Az innováció és a termelékenység közötti vállalati szintű kapcsolat elemzésekor az exporton kívül az importot is figyelembe kell venni. Az innováció pozitívan hat a termelékenységre, ugyanakkor a hatás mértéke időben változott. Az innováció termelékenységre kifejtett becsült hatása 2010-ig nőtt, utána csökkent és 2016-ra visszaesett a 2005. évi szintre. Ezt a hatást felerősítette az, hogy 2010 után folyamatosan és jelentősen csökkent az innovatív vállalatok aránya.

Since trust correlates with economic development and in turn economic development associates with political regime, we conjecture that there may be a relationship between trust and political regime. We investigate if trust aggregated on the country level correlates with the political regime. We do not find any significant association, with or without taking into account other factors (e.g. regional location, economic development, geographic conditions, culture) as well.

We test if the political regime of a country associates with the patience of the citizens. Recent findings indicate that i) more democratic countries tend to have higher growth, and ii) patience correlates positively with economic development, suggesting a potential link between the political regime and patience. We document a positive association between the level of democracy and patience for most of the political regime indices that we use, even after controlling for region, economic development, geographical conditions, and culture. We report some evidence that political participation is behind our findings.

The paper discusses the economic aspects of the most important questions (such as demand response or capacity allocation) related to differential pricing. First, we consider a revenue-neutral introduction of peak-load pricing. We examine under what circumstances does peak-load pricing lead to a Pareto improvement compared to uniform pricing. Second, we analyze what properties of customers make it profitable for a firm to introduce peak-load pricing. We find that on the supply side, incentives to introduce differential pricing may be technology-driven (i. e. high on-peak marginal costs) or demand-driven (i.e. low elasticity of substitution). Consumers benefit more if they can adopt to prices more flexibly. Innovative technology, such as smart meters, may help consumers benefit from real-time pricing. Such technology is expensive to install. This makes it necessary that consumers cover part of the costs. If they are myopic, or other effects of bounded rationality hinder their commitment, regulatory intervention might be needed to increase welfare. The more accessible enabling technology (price comparison websites, cheap smart meters etc.) will be, the more everyone will benefit from time-varying pricing.

In recent years public and political debate suggested that individuals with chil- dren value the future more. We attempt to substantiate the debate and using a representative survey we investigate if the number of children (or simply having children) indeed is associated with a higher valuation of the future that we proxy with an aspect of time preferences, patience. We find that in general there is no correlation between having children and patience, though for young women with below-median income we find some weak evidence in line with the conjecture. We also show some evidence that for this subpopulation it is not having children that matters, but marital status. More precisely, young single women are less patient than other young non-single women.

Sum of Ranking Differences is an innovative statistical method that ranks competing solutions based on a reference point. The latter might arise naturally, or can be aggregated from the data. We provide two case studies to feature both possibilities. Apportionment and districting are two critical issues that emerge in relation to democratic elections. Theoreticians invented clever heuristics to measure malapportionment and the compactness of the shape of the constituencies, yet, there is no unique best method in either cases. Using data from Norway and the US we rank the standard methods both for the apportionment and for the districting problem. In case of apportionment, we find that all the classical methods perform reasonably well, with subtle but significant differences. By a small margin the Leximin method emerges as a winner, but — somewhat unexpectedly — the non-regular Imperiali method ties for first place. In districting, the Lee-Sallee index and a novel parametric method the so-called Moment Invariant performs the best, although the latter is sensitive to the function’s chosen parameter.

We show how frictions and continuous transfers jointly affect equilibria in a model of matching in trading networks. Our model incorporates distortionary frictions such as transaction taxes, bargaining costs, and incomplete markets. When contracts are fully substitutable for firms, competitive equilibria exist and coincide with outcomes that satisfy a cooperative stability property called trail stabity. In the presence of frictions, competitive equilibria might be neither stable nor (constrained) Pareto-efficient. In the absence of frictions, on the other hand, competitive equilibria are stable and in the core, even if utility is imperfectly transferable.

In the stable marriage problem, a set of men and a set of women are given, each of whom has a strictly ordered preference list over the acceptable agents in the opposite class. A matching is called stable if it is not blocked by any pair of agents, who mutually prefer each other to their respective partner. Ties in the preferences allow for three different definitions for a stable matching: weak, strong and super-stability. Besides this, acceptable pairs in the instance can be restricted in their ability of blocking a matching or being part of it, which again generates three categories of restrictions on acceptable pairs. Forced pairs must be in a stable matching, forbidden pairs must not appear in it, and lastly, free pairs cannot block any matching.

We study the classical, two-sided stable marriage problem under pairwise preferences. In the most general setting, agents are allowed to express their preferences as comparisons of any two of their edges and they also have the right to declare a draw or even withdraw from such a comparison. This freedom is then gradually restricted as we specify six stages of orderedness in the preferences, ending with the classical case of strictly ordered lists. We study all cases occurring when combining the three known notions of stability—weak, strong and super-stability—under the assumption that each side of the bipartite market obtains one of the six degrees of orderedness. By designing three polynomial algorithms and two NP-completeness proofs we determine the complexity of all cases not yet known, and thus give an exact boundary in terms of preference structure between tractable and intractable cases.

Our input is a complete graph G on n vertices where each vertex has a strict ranking of all other vertices in G. The goal is to construct a matching in G that is “globally stable” or popular. A matching M is popular if M does not lose a head-to-head election against any matching M’: here each vertex casts a vote for the matching in {M,M’} in which it gets a better assignment. Popular matchings need not exist in the given instance G and the popular matching problem is to decide whether one exists or not. The popular matching problem in G is easy to solve for odd n. Surprisingly, the problem becomes NP-hard for even n, as we show here. This seems to be the first graph theoretic problem that is efficiently solvable when n has one parity and NP-hard when n has the other parity.

Our input is a complete graph G on n vertices where each vertex has a strict ranking of all other vertices in G. The goal is to construct a matching in G that is “globally stable” or popular. A matching M is popular if M does not lose a head-to-head election against any matching M’: here each vertex casts a vote for the matching in {M,M’} in which it gets a better assignment. Popular matchings need not exist in the given instance G and the popular matching problem is to decide whether one exists or not. The popular matching problem in G is easy to solve for odd n. Surprisingly, the problem becomes NP-hard for even n, as we show here. This seems to be the first graph theoretic problem that is efficiently solvable when n has one parity and NP-hard when n has the other parity.

An instance of the marriage problem is given by a graph G together with, for each vertex of G, a strict preference order over its neighbors. A matching M of G is popular in the marriage instance if M does not lose a head-to-head election against any matching where vertices are voters. Every stable matching is a min-size popular matching; another subclass of popular matchings that always exist and can be easily computed is the set of dominant matchings. A popular matching M is dominant if M wins the head-to-head election against any larger matching. Thus every dominant matching is a max-size popular matching and it is known that the set of dominant matchings is the linear image of the set of stable matchings in an auxiliary graph. Results from the literature seem to suggest that stable and dominant matchings behave, from a complexity theory point of view, in a very similar manner within the class of popular matchings.

The goal of this paper is to show that indeed there are differences in the tractability of stable and dominant matchings, and to investigate further their importance for popular matchings. First, we show that it is easy to check if all popular matchings are also stable, however it is co-NP-hard to check if all popular matchings are also dominant. Second, we show how some new and recent hardness results on popular matching problems can be deduced from the NP-hardness of certain problems on stable matchings, also studied in this paper, thus showing that stable matchings can be employed not only to show positive results on popular matching (as is known), but also most negative ones. Problems for which we show new hardness results include finding a min-size (resp. max-size) popular matching that is not stable (resp. dominant). A known result for which we give a new and simple proof is the NP-hardness of finding a popular matching when G is non-bipartite.