Storing and Indexing Plan Derivations through Explanation-based Analysis of Retrieval Failures

Case-Based Planning (CBP) provides a way of scaling up domain-independent planning to solve large problems in complex domains. It replaces the detailed and lengthy search for a solution with the retrieval and adaptation of previous planning experiences. In general, CBP has been demonstrated to improve performance over generative (from-scratch) planning. However, the performance improvements it provides are dependent on adequate judgements as to problem similarity. In particular, although CBP may substantially reduce planning effort overall, it is subject to a mis-retrieval problem. The success of CBP depends on these retrieval errors being relatively rare. This paper describes the design and implementation of a replay framework for the case-based planner DERSNLP+EBL. DERSNLP+EBL extends current CBP methodology by incorporating explanation-based learning techniques that allow it to explain and learn from the retrieval failures it encounters. These techniques are used to refine judgements about case similarity in response to feedback when a wrong decision has been made. The same failure analysis is used in building the case library, through the addition of repairing cases. Large problems are split and stored as single goal subproblems. Multi-goal problems are stored only when these smaller cases fail to be merged into a full solution. An empirical evaluation of this approach demonstrates the advantage of learning from experienced retrieval failure.Comment: See http://www.jair.org/ for any accompanying file

Changes to the Tax Exclusion of Employer-Sponsored Health Insurance Premiums: A Potential Source of Financing for Health Reform

Examines eight options for limiting the tax exclusion of employer-sponsored health insurance premiums. Compares, by income level, estimated effects of various caps and indices on tax revenues and after-tax incomes in the first year and over ten years

Design reuse research : a computational perspective

This paper gives an overview of some computer based systems that focus on supporting engineering design reuse. Design reuse is considered here to reflect the utilisation of any knowledge gained from a design activity and not just past designs of artefacts. A design reuse process model, containing three main processes and six knowledge components, is used as a basis to identify the main areas of contribution from the systems. From this it can be concluded that while reuse libraries and design by reuse has received most attention, design for reuse, domain exploration and five of the other knowledge components lack research effort

Income Tax Incentives to Promote Saving

We examine six alternative plans which might be discussed in an effort to increase consumer savings through the personal income tax system in the United States. These plans attempt to affect savings through an increase in the real rate of return either by direct tax cuts on savings or by indexing tax rates against inflation. The paper presents estimates of static and dynamic resource allocation effects for the six plans, and compares them to results obtained in earlier work on the impacts of more sweeping reforms. A medium-scale numerical general equilibrium model is used which integrates the U. S. tax system with consumer demand behavior by household and producer behavior by industry.

Limiting the Tax Exclusion of Employer-Sponsored Health Insurance Premiums: Revenue Potential and Distributional Consequences

Serious efforts to forge a budget agreement in 2013 will increase the likelihood that lawmakers will seek changes to tax provisions in order to raise revenue. The exclusion of employer-sponsored health insurance premiums and medical benefits from taxable income could be a target, since this exclusion reduced federal tax revenues by $268 billion in 2011 alone -- by far the largest federal tax expenditure. Moreover, the exclusion disproportionately subsidizes those with higher incomes. Yet proposals to change the tax exclusion of employer-sponsored insurance have provoked intense debate. This brief provides estimates of the revenue potential and distributional consequences of a new policy option. The policy analyzed here would impose a cap, or dollar limit, on the aggregate cost of employer-sponsored health coverage excluded from income and payroll taxes. The cap would be set at the 75th percentile of the sum of premiums and other medical benefits, and would be indexed, or allowed to grow over time, by a five-year average of the rate of GDP growth. The goal in choosing the level and indexing for the cap was to select a policy that would make a significant contribution to debt reduction, but would be distributionally equitable. This brief answers four critical questions related to the 75th percentile cap on the exclusion of premium and medical benefits:What are the estimated new tax revenues related to this policy in 2014 and 2014 -- 2023?How many people would pay higher taxes in each quintile of income?How much would taxes increase for those paying higher taxes?What are the characteristics of employers whose employees are likely to pay higher taxes?The evidence shows that the 75th percentile tax cap would produce$264.0 billion in new income and payroll tax revenues over the coming decade while still preserving 93 percent of the tax subsidies available under the current policy. Across all tax units, 15.7 percent would pay higher taxes under the 75th percentile cap on the exclusion of premium and medical benefits in 2014, with this share increasing to 20.0 percent by 2023. Although tax units across the entire income distribution would experience some tax increases, these increases are considerably smaller and less prevalent at lower income levels. The policy change would affect public-sector employees to a greater extent than private-sector employees. In addition, among private-sector employees, those in the financial services/real estate or professional services industries would be affected to a greater extent, while employees in other industries such as the retail industry, would be affected to a lesser extent. Establishments with a union presence have only a modestly higher share of employees with premiums above the 75th percentile premium, compared to the average across all establishments

A Timeline of the Evolution of Retirement in the United States

This document provides key highlights in the history of retirement in the United States. It provides some background on how the concept of retirement, and its legal treatment, has evolved. This time-line does not include every law related to pension and retirement plans. Rather, it emphasizes those laws that have come to shape how we view retirement, particularly the tax laws that encouraged employers to establish pension and retirement plans in the first place

Massively parallel support for a case-based planning system

Case-based planning (CBP), a kind of case-based reasoning, is a technique in which previously generated plans (cases) are stored in memory and can be reused to solve similar planning problems in the future. CBP can save considerable time over generative planning, in which a new plan is produced from scratch. CBP thus offers a potential (heuristic) mechanism for handling intractable problems. One drawback of CBP systems has been the need for a highly structured memory to reduce retrieval times. This approach requires significant domain engineering and complex memory indexing schemes to make these planners efficient. In contrast, our CBP system, CaPER, uses a massively parallel frame-based AI language (PARKA) and can do extremely fast retrieval of complex cases from a large, unindexed memory. The ability to do fast, frequent retrievals has many advantages: indexing is unnecessary; very large case bases can be used; memory can be probed in numerous alternate ways; and queries can be made at several levels, allowing more specific retrieval of stored plans that better fit the target problem with less adaptation. In this paper we describe CaPER's case retrieval techniques and some experimental results showing its good performance, even on large case bases

Does Participating in a 401(k) Raise Your Lifetime Taxes?

Contributing to 401(k)s and similar tax-deferred retirement accounts certainly lowers current taxes. But does it lower your lifetime taxes? If average and marginal tax rates were independent of income and didn't change through time, the answer would be an unambiguous yes. The reduction in current taxes would exceed the increase in future taxes when measured in present value. But tax rates may be higher when retirement account withdrawals occur, either because one moves into higher marginal federal and state tax brackets or because the government raises tax rates. In addition, reducing tax brackets when young, at the price of higher tax brackets when old, may reduce the value of mortgage deductions. Finally, and very importantly, shifting taxable income from youth to old age can substantially increase the share of Social Security benefits subject to federal income taxation. This paper uses ESPlanner, a detailed life-cycle personal financial planning model to study the lifetime tax advantage to stylized young couples of participating in a 401(k) plan. Assuming a percent real return on assets, we find that low- and moderate-income households actually raise their lifetime taxes and lower their lifetime expenditures by saving in a 401(k) plan. In the case of a couple with $50,000 in annual earnings, partaking fully in the typical 401(k) plan raises lifetime tax payments by 1.1 percent and lowers lifetime expenditures by 0.4 percent. The lifetime tax hike is 6.4 percent and the lifetime spending reduction is 1.7 percent for such households if they receive an 8 percent real rate of return. These figures rise to 7.3 percent and 2.3 percent, respectively, if taxes are increased by 20 percent when the couple retires. These findings are driven, in large part, by the additional Social Security benefit taxation induced by 401(k) withdrawals. The picture is quite different for high-income young couples with so much income that 401(k) participation cannot a) lower and then raise their marginal income tax rates or b) raise the share of their Social Security benefits that is taxable. For such couples 401(k) participation means major lifetime tax savings. At a 6 percent real return, a couple earning at the rate of$300,000 per year would enjoy a 6.8 percent lifetime tax break, which translates into a 3.9 percent increase in lifetime spending. These couples' continue to enjoy a large lifetime subsidy even if tax rates are raised by as much as a fifth when they retire. In addition to demonstrating the regressivity of the fe

Does participating in a 401(k) raise your lifetime taxes?

Contributing to 401(k)-type plans lowers current taxes, but does it lower lifetime taxes? If tax rates were independent of income and remained constant through time, the answer would be an unambiguous “yes.” But tax rates may be higher when retirement account withdrawals occur, either because one moves into higher marginal tax brackets or because the government raises tax rates. Moreover, reducing tax brackets when young in exchange for higher tax brackets when old renders mortgage deductions less valuable. Most importantly, shifting taxable income from youth to old age can substantially increase the share of Social Security benefits subject to federal income taxation. This paper studies the lifetime tax advantage gained from participating in 401(k) plans for stylized households. It finds that participation may increase lifetime taxes and reduce lifetime spending for low- and moderate-income households. In contrast, high-income households stand to derive significant lifetime spending gains from participating.Income tax