A dynamic programming approach to constrained portfolios

This paper studies constrained portfolio problems that may involve constraints on the probability or the expected size of a shortfall of wealth or consumption. Our first contribution is that we solve the problems by dynamic programming, which is in contrast to the existing literature that applies the martingale method. More precisely, we construct the non-separable value function by formalizing the optimal constrained terminal wealth to be a (conjectured) contingent claim on the optimal non-constrained terminal wealth. This is relevant by itself, but also opens up the opportunity to derive new solutions to constrained problems. As a second contribution, we thus derive new results for non-strict constraints on the shortfall of inter¬mediate wealth and/or consumption

Are risk preferences dynamic? : Within-subject variation in risk-taking as a function of background music

This paper investigates whether preference interactions can explain why risk preferences change over time and across contexts. We conduct an experiment in which subjects accept or reject gambles involving real money gains and losses. We introduce within-subject variation by alternating subjectively liked music and disliked music in the background. We find that favourite music increases risk-taking, and disliked music suppresses risk-taking, compared to a baseline of no music. Several theories in psychology propose mechanisms by which mood affects risktaking, but none of them fully explain our results. The results are, however, consistent with preference complementarities that extend to risk preference

Complexity and monetary policy : [Version August 10, 2012]

The complexity resulting from intertwined uncertainties regarding model misspecification and mismeasurement of the state of the economy defines the monetary policy landscape. Using the euro area as laboratory this paper explores the design of robust policy guides aiming to maintain stability in the economy while recognizing this complexity. We document substantial output gap mismeasurement and make use of a new model data base to capture the evolution of model specification. A simple interest rate rule is employed to interpret ECB policy since 1999. An evaluation of alternative policy rules across 11 models of the euro area confirms the fragility of policy analysis optimized for any specific model and shows the merits of model averaging in policy design. Interestingly, a simple difference rule with the same coefficients on inflation and output growth as the one used to interpret ECB policy is quite robust as long as it responds to current outcomes of these variables

Test of the German Resilience

From its early post-war catch-up phase, Germany’s formidable export engine has been its consistent driver of growth. But Germany has almost equally consistently run current account surpluses. Exports have powered the dynamic phases and helped emerge from stagnation. Volatile external demand, in turn, has elevated German GDP growth volatility by advanced countries’ standards, keeping domestic consumption growth at surprisingly low levels. As a consequence, despite the size of its economy and important labor market reforms, Germany’s ability to act as global locomotive has been limited. With increasing competition in its traditional areas of manufacturing, a more domestically-driven growth dynamic, especially in the production and delivery of services, will be good for Germany and for the global economy. Absent such an effort, German growth will remain constrained, and Germany will play only a modest role in spurring growth elsewhere

Fiscal consolidation strategy

In the aftermath of the global financial crisis and great recession, many countries face substantial deficits and growing debts. In the United States, federal government outlays as a ratio to GDP rose substantially from about 19.5 percent before the crisis to over 24 percent after the crisis. In this paper we consider a fiscal consolidation strategy that brings the budget to balance by gradually reducing this spending ratio over time to the level that prevailed prior to the crisis. A crucial issue is the impact of such a consolidation strategy on the economy. We use structural macroeconomic models to estimate this impact focussing primarily on a dynamic stochastic general equilibrium model with price and wage rigidities and adjustment costs. We separate out the impact of reductions in government purchases and transfers, and we allow for a reduction in both distortionary taxes and government debt relative to the baseline of no consolidation. According to the model simulations GDP rises in the short run upon announcement and implementation of this fiscal consolidation strategy and remains higher than the baseline in the long run. We explore the role of the mix of expenditure cuts and tax reductions as well as gradualism in achieving this policy outcome. Finally, we conduct sensitivity studies regarding the type of model used and its parameterization

Reinforcement learning for business modeling.

This chapter summarizes the reinforcement learning theory, emphasizing its relationship with dynamic programming (reinforcement learning algorithms may replace dynamic programming when a full model of the environment is not available) and analysing its limitations as a tool for modelling human and organizational behaviour

The effect of anticipated and experienced regret and pride on investors' future selling decisions : [Version November 2012]

This paper investigates the effect of anticipated/experienced regret and pride on individual investors’ decisions to hold or sell a winning or losing investment, in the form of the disposition effect. As expected the results suggest that in the loss domain, low anticipated regret predicts a greater probability of selling a losing investment. While in the gain domain, high anticipated pride indicates a greater probability of selling a winning investment. The effects of high experienced regret/pride on the selling probability are found as well. An unexpected finding is that regret (pride) seems to be not only relevant for the loss (gain) domain, but also for the gain (loss) domain. In addition, this paper presents evidence of interconnectedness between anticipated and experienced emotions. The authors discuss the implications of these findings and possible avenues for further research

Has Europe been catching up? : An industry level analysis of venture capital success over 1985 – 2009 : [Version November 2012]

After nearly two decades of US leadership during the 1980s and 1990s, are Europe’s venture capital (VC) markets in the 2000s finally catching up regarding the provision of financing and successful exits, or is the performance gap as wide as ever? Are we amid an overall VC performance slump with no encouraging news? We attempt to answer these questions by tracking over 40,000 VC-backed firms stemming from six industries in 13 European countries and the US between 1985 and 2009; determining the type of exit – if any – each particular firm’s investors choose for the venture

Is venture capital a local business? : A test of the proximity and local network hypotheses

Venture capital (VC) investment has long been conceptualized as a local business , in which the VC’s ability to source, syndicate, fund, monitor, and add value to portfolio firms critically depends on their access to knowledge obtained through their ties to the local (i.e., geographically proximate) network. Consistent with the view that local networks matter, existing research confirms that local and geographically distant portfolio firms are sourced, syndicated, funded, and monitored differently. Curiously, emerging research on VC investment practice within the United States finds that distant investments, as measured by “exits” (either initial public offering or merger & acquisition) out-perform local investments. These findings raise important questions about the assumed benefits of local network membership and proximity. To more deeply probe these questions, we contrast the deal structure of cross-border VC investment with domestic VC investment, and contrast the deal structure of cross-border VC investments that include a local partner with those that do not. Evidence from 139,892 rounds of venture capital financing in the period 1980-2009 suggests that cross-border investment practice, in terms of deal sourcing, syndication, and performance indeed change with proximity, but that monitoring practices do not. Further, we find that the inclusion of a local partner in the investment syndicate yields surprisingly few benefits. This evidence, we argue, raises important questions about VC investment practice as well as the ability of firms to capture and lever the presumed benefits of network membership

Dissecting saving dynamics: measuring wealth, precautionary, and credit effects

We argue that the U.S. personal saving rate’s long stability (1960s–1980s), subsequent steady decline (1980s–2007), and recent substantial rise (2008–2011) can be interpreted using a parsimonious ‘buffer stock’ model of consumption in the presence of labor income uncertainty and credit constraints. Saving in the model is affected by the gap between ‘target’ and actual wealth, with the target determined by credit conditions and uncertainty. An estimated structural version of the model suggests that increased credit availability accounts for most of the long-term saving decline, while fluctuations in wealth and uncertainty capture the bulk of the business-cycle variation