Limit theory for panel data models with cross sectional dependence and sequential exogeneity

The paper derives a general Central Limit Theorem (CLT) and asymptotic distributions for sample moments related to panel data models with large n$n$. The results allow for the data to be cross sectionally dependent, while at the same time allowing the regressors to be only sequentially rather than strictly exogenous. The setup is sufficiently general to accommodate situations where cross sectional dependence stems from spatial interactions and/or from the presence of common factors. The latter leads to the need for random norming. The limit theorem for sample moments is derived by showing that the moment conditions can be recast such that a martingale difference array central limit theorem can be applied. We prove such a central limit theorem by first extending results for stable convergence in Hall and Heyde (1980) to non-nested martingale arrays relevant for our applications. We illustrate our result by establishing a generalized estimation theory for GMM estimators of a fixed effect panel model without imposing i.i.d. or strict exogeneity conditions. We also discuss a class of Maximum Likelihood (ML) estimators that can be analyzed using our CLT.     

When do Non‐Family CEOs Outperform in Family Firms? Agency and Behavioural Agency Perspectives

Family firms represent a globally dominant form of organization, yet they confront a steep challenge of finding and managing competent leaders. Sometimes, these leaders cannot be found within the owning family. To date we know little about the governance contexts under which non‐family leaders thrive or founder. Guided by concepts from agency theory and behavioural agency theory, we examine the conditions of ownership and leadership that promote superior performance among non‐family CEOs of family firms. Our analysis of 893 Italian family firms demonstrates that these leaders outperform when they are monitored by multiple major family owners as opposed to a single owner; they also outperform when they are not required to share power with co‐CEOs who are family members, and who may be motivated by parochial family socioemotional priorities.     

The dynamics of parallel economies. Measuring the informal sector in Mexico

The existence of parallel economies that operate in the shadows of informality within most Latin American countries is widely recognized by the economic literature. However, its composition, size and effects on economic growth are still open questions. In this paper, we estimate the size and the evolution of the Mexican informal economy in the last three decades using a vector error correction model. In addition to the standard explanatory variables traditionally used in the currency demand approach, we include remittances given their relevance in the Mexican economic system. The results indicate that informality prior to the late 1980s accounted for at least two thirds of GDP, while stabilizing around one third of GDP in the last decade. Furthermore, our estimates provide evidence of a positive long-run relationship between informality and economic growth.     

Would you like to shrink the welfare state? A survey of European citizens

The fundamental problems facing European welfare states – high unemployment and unsustainable public pensions plans in particular – have been in the political debate for years, so why have we seen so little reform? To find out, we surveyed the opinions of citizens in France, Germany, Italy and Spain on their welfare states and on various reform options. This is what we found. First, most workers underestimate the costs of public pensions, though they are aware of their unsustainability. Second, the status quo is a majoritarian outcome: a majority of citizens opposes cuts to social security and welfare spending, but also opposes further increases. Since population ageing without reform implies an automatic expansion, our results suggest that most citizens would favour reforms that stabilize but do not shrink the current welfare states. Third, many would welcome changes in the allocation of benefits. A large number of workers in Italy and Germany would be willing to opt out of public pensions and replace them with private pensions, though the details of how this scheme is formulated matter for its popularity. And many Italians and Spaniards would welcome an extension of the coverage of unemployment insurance. Fourth, conflicts over the welfare state are mainly shaped by the economic situation of the respondent, while political ideology plays a limited role. Disagreements are found along three dimensions: young versus old, rich versus poor, and 'outsider' versus 'insider' in terms of labour market status. From a practical point of view, this suggests that there is scope to bundle reforms strategically in order to build a large and mixed coalition of supporters.
— Tito Boeri, Axel Börsch-Supan and Guido Tabellini     

The generalized bin packing problem

In the Generalized Bin Packing Problem (GBPP), given two sets of compulsory and non-compulsory items characterized by volume and profit and a set of bins with given volume and cost, we want to select the subset of profitable non-compulsory items to be loaded together with the compulsory ones into the appropriate bins in order to minimize the total net cost. Lower and upper bounds to the GBPP are given. The results of extensive computational experiments show that the proposed procedures are efficient and the bounds are tight.     

HETEROGENEOUS LABOUR,SCARCITY AND CHOICE OF TECHNIQUES

A Sraffian model is presented in which commodities are produced by means of heterogeneous labour, and wages are (partially) determined by scarcity. Demand is explicitly taken into account, and therefore a “choice of techniques” perspective is adopted. It is shown that demand influences the choice of the cost-minimizing technique, and that the cost-minimizing technique may not always be unique. A dynamic extension of the model is briefly discussed. A numerical example illustrates how systems might behave over time.     

Two measures of organizational flexibility

Since the second half of the past century, increasingly flexible organizational forms have been appearing among firms. However, while hierarchies are easily described, too few mathematical tools are available for flexible organizations. In this article, two measures are proposed in order to assess the state and trend of flexible organizations. The first of these measures is based on information waste, which occurs whenever information is classified into categories. The second measure is based on duplication of operations. The underlying idea is that firms have an endogenous drive towards organizational configurations where waste of information and duplication of operations are minimized. However, environmental uncertainty may require some flexibility, which is ensured by cognitive processes that discard some information as well as by parallel undertaking of similar actions.     

Does intellectual monopoly stimulate or stifle innovation?

This study develops an R&D-based growth model with vertical and horizontal innovation to shed some light on the current debate on whether patent protection stimulates or stifles innovation. We analyze the effects of patent protection in the form of blocking patents. We show that patent protection changes the direction of innovation by having asymmetric effects on vertical innovation (i.e., quality improvement) and horizontal innovation (i.e., variety expansion). Calibrating the model and simulating transition dynamics, we find that strengthening the effect of blocking patents stifles vertical innovation and decreases economic growth but increases social welfare due to an increase in horizontal innovation. In light of this finding, we argue that in order to properly analyze the growth and welfare implications of patents, it is important to consider their often neglected compositional effects on vertical and horizontal innovation.     

Europe’s energy policy and the task ahead

The oil shock of 1973 and the subsequent world recession have drastically demonstrated the weakness of countries dependent on external energy supplies. In the following, Guido Brunner, the competent Member of the Commission of the European Communities, describes the changes we are facing in the energy field and what the Community is doing to face up to them.