of research and shows that in fact DSGE models are most useful when other model are most likely to fail: when things are out of the ordinary. In hindsight this makes absolute sense. This is when you get out of the comfort zone of small fluctuations around a trend and theory can help you determine how agent react to event that are out of the sample. It turns out that instead of ditching DSGE models during the last crisis, as many have advocated, we should have used them even more than usual!
October 28, 2014
By Claudio Michelacci and Hernan Ruffo
We argue that US welfare would rise if unemployment insurance were increased for younger and decreased for older workers. This is because the young tend to lack the means to smooth consumption during unemployment and want jobs to accumulate high-return human capital. So unemployment insurance is most valuable to them, while moral hazard is mild. By calibrating a life cycle model with unemployment risk and endogenous search effort, we find that allowing unemployment replacement rates to decline with age yields sizeable welfare gains to US workers.
This paper may seem obvious, but 1) it quantifies that this is economically significant, and 2) did you think about this? Targeting transfers to the population that needs them most is always going to improve things. This paper highlights one such target.
October 25, 2014
By Yasuo Hirose and Atsushi Inoue
This paper examines how and to what extent parameter estimates can be biased in a dynamic stochastic general equilibrium (DSGE) model that omits the zero lower bound (ZLB) constraint on the nominal interest rate. Our Monte Carlo experiments using a standard sticky-price DSGE model show that no significant bias is detected in parameter estimates and that the estimated impulse response functions are quite similar to the true ones. However, as the probability of hitting the ZLB increases, the parameter bias becomes larger and therefore leads to substantial differences between the estimated and true impulse responses. It is also demonstrated that the model missing the ZLB causes biased estimates of structural shocks even with the virtually unbiased parameters.
Beyond the issue that this paper highlights, we should remember that for any estimation that covers the past decade we likely cannot use the standard methods that assume symmetric responses for positive and negative deviations from the mean in the data. I suspect we are going to see a lot of lousy regressions that blindly throw variables into a non-structural estimation and pretend to get reliable results.
October 23, 2014
By Jordi Galí
I analyze the effects of an increase in government purchases financed entirely through seignorage, in both a classical and a New Keynesian framework, and compare them with those resulting from a more conventional debt-financed stimulus. My findings point to the importance of nominal rigidities in shaping those effects. Under a realistic calibration of such rigidities, a money-financed fiscal stimulus is shown to have very strong effects on economic activity, with relatively mild inflationary consequences. If the steady state is sufficiently inefficient, an increase in government purchases may increase welfare even if such spending is wasteful.
On a regular basis, I get emails enquiring how to publish on RePEc some new system that will solve all of the world’s economic problems. Usually, this involves distributing money. This paper is also about distributing money to solve economic problems, but there are two major differences: Jordi Galí is no lunatic, and he only seeks to deal with temporary economic problems as they arise during a business cycle. The key here that nominal rigidities in prices and wages can do their magic and increase aggregate demand. Of course, prices eventually rise and the stimulus dissipates, but the temporary boosts is valuable when it matters most, given a level of rigidity that is plausible. The good old unemployment-inflation trade-off, only with a lag. I wonder though what will happen to the ridigity of prices and wages in a world where money policy becomes active in such ways. Wouldn’t they become more flexible in anticipation of more frequent money stimuli?