1,316 research outputs found
Unemployment Insurance Savings Accounts
We examine a system of Unemployment Insurance Saving Accounts (UISAs) as an alternative to the traditional unemployment insurance system. Individuals are required to save up to 4 percent of wages in special accounts and to draw unemployment compensation from these accounts instead of taking state unemployment insurance benefits. If the accounts are exhausted, the government lends money to the account. Positive accounts earn the return on commercial paper and negative accounts are charged that rate. Positive UISA balances are converted into retirement income or bequeathed if the individual dies before retirement age. Negative account balances are forgiven at retirement age. Money taken by an unemployed individual from a UISA with a positive balance reduces the individual's personal wealth by an equal amount. In this case, individuals fully internalize the cost of unemployment compensation. UISAs provide the same protection to the unemployed as the current UI system but with less of the adverse incentives. The key empirical question is whether accounts based on a moderate saving rate can finance a significant share of unemployment payments or whether the concentration of unemployment among a relatively small number of individuals implies that the UISA balances would typically be negative, forcing individuals to rely on government benefits with the same adverse effects that characterize the current UI system. To resolve this issue we use the Panel Study on Income Dynamics to simulate the UISA system over a 25 year historic period. Our analysis indicates that almost all individuals have positive UISA balances and therefore remain sensitive to the cost of unemployment compensation. Even among individuals who experience unemployment, most have positive account balances at the end of their unemployment spell. Although about half of the benefit dollars would go to individuals whose accounts are negative at the end of their working life, less than one third of the benefits go to individuals who also have negative account balances when unemployed. These facts suggest a substantial potential improvement in the incentives of the unemployed. The cost to taxpayers of forgiving the negative balances is substantially less than half of the taxpayer cost of the current UI system. Our analysis of the distribution of lifetime UISA payments and taxes of household heads shows the top quintile gaining a small cumulative amount while those in the bottom quintile lose a very small cumulative amount. Other quintiles are small net gainers.
Are International Differences in Living Standards Really So Hard to Explain?
A cross-country regression using only a handful of deeply rooted
explanatory variables accounts for 80 percent of the variation in living
standards across countries. Most of the biggest residuals from the
regression can also be explained, at least partially, with rudimentary
facts about the associated countries. What remains may be a useful
indicator of a country’s openness and innovative capacity
throughout its economic history
Enrollee Mix, Treatment Intensity, and Cost in Competing Indemnity and HMO Plans
We examine why managed care plans are less expensive than traditional indemnity insurance plans. Our database consists of the insurance experiences of over 200,000 state and local employees in Massachusetts and their families, who are insured in a single pool. Within this group, average HMO costs are 40 percent below those of the indemnity plan. We evaluate cost differences for 8 conditions representing over 10 percent of total health expenditures. They are: heart attacks, cancers (breast, cervical, colon, prostate), diabetes (type I and II), and live births. For each condition, we identify the portions of the cost differential arising from differences in treatment intensity, enrollee mix, and prices paid for the same treatment. Surprisingly, treatment intensity differs hardly at all between the HMOs and the indemnity plan. That is, relative to their fee-for-service competitor, HMOs do not curb the use of expensive treatments. Across the 8 conditions, roughly half of the HMO cost savings is due to the lower incidence of the diseases in the HMOs. Virtually all of the remaining savings come because HMOs pay lower prices for the same treatment.
Topics in and around higher-order Fourier analysis
We present some results in both the theory and application of higher-order Fourier analysis.
In Chapters 1 and 2 we give background and context to the study of higher-order Fourier analysis, and to the questions and problems addressed in this thesis.
Gowers and Wolf conjectured that, given a set of linear forms {Ïi}ti=1 each mapping ZD to Z, if s is an integer such that the functions Ïs+1i, . . . , Ïs+1t are linearly independent, then averages of the form ExQti=1 f(Ïi(x)) may be controlled by the Gowers Us+1-norm of f. In Chapter 3 we prove (a stronger version of) this conjecture. This chapter appears in the literature as [2].
Green and Taoâs arithmetic regularity lemma and counting lemma together apply to systems of linear forms which satisfy a particular algebraic criterion known as the âflag conditionâ. In Chapter 4 we give an arithmetic regularity lemma and counting lemma which applies to all systems of linear forms and provide a couple ofapplications. This chapter appears on the arXiv as [5].
In Chapter 5 we consider SzemerÂŽediâs theorem on k-term arithmetic progressions where the set S of allowed common differences in those progressions is restricted to a set which is chosen randomly. We show that the threshold over finite fields is different to the conjectured threshold over the integers. This chapter appears in the literature as [3].
A system of linear equations in F np is Sidorenko if any subset of Fnp contains at least as many solutions to the system as a random set of the same density, asymptotically as n â â. A system of linear equations in Fnp is common if every two-colouring of Fnp yields at least as many monochromatic solutions as a random two-colouring, asymptotically as n â â. By analogy to the graph-theoretic setting, Alon has asked whether any (non-Sidorenko) system of linear equations can be made uncommon by adding sufficiently many free variables. Fox, Pham and Zhao answered this question in the affirmative among systems which consist of a single equation. In Chapter 6 we answer Alonâs question in the negative. Here we also observe that the property of remaining common despite that addition of arbitrarily many free variables is closely related to a notion of commonness in which one replaces the arithmetic mean of the number of monochromatic solutions with the geometric mean, and furthermore resolve questions of KamËcevâLiebenauâMorrison. This chapter appears on the arXiv as [6].
In Chapter 7 we show that a certain generic family of systems of two linear equations is not Sidorenko. In fact, we show that systems in this family are not locally Sidorenko, and that systems in this family which do not contain additive tuples are not weakly locally Sidorenko. This endeavour answers a conjecture and question of KamËcevâLiebenauâMorrison. Insofar as methods are concerned, we observe that the true complexity of a linear system is not maintained under Fourier inversion; our main novelty is the use of higher-order methods in the frequency space of systems which have complexity one. We also give a shorter proof of the recent result of KamËcevâ LiebenauâMorrison and independently Versteegen that any linear system containing a four-term arithmetic progression is uncommon. This chapter appears on the arXiv as [4]
Forever Young: Aging Control For Smartphones In Hybrid Networks
The demand for Internet services that require frequent updates through small
messages, such as microblogging, has tremendously grown in the past few years.
Although the use of such applications by domestic users is usually free, their
access from mobile devices is subject to fees and consumes energy from limited
batteries. If a user activates his mobile device and is in range of a service
provider, a content update is received at the expense of monetary and energy
costs. Thus, users face a tradeoff between such costs and their messages aging.
The goal of this paper is to show how to cope with such a tradeoff, by devising
\emph{aging control policies}. An aging control policy consists of deciding,
based on the current utility of the last message received, whether to activate
the mobile device, and if so, which technology to use (WiFi or 3G). We present
a model that yields the optimal aging control policy. Our model is based on a
Markov Decision Process in which states correspond to message ages. Using our
model, we show the existence of an optimal strategy in the class of threshold
strategies, wherein users activate their mobile devices if the age of their
messages surpasses a given threshold and remain inactive otherwise. We then
consider strategic content providers (publishers) that offer \emph{bonus
packages} to users, so as to incent them to download updates of advertisement
campaigns. We provide simple algorithms for publishers to determine optimal
bonus levels, leveraging the fact that users adopt their optimal aging control
strategies. The accuracy of our model is validated against traces from the
UMass DieselNet bus network.Comment: See also http://www-net.cs.umass.edu/~sadoc/agecontrol
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