Asymptotics of the L^2 Norm of Derivatives of OPUC

We show that for many families of OPUC, one has $||\varphi'_n||_2/n -> 1$, a condition we call normal behavior. We prove that this implies $|\alpha_n| -> 0$ and that it holds if the sequence $\alpha_n$ is in $\ell^1$. We also prove it is true for many sparse sequences. On the other hand, it is often destroyed by the insertion of a mass point.Comment: 36 pages, no figures. Minor corrections, to appear in the Journal of Approximation Theor

Why is unemployment low in the former Soviet Union? : enterprises restructuring and the structure of compensation

The authors explain why in the Former Soviet Union (FSU) - especially Russia - unemployment has remained low and employment in state and privatized firms has remained high, while at the same time the informal or unofficial economy has grown swiftly. They trace this development to a combination of factors, including the control regime of state and privatized firms, the nature of worker compensation, and privatized firms, and the nature of subsidies or financial supports that firms continue to receive. Firms have remained the primary site for social protection. Subsidies for social benefits have effectively been a subsidy to employment and have promoted the workers'continuing attachment to these firms. Partly because the subsidies still flow and partly because of the firms'internal control structure, firms have held back on shedding labor. Firms typically work at low capacity. Instead of laying workers off, they significantly cut hours and wages, sometimes through wage arrears. The share of worker compensation that is nonmonetary had grown during the transition, and is significant. So workers search for additional sources of income, either moonlight or get involved in the informal economy. Why has this happened? Privatization has so far failed to keep firms from behaving as if they have important social responsibilities. Managers may have more discretion in decisionmaking, but seem tobe reluctant to fire workers. This reluctance reflects various pressures, including insider coalitions and pressure from local and federal governments to limit the flow to unemployment. One factor may be the need to keep workers cooperative and possibly repel outsider interest. And in the FSU, many firms continue to operate under soft budget constraints, so they are under less pressure to reduce employment levels than firms in Eastern and Central Europe. The authors show that under certain conditions if the subsidy to insider-dominated firms disappears, those firms will scale down employment and the provision of benefits. In a firm with two divisions - one that produces and one that provides benefits - the dominant (producing ) division will tend to close down the benefits-providing division if the firm assumes a simple majority decision rule.Economic Theory&Research,Municipal Financial Management,Decentralization,Environmental Economics&Policies,Banks&Banking Reform,Economic Theory&Research,Environmental Economics&Policies,Health Monitoring&Evaluation,Banks&Banking Reform,Municipal Financial Management

Restructuring and taxation in transition economies

One challenge in transition economies has been to avoid being caught between overrapid restructuring (harmful to the private sector) and gradual change (can undermine robust private sector emergence). Empirical evidence suggests thatin most of Eastern Europe and the former Soviet Union, insiders, by exerting decision making control, have materially affected the restructuring rate. Still, shocks to firms have generally led to sharp rises in unemployment. Unemployment benefits, initially generous, combined with lost payroll taxes substantially increased fiscal costs. In the former Soviet Union, both restructuring and unemployment have remained limited and firm subsidies remained high. The private sector expanded, but chiefly in the gray (untaxed) part of the economy. The authors examine the implications of various restructuring speeds, explicitly introducing probabilities of closure and restructuring. They find that when the probability of closure is small, unemployment will peak at a lower level than when the probability of closure is high, although the transition speed will be much slower. They also find that widespread private sector tax avoidance can stimulate that sector's growth and result in a speedier transition. Thus, while a private sector low tax burden can drive unemployment up rapidly by increasing the state sector closure probability, it can also help speed up the transition by provoking a quicker private sector response. The authors show that while the state sector restructuring speed is sensitive to the tax burden, (dependent on unemployment and the ability to tax the private sector) it is also true that the private sectors growth depends on the tax burden it faces. In particular, capturing the private sector in the tax net early in the transition can lead to collapse and hence to the failure of restructuring.Trade Finance and Investment,Health Monitoring&Evaluation,Economic Theory&Research,Public Health Promotion,Environmental Economics&Policies,National Governance,Youth and Governance,Health Monitoring&Evaluation,Economic Theory&Research,Environmental Economics&Policies

Poncelet's Theorem, Paraorthogonal Polynomials and the Numerical Range of Compressed Multiplication Operators

There has been considerable recent literature connecting Poncelet's theorem to ellipses, Blaschke products and numerical ranges, summarized, for example, in the recent book [11]. We show how those results can be understood using ideas from the theory of orthogonal polynomials on the unit circle (OPUC) and, in turn, can provide new insights to the theory of OPUC.Comment: 46 pages, 4 figures; minor revisions from v1; accepted for publication in Adv. Mat

The Unofficial Economy in Transition

macroeconomics, official economy, public finances, economic growth

Cell death and life in cancer: mathematical modeling of cell fate decisions

Tumor development is characterized by a compromised balance between cell life and death decision mechanisms, which are tighly regulated in normal cells. Understanding this process provides insights for developing new treatments for fighting with cancer. We present a study of a mathematical model describing cellular choice between survival and two alternative cell death modalities: apoptosis and necrosis. The model is implemented in discrete modeling formalism and allows to predict probabilities of having a particular cellular phenotype in response to engagement of cell death receptors. Using an original parameter sensitivity analysis developed for discrete dynamic systems, we determine the critical parameters affecting cellular fate decision variables that appear to be critical in the cellular fate decision and discuss how they are exploited by existing cancer therapies

Regional Differences in the Tourism of the South – Muntenia Development Region

The South-Muntenia Development Region can be characterized by major differences between the districts that compose it. This situation reverberates on the level of the tourist activity, from tourist potential point of view, as well as technical and town endowment or tourist traffic. The biggest differences are between the north district, more developed from tourist point of view, being helped by the variety of the relief’s aspect, and the ones from the south of the region, that are not so developed, with a small landscape architecture and investment attractiveness

Coase v. the Coasians

The Coase theorem implies that, in a world of positive transaction costs, any of a number of strategies, including judicially enforced private contracts, judicially enforced laws, or even government regulation, may be the cheapest way to bring about efficient resource allocation. Unfortunately, some Coasians have ignored the possibility that the last of these strategies may sometimes be the best. This paper compares the regulation of financial markets in Poland and the Czech Republic in the 1990s, when the judicial systems remained underdeveloped in both countries. In Poland, strict enforcement of the securities law by an independent Securities and Exchange Commission was associated with rapid development of the stock market. In the Czech Republic, hands-off regulation was associated with a near collapse of the stock market. These episodes illustrate the centrality of law enforcement in making markets work, and the possible role of regulators in law enforcement.