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NBER Summer Institute MEFM and EFG meetings, Northwestern, Princeton, Royal We define secular stagnation as the combination of interest rate close to zero, inflation .. In general, this relationship will depend on how changes in. Reflections on the new 'Secular Stagnation hypothesis' I conclude by discussing the relationship between the secular stagnation and hysteresis, global . eutrophic lakes during summer stratifica- .. was also used for redox potential measurc- .. studying relationship . of the stagnant hypolimnion is involved.
The unique properties of water molecules make ice less dense than water, so it floats on the top of the lake, allowing fish and other life to remain alive below. Ice can become so thick that little light penetrates to the water below.
Connections between summer air pollution and stagnation
Photosynthesis, already slowed by the cold temperatures, ceases to take place altogether in the dark. The ice also separates the lake water from the atmosphere so that no direct diffusion of oxygen can occur. Although fish and other organisms need very little oxygen when water temperatures are so cold, oxygen may entirely deplete, resulting in a winter fish kill. These fish kills can be prevented by keeping a hole open in the ice, which is easily accomplished by moving the water with a small aeration system.
Aeration systems may also be used to prevent ice around docks and other structures in winter. Spring As temperatures increase and melt winter ice, lakes in spring experience warming at the surface that leads to stratification, or temperature layering.
Whole lake mixing usually occurs in spring just after ice melts, but the difference in temperature between the surface and the bottom soon prevents mixing of the two layers, especially in lakes deeper than 5 or 6 feet. Frequent spring storms bring not only water to the lake, but an influx of nutrients from the landscape.
The most important policy decisions affecting wage growth over the next few years will be made by the Federal Reserve Board about when, and to what degree, to raise interest rates in an effort to slow the recovery. It is critically important that monetary policy seek to restore full employment that brings unemployment down in all communities and facilitates inflation-adjusted wage growth that matches or even exceeds for a time productivity growth.
Declining union density Research shows that unionization does not harm economic efficiency but does lead to higher wages, and does more to lift wages of low- and middle-wage workers than of high-wage workers. Collective bargaining also leads to a larger share of corporate income going to wages rather than profits; the fact that corporate profits are at historic highs is a reflection, in part, of the current weakness of collective bargaining and the heightened power of corporate owners and managers.
The decline of unions can explain about a third of the entire growth of wage inequality among men and around a fifth of the growth among women from to Other labor market policies and business practices A range of changes in what we call labor market policies and business practices have weakened wage growth in recent decades.
One of the most visible and best-documented of these changes is the lowering of the inflation-adjusted value of the federal minimum wage, a significant determinant of the distribution of U. The minimum wage, in inflation-adjusted terms, is currently more than 25 percent below its peak indespite a low-wage workforce that is much older and more educated.
Stronger and modernized labor standards e. The unleashing of the top 1 percent, particularly finance and CEOs Why have salaries of those in the top 1 percent increased so much faster than those of other high-wage earners say, those in the top 10 percentlet alone those of the middle class? There are two key reasons: Therefore, one necessary strategy to restore broad-based wage growth is to curtail the excessive wage growth at the top.
One driver of these wage trends has been financial deregulation, which has affected wage growth for the vast majority in a number of ways. First, it has enabled finance professionals to claim excessive pay and bonuses by simply hiding risk that they should be managing.
The financial sector has more than doubled in size relative to the rest of the economy over the past generation, and is hugely overrepresented in the top 1 percent of wage and income earners.
Second, because wealth holders are significantly more inflation-averse than the rest of the population, the financial industry has used its political power to ensure that economic policy favors low inflation rates over low unemployment rates.
Third, the extension of financial deregulation to international capital flows has kept policymakers from addressing imbalances e.Relationship Advice and Some Alpha M. Tough Love
The tax treatment of corporate executive pay has also had a large impact on these trends in the distribution of wage and income growth. Consequently ice floats, while water at temperatures just above freezing sinks.
As most compounds change from a liquid to a solid, the molecules become more tightly packed and consequently the compound is denser as a solid than as a liquid. Because of this density-temperature relationship, many lakes in temperate climates tend to stratify, that is, they separate into distinct layers. As the weather warms, the ice melts. The surface water heats up and therefore it decreases in density.
When the temperature density of the surface water equals the bottom water, very little wind energy is needed to mix the lake completely.
This is called turnover. After this spring turnoverthe surface water continues to absorb heat and warms. As the temperature rises, the water becomes lighter than the water below.
Seasonal Changes in Ponds and Lakes | Vertex Water Features
For a while winds may still mix the lake from bottom to top, but eventually the upper water becomes too warm and too buoyant to mix completely with the denser deeper water. As Figure 3 suggests, the relatively large differences in density at higher temperatures are very effective at preventing mixing. It simply takes too much energy to mix the water any deeper. It is useful to visualize a more extreme example of density stratification.
Imagine a bottle of salad dressing containing vegetable oil and vinegar. The oil is lighter more buoyant than the vinegar which is mostly water.
When you shake it up you are supplying the energy to overcome the buoyant force, so the two fluids can be uniformly mixed together. However, if allowed to stand undisturbed, the more buoyant less dense oil will float to the top and a two-layer system will develop.
In some cases, such as happened at Ice Lake in April, andthe surface water may warm up rapidly immediately after ice-out, causing the lake to stratify thermally without completely mixing.
This prevents atmospheric oxygen from reaching the bottom waters.
- Causes of Wage Stagnation
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- Seasonal Changes in Ponds and Lakes
This can be observed for Ice Lake by comparing temperature and oxygen profiles from March 5, still frozenApril 18, the lake was completely ice-free on April 11,and April 30, Summer As summer progresses, the temperature and density differences between upper and lower water layers become more distinct.
Deep lakes generally become physically stratified into three identifiable layers, known as the epilimnionmetalimnionand hypolimnion Figure 4. The epilimnion is the upper, warm layer, and is typically well mixed. Below the epilimnion is the metalimnion or thermocline region, a layer of water in which the temperature declines rapidly with depth.
Lake Ecology -- Density Stratification
The hypolimnion is the bottom layer of colder water, isolated from the epilimnion by the metalimnion. The density change at the metalimnion acts as a physical barrier that prevents mixing of the upper and lower layers for several months during the summer. Note that although "thermocline" is a term often used synonymously with metalimnion, it is actually the plane or surface of maximum rate of decrease of temperature with respect to depth.