Sharing Some Thoughts on Weitzman's The Share Economy

This paper explores the positive and normative aspects of share contracts. In particular, the paper explores the properties of a share system as advanced by Martin Weitzman in The Share Economy.The model employed highlights a "macroeconomic externality" created in a multi-sector economy with imperfect competition. The introduction of share contracts is shown to influence the comparative static properties of the model economy and in some cases to lead to Pareto superior outcomes.

Financial Intermediation and The Great Depression: A Multiple Equilibrium Interpretation

This paper explores the behavior of the U.S. economy during the interwar period from the perspective of a model in which the existence of non-convexities in the intermediation process gives rise to a multiplicity of equilibria. The resulting indeterminancy is resolved through a sunspot process which leads to endogenous fluctuations in aggregate economic activity. From this perspective, the Depression period is represented as a regime shift associated with a financial crisis. Our model economy has properties which are broadly consistent with observations over the interwar period. Contrary to observation, the model predicts a negative correlation of consumption and investment as well as a highly volatile capital stock. Our model of financial crisis reproduces many aspects of the Great Depression though the model predicts a much sharper fall in investment than is observed in the data. Modifications to our model (adding durable goods and a capacity utilization choice) do not overcome these deficiencies.

The Dynamics of Car Sales: A Discrete Choice Approach

Mankiw [1982] explores the Permanent Income Hypothesis implication that durable expenditures follow an ARMA(1,1) representation. He finds that durable expenditures are represented by an AR(1) process which implies that the rate of depreciation of durables, under the PIH model, is 100%. This finding presents a puzzle. Our paper builds on earlier work which attempts to explain this puzzle by considering the aggregation of the discrete dynamic choices of heterogeneous households. We implement this approach by estimating a dynamic discrete choice model of car replacement. We find that through aggregation we can explain both the AR and MA components of Mankiw's results. Further we find that our model is able to match a VAR representation of car sales, prices and income. We find that most of the variation in car sales is due to shocks which influence the replacement probability.

Exhuming Q: market power capital market imperfections

Evidence of the statistical significance of profits in Q regressions remains one of the principal findings in the empirical investment literature. This result is frequently taken to support the view that capital market imperfections are an important element for understanding investment. This paper challenges that conclusion. We argue that allowing the profit function at the firm level to be strictly concave, reflecting, for example, market power, is sufficient to replicate the Q theory based regression results in which profits are a significant factor determining investment. To be clear, our ability to replicate the existing results does not require the specification of any capital market imperfections. Thus the friction that explains the statistical significance of profits could be market power by sellers rather than capital market imperfections.Capital investments ; Corporate profits ; Regression analysis

Dynamic Behavior of Imperfectly Competitive Economies with Multiple Equilibria

This paper investigates the dynamic behavior of an economy with multiple Nash equilibria. The first part of the paper analyzes an abstract game exhibiting multiple equilibria. A history dependent selection criterion is proposed which induces correlated behavior in equilibrium even though agents are playing one-shot games and disturbances are not correlated over time. The second part of the paper investigates a specific model of multiple equilibria. Here the multiplicity is induced by the presence of a discrete decision on the part of firms regarding their choice of technique. The implications of the selection criterion introduced in the first part of the paper are illustrated through this example. Again correlated behavior emerges in a sequence of independent one-shot games. The model economy may also experience prolonged periods in which a low productivity technology is in use and then, as a consequence of a large real disturbance, may switch to an alternative equilibrium in which a high productivity technology is utilized. The paper also discusses the Pareto ordering of these equilibria.

Mind the (approximation) gap: a robustness analysis

This note continues the discussion of the results reported by Ricardo Caballero and Eduardo Engel (1993), hereafter CE, and Ricardo Caballero, Eduardo Engel, and John Haltiwanger (1997), hereafter CEH, by responding to the results reported in Christian Bayer (2008). Russell Cooper and Jonathan Willis (2004), hereafter CW, find that the aggregate nonlinearities reported in CE and CEH may be the consequence of mismeasurement of the employment gap rather than nonlinearities in plant-level adjustment. Bayer reassesses this finding in the context of the CE model in the case where static employment gaps are observed and concludes that the CW result is not robust to alternative shock processes. We concur with Bayer's assessment that the nonlinearity finding is sensitive to the aggregate profitability shock process. We argue, however, that Bayer's finding does not imply that the mismeasurement problem goes away. Instead, the nonlinearity created by mismeasurement is directly related to the level of the aggregate shock. Once the empirical specification properly incorporates the aggregate shock, the nonlinearity test is robust to alternative shock processes and confirms the results in CW. More importantly, we demonstrate that the CW findings are robust to alternative shock processes for the natural case of unobserved gaps as examined by CE and CEH.

Inventories and the Propagation of Sectoral Shocks

This paper studies the dynamic properties of an imperfectly competitive economy with inventory holdings. In particular, we focus on the serial correlation in aggregate output and employment produced by the holding of inventories in one sector of the economy and the co-movement between sectors of an economy over the cycle resulting from demand linkages. This model is then contrasted with a simple, competitive real business cycle model with inventories. We find that the predictions of these models with regards to the co-movement of employment may differ. Based on this, we present empirical evidence on the co-movement of employment over the business cycle which is consistent with the predictions of the model of imperfect competition with inventory holdings and demand linkages.

Dollarization and the conquest of hyperinflation in divided societies

This study argues that the delegation of monetary policy control by one country to another can reduce inflation in the delegating country. Hyperinflation is common in a divided society, one in which special interest groups can pressure a weak central government to issue money to finance their own demands while neglecting the country’s overall welfare. A commitment device like dollarization or a currency board, which gives control of the divided country’s money supply to another country, can eliminate this inflation bias. This is illustrated by Argentina’s experience with inflation and a currency board which, in effect, gave control of Argentina’s money supply to the United States. This argument is made precise using a two-country overlapping generations model to study the effects of delegation. The study also finds that a dollarization treaty between the two countries can be welfare-improving for bothDollarization

The Cost of Labor Adjustment: Inferences from the Gap

We study labor adjustment costs. We specify a dynamic optimization problem at the plant-level, allowing for both convex and non-convex adjustment costs. We estimate the parameters of the adjustment process using an indirect inference procedure in which simulated moments are matched with data moments. For this study we use estimates of reduced-form adjustment functions obtained by the gap methodology' reported in Caballero-Engel as data moments. Contrary to evidence at the micro level in support of non-convex adjustment costs, our findings indicate that piecewise quadratic adjustment costs are sufficient to match these aggregate moments.

The economics of labor adjustment: mind the gap

We study inferences about the dynamics of labor adjustment obtained by the "gap methodology" of Caballero and Engel [1993] and Caballero, Engel and Haltiwanger [1997]. In that approach, the policy function for employment growth is assumed to depend on an unobservable gap between the target and current levels of employment. Using time series observations, these studies reject the partial adjustment model and find that aggregate employment dynamics depend on the cross-sectional distribution of employment gaps. Thus, nonlinear adjustment at the plant level appears to have aggregate implications. We argue that this conclusion is not justified: these findings of nonlinearities in time series data may reflect mismeasurement of the gaps rather than the aggregation of plant-level nonlinearities.Labor supply ; Econometric models