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on Computational Economics |
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Issue of 2017‒08‒20
seven papers chosen by |
| By: | Visser, T.R.; Spliet, R. |
| Abstract: | In this paper we introduce several new methods for eciently evaluating moves in neighborhood search heuristics for routing problems with time-dependent travel times. We consider both the case that route duration is constrained and the case that route duration appears in the objective. We observe that the composition of piecewise linear functions can be evaluated in various orders when computing the route duration. We use this to develop a new tree based data structure to improve the complexity of computations and memory usage. This also allows us to present methods that have the best known computational complexity, while they do not even require a lexicographic order of search. Our numerical experiments illustrate the trade-o between computation time and memory usage among the dierent methods. On 1000 customer instances, our methods are able to speed-up a construction heuristic by up to 8.89 times and an exchange neighborhood improvement heuristic by up to 3.94 times, without requiring excessive amounts of memory. |
| Keywords: | Vehicle Routing Problems, Neighborhood Search, Feasibility Check, Time-dependent Travel, Times, First-in-first-out, Duration constraints |
| Date: | 2017–08–03 |
| URL: | http://d.repec.org/n?u=RePEc:ems:eureir:100852&r=cmp |
| By: | Dollevoet, T.A.B.; van Essen, J.T.; Glorie, K.M. |
| Abstract: | In order to perform medical surgeries, hospitals keep large inventories of surgical in- struments. These instruments need to be sterilized before each surgery. Typically the instruments are kept in trays. Multiple trays may be required for a single surgery, while a single tray may contain instruments that are required for multiple surgical procedures. The tray optimization problem (TOP) consists of three main decisions: (i) the assignment of instruments to trays, (ii) the assignment of trays to surgeries, and (iii) the number of trays to keep in inventory. The TOP decisions have to be made such that total operating costs are minimized and such that for every surgery sufficient instruments are available. This paper presents and evaluates several exact and heuristic solution methods for the TOP. We compare solution methods on computation time and solution quality. Moreover, we conduct simulations to evaluate the performance of the solutions in the long run. The novel methods that are provided are the first methods that are capable of solving instances of realistic size. The most promising method consists of a highly scalable advanced greedy algorithm. Our results indicate that the outcomes of this method are, on average, very close to the outcomes of the other methods investigated, while it may be easily applied by (large) hospitals. The findings are robust with respect to fluctuations in long term OR schedules. |
| Keywords: | OR in Health Services, Sterile Inventory, Integer Linear Programming, Row and Column Generation, Heuristics |
| Date: | 2017–08–07 |
| URL: | http://d.repec.org/n?u=RePEc:ems:eureir:100837&r=cmp |
| By: | Jair N. Ojeda-Joya (Banco de la República de Colombia); Oscar E. Guzman (Contraloría de la República) |
| Abstract: | In this paper we estimate the effect of government consumption shocks on GDP using a panel of 21 developing economies. Our goal is to better understand the reasons for the low fiscal multipliers found in the literature by performing estimations for alternative exchange rate regimes, business-cycle phases, and monetary policy stances. In addition, we perform counterfactual simulations to analyze the possible gains from fiscal-monetary policy coordination. The results imply that government consumption shocks are usually followed by monetary policy tightening in developing economies with flexible regimes. Our simulations show that this reaction partially explains the presence of low fiscal multipliers in these economies. Government consumption shocks imply lower multipliers in developing economies during flexible regimes, economic slowdowns or monetary contractions. In addition, implementing fiscal programs during monetary expansions seems to improve significantly their economic stimulus. Classification JEL: E62, E63, F32 |
| Keywords: | Fiscal Policy, Monetary Policy, Structural Vector Autoregression, Exchange Rate Regime, Panel VAR |
| Date: | 2017–08 |
| URL: | http://d.repec.org/n?u=RePEc:bdr:borrec:1010&r=cmp |
| By: | Ingrid Kubin (Department of Economics, Vienna University of Economics and Business); Thomas O. Zörner (Department of Economics, Vienna University of Economics and Business) |
| Abstract: | We augment a model of endogenous credit cycles by Matsuyama et al.(2016) with human capital to study the impact of human capital on the stability of central economic aggregates. Thus we offer a linkage between human capital formation and credit market instability on a macrolevel combined with an analysis of functional income distribution. Human capital is modelled as pure external effect of production following a learning-by-producing approach. Agents have access to two different investment projects, which differ substantially in their next generations spillover effects. Some generate pecuniary externalities and technological spillovers through human capital formation whereas others fail to do so and are subject to financial frictions. Due to this endogenous credit cycles occur and a pattern of boom and bust cycles can be observed. We explore the impact of human capital on the stability of the system by numerical simulations which indicate that human capital has an ambiguous effect on the evolution of the output. Depending on the strength of the financial friction and the output share of human capital it either amplifies or mitigates output fluctuations. This analysis shows that human capital is an essential factor for economic stability and sustainable growth as a high human capital share tends to make the system's stability robust against shocks. |
| Keywords: | Human capital, Learning-by-producing, Credit cycles, Financial instability |
| JEL: | C61 E32 E24 J24 |
| Date: | 2017–08 |
| URL: | http://d.repec.org/n?u=RePEc:wiw:wiwwuw:wuwp251&r=cmp |
| By: | Mark Carlson; Molly Shatto; Missaka Warusawitharana |
| Abstract: | In this note, we describe an algorithm, developed in Carlson, Shan, and Warusawitharana (2013), to match banks that are geographically close and are similar in size and business model. Concurrently, we also release a data set of matched banks obtained from applying this algorithm from 1998 to 2014, as well as some of the associated computer programs. |
| Date: | 2017–08–08 |
| URL: | http://d.repec.org/n?u=RePEc:fip:fedgfn:2017-08-08&r=cmp |
| By: | Antoine Jacquier; Louis Jeannerod |
| Abstract: | We provide an explicit formula giving the optimal number of paths needed to simulate two correlated Brownian motions. |
| Date: | 2017–08 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:1708.05352&r=cmp |
| By: | Seth G Benzell; Laurence J Kotlikoff; Guillermo LaGarda |
| Abstract: | The U.S., according to some measures, has one of the highest marginal effective corporate tax rates (METRs) of any developed country. Yet the tax collects less than 2 percent of GDP. This paper studies the impact of replacing the U.S. corporate tax with a Business Cash Flow Tax (BCFT). Our paper studies BCFT reform with reference to a particular, but reasonably generic, proposal, namely the House Republican “Better Way” tax plan. We use the Global Gaidar Model – a 17-region, global, overlapping-generations model, calibrated to U.N. demographic and IMF fiscal data – to simulate the dynamic, general equilibrium impact of this reform. In the short run, the U.S. capital stock, pre-tax wage rates, and GDP rise by roughly 25 percent, 8 percent, and 9 percent, respectively. Over time, the capital stock and wage rates remain significantly above their baseline values. There is a smaller long-run increase in GDP as workers spend some of their higher wages on additional leisure. The tax reform produces enough additional revenues to permit a reduction in personal income tax rates while maintaining the economy's initial debt-to-GDP ratio. The beneficiaries of the House plan are today's and tomorrow's workers. We also simulate a matching METR cut by the rest of the world, which raises the world interest rate. The short-run increases in the capital stock, pre-tax wage rates, and GDP are smaller. However, along the transition path, all U.S. agents experience slightly higher welfare than under the House plan. This reflects the combination of a higher post-corporate tax world interest rate and Americans' disproportionately large holdings of global assets |
| JEL: | E02 F43 H2 H6 |
| Date: | 2017–08 |
| URL: | http://d.repec.org/n?u=RePEc:nbr:nberwo:23675&r=cmp |