matching function

Smarandache (1995) defined the notion of neutrosophic sets, which is a generalization of Zadeh's fuzzy set and Atanassov's intuitionistic fuzzy set. In this paper, we first develop some similarity measures of neutrosophic sets. We will present a method to calculate the distance between neutrosophic sets (NS) on the basis of the Hausdorff distance. Then we will use this distance to generate a new similarity measure to calculate the degree of similarity between NS. Finally we will prove some properties of the proposed similarity measures.

The Institute for Labour Market Policy Evaluation (IFAU) is a research insti tute under the Swedish Ministry of Employment, situated in Uppsala. IFAU's objective is to promote, support and carry out: evaluations of the effects of la bour market policies, studies of the functioning of the labour market and evaluations of the labour market effects of measures within the educational sys tem. Besides research, IFAU also works on: spreading knowledge about the ac tivities of the institute through publications, seminars, courses, workshops and conferences; influencing the collection of data and making data easily available to researchers all over the country. IFAU also provides funding for research projects within its areas of interest. The deadline for applications is October 1 each year. Since the researchers at IFAU are mainly economists, researchers from other disciplines are encouraged to apply for funding. IFAU is run by a Director-General. The authority has a board, consisting of a chairman, the Director-General and seven other members. The tasks of the board are, among other things, to make decisions about external grants and give its views on the activities at IFAU. A reference group including representatives for employers and employees as well as the ministries and authorities con cerned is also connected to the institute.

The Institute for Labour Market Policy Evaluation (IFAU) is a research insti tute under the Swedish Ministry of Employment, situated in Uppsala. IFAU's objective is to promote, support and carry out: evaluations of the effects of la bour market policies, studies of the functioning of the labour market and evaluations of the labour market effects of measures within the educational sys tem. Besides research, IFAU also works on: spreading knowledge about the ac tivities of the institute through publications, seminars, courses, workshops and conferences; influencing the collection of data and making data easily available to researchers all over the country. IFAU also provides funding for research projects within its areas of interest. The deadline for applications is October 1 each year. Since the researchers at IFAU are mainly economists, researchers from other disciplines are encouraged to apply for funding. IFAU is run by a Director-General. The authority has a board, consisting of a chairman, the Director-General and seven other members. The tasks of the board are, among other things, to make decisions about external grants and give its views on the activities at IFAU. A reference group including representatives for employers and employees as well as the ministries and authorities con cerned is also connected to the institute.

When the trading process is characterized by search frictions, traders may be rationed so markets need not clear. We build a general equilibrium model with transferable utility where the uncertainty arising from rationing is incorporated in the definition of a commodity, in the spirit of the Arrow-Debreu theory. Prices of commodities then depend not only on their physical characteristics, but also on the probability that their trade is rationed. The standard definition of competitive equilibrium is extended by replacing market clearing with a matching condition which describes a trading technology that is not frictionless. This condition relates the rationing probabilities of buyers and sellers to ratio of buyers to sellers in the market via an exogenous matching function with constant returns, as in standard search-theoretic models. When search frictions vanish, our model is equivalent to the competitive assignment model of . We adopt their approach, which uses linear programming techniques and duality theory, to derive the welfare and existence theorems in our search environment. Our competitive equilibrium notion is equivalent to that of directed (or competitive) search. The strength of our formulation and the linear programming approach is that they allow us to generalize the constrained efficiency and existence results in the directed search literature to a much broader class of economies. Our framework also opens the door to the use of linear programming algorithms for computing equilibria.

When the trading process is characterized by search frictions, traders may be rationed so markets need not clear. We argue that rationing can be part of general equilibrium, even if it is outside its normal interpretation. We build a general equilibrium model where the uncertainty arising from rationing is incorporated in the definition of a commodity, in the spirit of the Arrow-Debreu theory. Prices of commodities then depend not only on their physical characteristics, but also on the probability that their trade is rationed. The standard definition of a competitive equilibrium is extended by replacing market clearing with a matching condition. This condition relates the traders' rationing probabilities to the measures of buyers and sellers in the market via an exogenous matching function, as in the search models of , and . When search frictions vanish (so matching is frictionless) our model is equivalent to the competitive assignment model of Gretsky, Zame (1992, 1999). We adopt their linear programming approach to derive the welfare and existence theorems in our environment.

Monthly panel (1998)(1999)(2000)(2001)(2002)(2003)) data from regional labor offices in Latvia are used to analyze the matching process in a high unemploymentlow labor demand environment and to evaluate the impact of active labor market policy programs on outflows from unemployment. Results suggest that the hiring process is driven by a stock-flow rather than by a traditional matching function: the stock of unemployed at the beginning of the month and flow of vacancies arriving during the month are the key determinants of outflows from unemployment to employment, while stock of vacancies and inflow of unemployed do not play any significant role. We find positive and significant effect of training programs on outflows from unemployment to employment, thus providing strong evidence against recent cuts in training expenditures.

RGD-coupled silk protein-biomaterial lamellar systems were prepared and studied with human cornea fibroblasts (hCFs) to match functional requirements. A strategy for corneal tissue engineering was pursued to replicate the structural hierarchy of human corneal stroma within thin stacks of lamellae-like tissues, in this case constructed from scaffolds constructed with RGD-coupled, patterned, porous, mechanically robust and transparent silk films. The influence of RGD-coupling on the orientation, proliferation, ECM organization, and gene expression of hCFs was assessed. RGD surface modification enhanced cell attachment, proliferation, alignment and expression of both collagens (type I and V) and proteoglycans (decorin and biglycan). Confocal and histological images of the lamellar systems revealed that the bio-functionalized silk human cornea 3D constructs exhibited integrated corneal stroma tissue with helicoidal multi-lamellar alignment of collagen-rich and proteoglycan-rich extracellular matrix, with transparency of the construct. This biomimetic approach to replicate corneal stromal tissue structural hierarchy and architecture demonstrates a useful strategy for engineering human cornea. Further, this approach can be exploited for other tissue systems due to the pervasive nature of such helicoids in most human tissues.

We study different trading processes in the context of a search-based model of endogenous money. We incorporate heterogeneity into the model by allowing multiple meetings of agents and divisible production. We then determine the equilibrium using three different trading mechanisms: auctions, pairwise bargaining and price posting. The welfare under these mechanisms is compared using specific functional forms for utility and cost functions. The analysis is done numerically with the bench mark of a social welfare maximising planner.

We examined contrast sensitivity and suprathreshold apparent contrast with natural images. The spatialfrequency components within single octaves of the images were removed (notch filtered), their phases were randomized, or the polarity of the images was inverted. Of Michelson contrast, root-mean-square (RMS) contrast, and band-limited contrast, RMS contrast was the best index of detectability. Negative images had lower apparent contrast than their positives. Contrast detection thresholds showed spatial-frequency-dependent elevation following both notch filtering and phase randomization. The peak of the spatial-frequency tuning function was approximately 0.5-2 cycles per degree (c/deg). Suprathreshold contrast matching functions also showed spatial-frequency-dependent contrast loss for both notch-filtered and phase-randomized images. The peak of the spatial-frequency tuning function was approximately 1-3 c/deg. There was no detectable difference between the effects of phase randomization and notch filtering on contrast sensitivity. We argue that these observations are consistent with changes in the activity within spatial-frequency channels caused by the higher-order phase structure of natural images that is responsible for the presence of edges and specularities.

Matching dependencies were recently introduced as declarative rules for data cleaning and entity resolution. Enforcing a matching dependency on a database instance identifies the values of some attributes for two tuples, provided that the values of some other attributes are sufficiently similar. Assuming the existence of matching functions for making two attributes values equal, we formally introduce the process of cleaning an instance using matching dependencies, as a chase-like procedure. We show that matching functions naturally introduce a lattice structure on attribute domains, and a partial order of semantic domination between instances. Using the latter, we define the semantics of clean query answering in terms of certain/possible answers as the greatest lower bound/least upper bound of all possible answers obtained from the clean instances. We show that clean query answering is intractable in some cases. Then we study queries that behave monotonically wrt semantic domination order, and show that we can provide an under/over approximation for clean answers to monotone queries. Moreover, non-monotone positive queries can be relaxed into monotone queries.

In this study, we investigate information retrieval (IR) on Turkish texts using a large-scale test collection that contains 408,305 documents and 72 ad hoc queries. We examine the effects of several stemming options and query-document matching functions on retrieval performance. We show that a simple word truncation approach, a word truncation approach that uses language-dependent corpus statistics, and an elaborate lemmatizer-based stemmer provide similar retrieval effectiveness in Turkish IR. We investigate the effects of a range of search conditions on the retrieval performance; these include scalability issues, query and document length effects, and the use of stopword list in indexing.

This paper provides a dynamic analysis of the market for academic publications. Given imperfect information about journals' editorial line, authors can sometimes target a wrong journal; in turn, the editor will desk-reject their paper. An equilibrium is de…ned as a situation where both editors and authors implement their optimal publication strategies, given the matching technology and the prevailing surplus sharing rule. The model can be solved for the equilibrium submission fee, desk rejection rate and ratio between the number of editors and the number of authors.

Subject to a huge and growing number of journal titles in business and economics, scholars sometimes target the wrong journal. Editors resort more and more to paper pre-screening, and desk reject those that do not fit well to the editorial line. This paper provides a dynamic analysis of the market for academic publications that brings into the picture these matching frictions. The key modelling device is a paperjournal matching function, similar to the matching function traditional in labor economics. Our main endogenous variables are the submission fee and the tension in the publication market, itself directly related to the number of journal titles.

We present the results of the first large-scale Turkish information retrieval experiments performed on a TREC-like test collection. The test bed, which has been created for this study, contains 95.5 million words, 408,305 documents, 72 ad hoc queries and has a size of about 800MB. All documents come from the Turkish newspaper Milliyet. We implement and apply simple to sophisticated stemmers and various query-document matching functions and show that truncating words at a prefix length of 5 creates an effective retrieval environment in Turkish. However, a lemmatizer-based stemmer provides significantly better effectiveness over a variety of matching functions.

We survey the microfoundations, empirical evidence and estimation issues underlying the aggregate matching function. Several microeconomic matching mechanisms have been suggested in the literature with some successes but none is generally accepted as superior to all others. Instead, an aggregate matching function with hires as a function of vacancies and unemployment has been successfully estimated for several countries. The Cobb-Douglas restrictions with constant returns to scale perform well. Recent work has utilized disaggregated data to go beyond aggregate estimates, with many refinements and suggestions for future research.

Motion estimation is one of the most important steps in video compression algorithms. It reduces temporal redundancy present in frame sequences and allows a better compression of video material. Most of the actual video compression algorithms use "block matching" methods which operate on the bitmap form of the frames. Because real motion in video frames is not carried out over integer pixels, sub-pixel motion estimation is performed for improving the quality of the compression. Also, most of the video compression algorithms use discrete cosine transform for coding the residual frame information (in the motion compensation step). For this reason, motion estimation algorithms which operate directly in discrete cosine transform domain are of great interest. This paper presents a method for computing the values of DCT coefficients of a block of pixels positioned on certain coordinates over four adjacent blocks using only the DCT coefficients of these four blocks. Also, an equivalent of the full-search algorithm translated in 2D-DCT domain is presented.

This paper provides a dynamic analysis of the market for academic publications. Given imperfect information about journals' editorial line, authors can sometimes target a wrong journal; in turn, the editor will desk-reject their paper. An equilibrium is de…ned as a situation where both editors and authors implement their optimal publication strategies, given the matching technology and the prevailing surplus sharing rule. The model can be solved for the equilibrium submission fee, desk rejection rate and ratio between the number of editors and the number of authors.

Given the myriad of journal titles in economics and business administration, scholars can sometimes target the wrong journal. This paper provides a dynamic analysis of the market for academic publications that brings into the picture this type of informational friction. The key modelling device is a paper-tojournal matching function, similar to the matching function traditional in labor economics. An equilibrium is defined as a situation where both editors and authors implement their optimal publication strategies. The model is then solved for the equilibrium submission fee, desk rejection rate and ratio between the number of editors and the number of authors.

We investigate the practice of using probabilistically gen- erated melodies to do large scale evaluations of query-by- humming systems by running a set of sung queries against both real and synthetic databases, using an already verified type of "matching function" to map sung queries to the ap- propriate target. We find that the accuracy of the generative process can be improved by introducing a first-order Markov assumption into the model, though neither method of melodic generation is found to be a statistically consistant approxi- mation of an actual database under our experimental condi- tions.

This paper focuses on friction problems in the matching process arising in a dual labour market where good and bad jobs coexist. Specifically, we investigate the role of strong preferences for permanent contracts, in a labour market where also temporary contracts are offered, in increasing frictional unemployment. We use microdata from Portuguese job centres to estimate a reduced form equation of a matching function applying a competing risks discrete time hazard model that allows for stock-flow matching mechanism. Overall we find that, among unemployed flowing into temporary job, those looking for permanent contracts experience lower hazard rate, i.e. longer unemployment duration due to frictions deriving from contract mismatch. However, the effect tends to disappear controlling for a demand-side variable. Positive effects come from training activities are found, while job centres appear inadequate to favour the match for skilled workers. Policies aimed to reduce matching frictions and to improve labour market effectiveness should take care of that evidence and to increase the desirability of temporary contracts.

Semantic Web service discovery finds a match between service requirement and service advertisements based on the semantic description. The discovery mechanism does not consider quality and business offers of advertised Web services. In this paper, we propose ontology based Semantic Web service architecture for selection which recommends the best match for the requester. We design semantic broker which allows providers to advertise their services by creating OWLS service profile consisting of functional, quality and business offers. The broker computes and records information for matchmaking during service publishing to improve the performance. The broker reads requirements from the requester and finds the best (profitable) Web service by matching functionality, capability, quality and business offers.

Extraction of visual descriptors is a crucial problem for stateof-the-art visual information analysis. In this paper, we present a knowledgebased approach for detection of visual objects in video sequences, extraction of visual descriptors and matching with pre-defined objects. The proposed approach models objects through their visual descriptors defined in MPEG7. It first extracts moving regions using an efficient active contours technique. It then computes visual descriptions of the moving regions including color, motion and shape features that are invariant to affine transformations. The extracted features are matched to a-priori knowledge about the objects' descriptions, using appropriately defined matching functions. Results are presented which illustrate the theoretical developments.

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This Discussion Paper is issued within the framework of IZA’s research area The Welfare State and Labor Markets. Any opinions expressed here are those of the author(s) and not those of the institute. Research disseminated by IZA may include views on policy, but the institute itself takes no institutional policy positions. The Institute for the Study of Labor (IZA) in Bonn is a local and virtual international research center and a place of communication between science, politics and business. IZA is an independent, nonprofit limited liability company (Gesellschaft mit beschränkter Haftung) supported by the Deutsche Post AG. The center is associated with the University of Bonn and offers a stimulating research environment through its research networks, research support, and visitors and doctoral programs. IZA engages in (i) original and internationally competitive research in all fields of labor economics, (ii) development of policy concepts, and (iii) dissemination of research result...

FingerCode is a fingerprint correlation matching scheme that relies on texture information. In this scheme, the oriented components are extracted from a fingerprint image using a bank of Gabor filters, and a directional texture feature vector is computed for each oriented component. The feature vectors from the input and template images are compared and a matching score is obtained. Here we explore ways to improve the matching score for the FingerCode method by using more complex matching functions. The best results were obtained by applying a nonlinear function to the texture values and weighting the texture vectors based on the spatial distribution.

We investigated sexual and seasonal patterns in scent-marking behaviour of the honey badger, by direct observations of habituated individuals (five females, four adult males, two young males). Four categories of scent-marking behaviour were identified: (1) scent marking at latrines; (2) token urination in holes along the foraging path; (3) squat marking at single-use sites; and (4) functional excretion. Females and young males used all four types of scent marking, but adult males were not observed to use token urination. A strategy of hinterland scent marking was used, as was predicted from the large home ranges of both male and female honey badgers. There were significant sexual differences in marking rate: adult males primarily used latrines and adult females favoured token urination. Latrine scent marking in adult male honey badgers provides support for the 'scent-matching' hypothesis. Females visited latrines when they were in oestrus. However, the low level of marking activity during a visit and the intensive smelling suggested a scent-matching function rather than reproductive advertisement. Token urination appeared to be related to the maintenance of spatiotemporal separation in females, although we also observed token urination in young males. While the placement of urine in foraging holes and its relation with successful digging attempts offer some support for the foraging efficiency hypothesis, we consider this unlikely, because we did not observe it in adult males and there was no seasonal pattern. Squat marking occurred under a wide range of conditions in both males and females and may be related to marking valuable resources. It is likely that scent marking in honey badgers has many functions.

Service discovery is a key activity to actually identify the Web services (WSs) to be invoked and composed. Since it is likely that more than one service fulfill a set of user requirements, some ranking mechanisms based on non-functional properties (NFPs) are needed to support automatic or semi-automatic selection. This paper introduces an approach to NFP-based ranking of WSs providing support for semantic mediation, consideration of expressive NFP descriptions both on provider and client side, and novel matching functions for handling either quantitative or qualitative NFPs. The approach has been implemented in a ranker that integrates reasoning techniques with algorithmic ones in order to overcome current and intrinsic limitations of semantic Web technologies and to provide algorithmic techniques with more flexibility. Moreover, to the best of our knowledge, this paper presents the first experimental results related to NFP-based ranking of WSs considering a significant number of expressive NFP descriptions, showing the effectiveness of the approach.

We study the absolute and relative structure of Pareto-optimal allocation mechanisms in settings where the planner considers more than one objective criterion. Specifically, we (i) characterize mechanisms that implement the entire Pareto frontier (which cannot be done by maximizing weighted sums of the criteria) and (ii) study how these mechanisms change along the Pareto frontier (comparative statics). We apply our findings to common problems, such as allocation of a public resource according to allocative efficiency and consumer surplus. We show that selecting a point to implement on the Pareto frontier is equivalent to determining the extent of pooling. Implementing points with higher allocative efficiency requires pooling smaller subsets of agents in the set-inclusion order. Thus, consumer surplus can be seen as a proxy for distributional equality on the Pareto frontier. We also apply the findings to auction design, and provide comparative statics about the structure and the reserve price of optimal auctions.

Matching dependencies were recently introduced as declarative rules for data cleaning and entity resolution. Enforcing a matching dependency on a database instance identifies the values of some attributes for two tuples, provided that the values of some other attributes are sufficiently similar. Assuming the existence of matching functions for making two attributes values equal, we formally introduce the process of cleaning an instance using matching dependencies, as a chase-like procedure. We show that matching functions naturally introduce a lattice structure on attribute domains, and a partial order of semantic domination between instances. Using the latter, we define the semantics of clean query answering in terms of certain/possible answers as the greatest lower bound/least upper bound of all possible answers obtained from the clean instances. We show that clean query answering is intractable in some cases. Then we study queries that behave monotonically w.r.t. semantic domination order, and show that we can provide an under/over approximation for clean answers to monotone queries. Moreover, non-monotone positive queries can be relaxed into monotone queries.

Protein-protein interactions (PPIs) play a significant role in many crucial cellular operations such as metabolism, signaling and regulations. The computational methods for predicting PPIs have shown tremendous growth in recent years, but problem such as huge false positive rates has contributed to the lack of solid PPI information. We aimed at enhancing the overlap between computational predictions and experimental results in an effort to partially remove PPIs falsely predicted. The use of protein function predictor named PFP() that are based on shared interacting domain patterns is introduced in this study with the purpose of aiding the Gene Ontology Annotations (GOA). We used GOA and PFP() as agents in a filtering process to reduce false positive pairs in the computationally predicted PPI datasets. The functions predicted by PFP() were extracted from cross-species PPI data in order to assign novel functional annotations for the uncharacterized proteins and also as additional functions for those that are already characterized by the GO (Gene Ontology). The implementation of PFP() managed to increase the chances of finding matching function annotation for the first rule in the filtration process as much as 20%. To assess the capability of the proposed framework in filtering false PPIs, we applied it on the available S. cerevisiae PPIs and measured the performance in two aspects, the improvement made indicated as Signal-to-Noise Ratio (SNR) and the strength of improvement, respectively. The proposed filtering framework significantly achieved better performance than without it in both metrics.

Contrast matching was performed with isoluminant red-green and scone gratings at spatial frequencies ranging from 0.5 to 8 c/deg. Contrast threshold curves were low-pass in shape, in agreement with previous findings. Contrast matching functions resembled threshold curves at low contrast levels, but became flat and independent of spatial frequency at high contrasts. Thus, isoluminant chromatic gratings exhibited contrast constancy at suprathreshold contrast levels in a similar manner as has been demonstrated for achromatic gratings.

The contrast matching function (CMF) is the reciprocal of test contrast that perceptually matches the contrast of standard pattern, measured as a function of test spatial frequency (SF). Achromatic CMFs usually flatten as the contrast of the standard is raised, and are broader than the achromatic, bandpass, contrast sensitivity function (CSF). This report investigates whether chromatic CMFs have similar characteristics. For this purpose, the red-green color channel was defined using minimum flicker and hue cancellation techniques. Spatially localized (D6), vertical, equiluminant patterns (SFs: 0.063-8 cpd; contrast: 3-80%) were used to measure the CSF and CMF of isoluminant patterns presented with a temporal Gaussian envelope. CMFs were measured using a randomized double-staircase procedure and the two-interval forced choice technique. Two color-normal observers, whose task was to select the interval that had higher color contrast, participated in experiments. Results show that: (a) the color CMFs are lowpass functions of SF at low standard contrasts (3-12.5%), broad-bandpass at intermediate contrasts (6.25-60%), and near-flat at high contrasts (80%); and (b) isoluminant CMFs have higher upper cutoff frequencies than isoluminant CSFs. It is concluded that: (i) color-contrast-constancy (CMF independent of SF) is partly achieved at high contrasts because color CMFs flatten as contrast increases; (ii) the information processing at suprathreshold levels is different from that at the threshold levels; and (iii) the model that explained achromatic CMFs using achromatic threshold mechanisms could not explain chromatic CMFs using chromatic threshold mechanisms.

Our paper analyzes and compares two attempts at integrating unemployment in macroeconomics. The first, due to Peter Diamond, consists in a search model exhibiting multiple equilibria and wherein cycles may be produced. The second is due to David Andolfatto and Monika Merz, who, more or less simultaneously, constructed models enabling the integration of the matching function into RBC modeling. In the first sections, we present the methodology upon which our paper is based—Axel Leijonhufvud’s decision-tree insight—and briefly describe these three economists’ motivations and the context in which they were working. We continue with recounting the birth and further development of the search paradigm upon which Diamond’s, Andolfatto’s, and Merz’s attempts were based. These preliminaries settled, we address the heart of the paper, the critical analysis of their respective contributions. Our interest lies specifically in how they made their way in the development of the field. We explain wh...

This paper is concerned with the effect of the unemployment insurance system and of training programs on unemployment outflow rates disaggregated by sex and two unemployment duration categories. The model is based on a matching function and ...

It has been predicted, both theoretically and by computer simulation, that in capillary electrophoresis the electromigration-dispersion-induced peak broadening can be eliminated by matching the mobilities of the analyte and the background electrolyte co-ion. Though mobility matching can be achieved by invoking multiple secondary chemical equilibria in the background electrolyte-such as protonation or complexation-to change the mobility of the co-ion, this approach is not feasible when the composition of the background electrolyte is dictated by the need to achieve a certain separation selectivity. In this paper, a background electrolyte preparation principle is outlined which decouples the dual roles of the background electrolyte, namely the buffering function and the mobility matching function, by ascribing the buffering function solely to the counter-ion (a conjugate acid or conjugate base) and the mobility matching function solely to the co-ion (a strong electrolyte). The power of this approach is demonstrated by solving difficult enantiomer separations.

Cet article decrit une contrainte d'un modele de recherche d'information decrivant les comportement attendu d'un systeme si un document du corpus est pose en requete, la contrainte DDMC (Document-Document Matching Constraint). Cette contrainte n'etant pas verifiee par un modele classique de recherche d'information (modele de langue base sur un calcul de nega-tive de Divergence de Kullback-Leibler avec lissage de Jelinek-Mercer), nous presentons une modification de ce dernier modele qui permet de verifier DDMC. Une derniere partie presente des experimentations menees afin de verifier que notre modification n'impacte pas la qualite des reponses d'un systeme, tout en garantissant la verification de DDMC.

We investigate job competition among job seekers and vacancy competition among firms extending the job competition model proposed by Anderson and Burgess (Anderson, P.M., Burgess, S.M., 2000. Empirical matching functions: Estimation and interpretation using state level data. Review of Economics and Statistics 82, p. 90-102). Our results for data from West Germany provide evidence for both phenomena, thereby extending and qualifying previous insights.

Starting in January 2003, Germany implemented the first two so-called Hartz reforms, followed by the third and fourth packages of Hartz reforms in January 2004 and January 2005, respectively. The aim of these reforms was to accelerate labor market flows and reduce unemployment duration.Without attempting to evaluate the specific components of these Hartz reforms, this paper provides a first attempt to evaluate the overall effectiveness of the first two reform waves, Hartz I/II and III, in speeding up the matching process between unemployed and vacant jobs. The analysis is conceptually rooted in the flow-based view underlying the reforms, estimating the structural features of the matching process. The results indicate that the reforms indeed had an impact in making the labor market more dynamic and accelerating the matching process.