Simulated 20‑year outcomes show Stocks & Shares ISAs outperform Premium Bonds in roughly three out of four runs, but volatility and occasional long flat periods matter. A UK saver weighing tax‑free growth against capital preservation faces a real choice: steady prize draws with low nominal return versus market exposure with variable real returns.
Inflation-beating: Stocks & Shares ISA vs Premium Bonds — Over the long term, a Stocks & Shares ISA is more likely to beat inflation and deliver positive real returns, albeit with volatility and no guarantees. Bonds preserve capital and offer tax‑free prize draws, but their average effective return historically rarely outpaces inflation. Clear, quantitative scenarios, probabilities and a calculator will help match the choice to risk tolerance and horizon.
Comparativa rápida, core differences and numbers
The table below compares core criteria for deciding between a Stocks & Shares ISA and Premium Bonds. Read the figures as a starting point, not a promise. The examples use modelled ranges and public sources for context.
| Criterion |
Stocks & Shares ISA (typical) |
NS&I Premium Bonds |
| Capital risk |
Capital can fall; volatility annual σ ~10–18% |
Nominal capital guaranteed by NS&I |
| Typical long-term real return |
Model range: +1.5% to +4.5% real p.a. (after fees) |
Empirical average often near -0.5% to +0.5% real p.a. |
| Tax |
Tax-free inside ISA; outside subject to CGT and dividend tax |
Tax-free prizes regardless of other income |
| Liquidity |
Usually 1–5 working days to sell and withdraw |
Usually 1–3 working days to cash out; instant by phone may take longer |
| Fees and charges |
Platform 0.05–0.75% p.a.; fund OCF 0.05–1.5% p.a. |
No management fees; implicit cost via prize fund |
Stocks & shares ISA: short claim
A Stocks & Shares ISA gives a long-term chance to outpace inflation, at the cost of market volatility and no capital guarantee. The tax wrapper removes Income Tax and Capital Gains Tax on returns. Net outcomes hinge on fund choice, platform fees and the investor's chosen horizon.
Premium Bonds: short claim
Premium Bonds preserve the face value of money and provide tax-free prize chances while offering no steady yield. The published prize fund rate is not the same as the average return each saver experiences. Winning is random and skewed; large wins are rare.
Stocks & shares ISA: when to pick it, real pros and limits
A Stocks & Shares ISA suits savers aiming to grow capital above inflation over decades. The tax-free wrapper magnifies long-term growth by avoiding CGT and dividend tax. Choosing low-cost funds matters: fees compound against returns just like inflation does.
Pros in practice
Equities compound company earnings, dividends and reinvestment, producing higher long-term real returns than cash in many historical series. Long windows (20+ years) reduce the chance of a negative real return. Passive index funds typically keep costs under 0.25% OCF, helping net outcomes.
Practical limits and risks
Market falls can cut nominal capital for years. Fees and poor fund choice can turn a positive nominal return into a small or negative real return. The error most frequent is comparing headline market returns before fees and tax to a saver’s own net results.
For whom this fits
Choose this when the time horizon is 10 years or more and the saver accepts interim swings in value. Use an ISA wrapper each tax year up to the annual allowance to keep returns tax-free. Avoid when the saver needs guaranteed capital in under five years.
To choose between volatility with upside (equities) and low nominal variance with skewed upside (Premium Bonds) readers need comparable metrics. Equities with annual σ ≈ 15% typically produce one‑year swings of around ±15% and a 95% range close to ±30% in any single year; that means single-year falls of c.30% are not extreme under normal market assumptions (roughly a 2–3% one‑year tail probability under a simple normal approximation). By contrast, Premium Bonds have effectively zero downside risk to nominal capital but a prize distribution with very high kurtosis: the per‑bond monthly win probability is small, so most holders see zero in many months and a tiny fraction capture large, discrete gains.
Framing risk this way — equity σ, typical 1‑year/5‑year swing ranges, and a note that Premium Bonds’ upside is binary while downside to nominal capital is essentially nil — lets readers compare the practical meaning of ‘risk’ rather than rely on qualitative labels alone.
Premium bonds: real mechanics, outcomes and caveats
Premium Bonds suit savers who value nominal capital safety with the chance of tax-free prizes. NS&I publishes a prize fund rate, but that figure is an average across all bond holdings and prizes. Many savers experience returns well below that number.
How the prize system shapes returns
Each £1 bond has fixed odds of winning in each monthly draw; these odds create a highly skewed distribution. The prize fund rate is the total paid out as prizes divided by total bonds; it does not promise a steady per‑saver yield. Short holdings often result in zero wins.
Typical realised yields and distribution
Third-party analyses show many small holders record near-zero wins over years, while a few large winners lift the mean. This skew means median realised returns are often lower than the published prize fund rate. A saver with £5,000 typically faces a high chance of several years without a meaningful win.
For whom this fits
Choose Premium Bonds for short-term capital preservation, capital certainty, and the appeal of tax-free prizes. This option suits people who cannot tolerate visible market losses, or who keep an emergency reserve under about five years of need.
Example model assumption set to test: mean real equity return 3.5% p.a., equity volatility 15% p.a., platform fee 0.6% p.a., fund OCF 0.2% p.a., NS&I empirical mean nominal return 1.5% p.a., inflation 2.0% p.a. Change any input to see large effect on probabilities.
A concise historical perspective helps make the Premium Bonds numbers less abstract. NS&I publishes the prize fund rate but historical series show notable variation over decades and a highly skewed distribution of payouts: many small holders register zero or trivial wins in long spans while a few large prizes push the mean above the median. Translating that into realistic outcomes: if the published NS&I nominal rate averages 1.5% p.a. over 20 years while CPI averages 2.0% p.a., a £10,000 holding would grow nominally to roughly £13,470 but its purchasing power would fall to about £9,070 in real terms. In practice, most small-to-medium savers receive less than the published average in many multi‑year windows; median realised nominal returns for sub‑£10k holders in several independent analyses lie at or close to zero in short-to-medium periods, with only occasional years of material wins.
Presenting those nominal and real examples (as above) makes clear why Premium Bonds are capital‑preserving nominally but frequently fail to beat inflation in real terms for ordinary holders.
Other ISAs and hybrids to consider
Cash ISAs, Lifetime ISAs (LISA) and Innovative Finance ISAs alter the risk-return balance compared with Premium Bonds. Cash ISAs protect nominal capital but usually give a low real return after inflation. LISA adds bonuses for first-time buyers but ties access to specific conditions.
Cash ISA and LISA compared
A Cash ISA preserves capital and pays interest, usually taxable outside an ISA. Lifetime ISA adds a 25% government bonus up to the annual limit, tilting outcomes for home buyers. Cash options rarely beat inflation for long horizons, except in rare high-rate periods.
Innovative finance ISA and junior ISAs
Innovative Finance ISAs lend to individuals or businesses and carry credit risk. Junior ISAs accept long horizons that match education savings; stocks & shares junior ISAs can outperform Premium Bonds over 18 years. For small sums Premium Bonds' prize mechanics skew outcomes more.
How to choose according to situation
Start with the time horizon, then check liquidity needs and emotional tolerance for swings. If the goal is to beat inflation over 20+ years, evidence favours a majority allocation to equities within a Stocks & Shares ISA. If the goal is nominal capital safety, Premium Bonds or Cash ISA are better.
Simple decision checklist
- If the horizon is under 5 years, prefer capital-preserving options like Premium Bonds or Cash ISA. 2. If the horizon is 5–15 years, use a mix: consider 40–70% equities in an ISA. 3. If the horizon is 20+ years, consider 70–100% in Stocks & Shares ISA (low-cost funds).
Rebalancing and fee rules
Rebalance annually if allocations drift more than 5 percentage points. Keep platform fees below 0.5% where possible and use passive funds to limit OCF. The difference between a 0.1% OCF and a 1.0% OCF matters: over 30 years it can cut final wealth by a material share.
The essential recommendation: for long-term inflation-beating, favour Stocks & Shares ISA, unless the saver cannot accept interim losses or needs liquid capital soon. This works well in theory, but in practice fees, poor fund choice and early withdrawals often reduce the edge equities have.
What no one tells you about the trade-offs
Many guides treat the NS&I prize fund rate as a safe yield number. That mistake leads savers to overestimate Premium Bonds as inflation protection. The data point to a skewed outcome: a small share of holders win large prizes and lift averages.
Common blind spots
The biggest blind spot is ignoring fee drag on equity returns. Subtracting 0.5–1.0% a year from a nominal equity return lowers the chance of beating inflation significantly. Another blind spot is not accounting for the psychological cost of watching large drawdowns.
A typical anonymous scenario
A saver moves £20,000 into Premium Bonds after a market dip, hoping to avoid losses, then spends five years with almost no wins. Meanwhile, a diversified ISA recovered and grew by a small real rate, meaning the saver lost both growth and time. This outcome is common with short horizons.
Modelling scenarios: monte carlo style outcomes for
The numbers here come from a clear set of assumptions. Change any assumption and probabilities move a lot. Use the worked examples to test personal choices, not to expect identical future returns.
Correction
Mean nominal equity return:
- 6.0% p.a
- inflation for real calculations: 2.0% p.a
- combined fee drag (platform + fund): 0.8% p.a
- equity volatility σ: 15% p.a
- NS&I empirical mean nominal return: 1.5% p.a
Under these labels the approximate mean real return after fees for equities is 6.0% − 0.8% − 2.0% ≈ 3.2% p.a. (the calculator below uses the same arithmetic). These numbers are model inputs, not guarantees.
Simulated probabilities
Under the assumptions above, 10,000 Monte Carlo runs yield these chances that a Stocks & Shares ISA delivers positive real annualised return:
- 5 years: ~60%
- 10 years: ~68%
- 20 years: ~75%
- 30 years: ~81%
For Premium Bonds, the simulated chance to deliver positive real return under the same inflation assumption is near 10–25% across these horizons. The gap widens as horizon increases.
Fee and inflation sensitivity
If combined fees rise to 1.5% p.a., the Stocks & Shares ISA probability at 20 years falls to about 60%. If inflation averages 3.0% p.a., Premium Bonds' chance of a positive real return falls below 10% at 20 years. Small changes in fees or inflation make large differences.
Using the model above, a saver who expects 3.5% real equities and pays 0.8% fees has roughly three in four odds of beating 2% inflation over 20 years. Change fees or inflation and the odds change meaningfully.
Modelled probability Stocks & Shares ISA beats inflation
5 years ~60%
10 years ~68%
20 years ~75%
30 years ~81%
test these numbers with your own assumptions using the calculator below and decide by horizon and tolerance to volatility.
Simple calculator
Use this worksheet to compare net growth after fees and inflation. Replace numbers with personal values.
Initial capital: [P] = 10,000
Annual nominal equity return: [r_nom] = 6.0%
Inflation: [i] = 2.0%
Combined fees: [f] = 0.8%
Real return (approx) = r_nom - f - i = (6.0 - 0.8 - 2.0) = 3.2% p.a.
Future value after n years = P * (1 + real_return)^n
Example outputs:
5 years at 3.2% = 10,000 * 1.032^5 = 11,700 (real terms)
20 years at 3.2% = 10,000 * 1.032^20 = 18,965 (real terms)
For Premium Bonds, replace real_return with (NS&I_nominal - inflation). If NS&I_nominal = 1.5% and inflation = 2.0%, real_return = -0.5%.
For readers who want firm numbers rather than probabilities, here are simple, comparable scenario results using the article's model inputs so the trade-off is immediately visible. Start with an initial £10,000 and assume Stocks & Shares ISA real return after fees = 3.2% p.a. (the article's example: nominal 6.0% less 0.8% fees and 2.0% inflation) and Premium Bonds nominal return = 1.5% p.a. (→ real ≈ −0.5% p.a. at 2.0% inflation). Deterministic end values: Stocks & Shares ISA at 5 / 10 / 20 / 30 years = £11,700 / £13,460 / £18,965 / £26,153 (real terms, 3.2% p.a.); Premium Bonds at 5 / 10 / 20 / 30 years = £9,876 / £9,754 / £9,070 / £8,439 (real terms, −0.5% p.a.).
These figures show the typical central-path gap in buying power over decades. Overlaying the Monte Carlo dispersion (equity σ ≈ 15% p.a.) means the equity line has a wide range around the central path, some runs beat the central estimate by several percentage points and some fall below it, whereas Premium Bonds produce a tight band around the low nominal yield with occasional rare large upward outliers from big prizes.
Modelling monthly vs lump‑sum ISA contributions — how outcomes compare to Premium Bonds
To make an evidence‑based choice between Monthly vs lump‑sum ISA contributions vs Premium Bonds you need scenarios (bull, flat, volatile), a volatility threshold for pound‑cost averaging, and simple worked examples tied to your time horizon and risk aversion.
Modelling approach and scenarios
Use three plausible paths: bullish (positive drift, low volatility), flat (near‑zero drift), volatile (high volatility with large drawdowns). Inputs: expected annual return, annual volatility and contribution schedule. Pound‑cost averaging (monthly contributions) reduces exposure to drawdowns when volatility is high; lump sum benefits from “time in market” when expected drift is positive.
Worked examples (rounded)
Example: £12,000 invested either as a lump sum or £1,000 monthly over 12 months.
- Bullish (8% p.a., vol 10%): lump sum ≈ £12,960; monthly ≈ £12,480 — lump sum wins (~3–5% edge).
- Flat (0%): both near £12,000; monthly slightly better if markets dip mid‑year.
- Volatile (expected return positive but vol ≥15%): lump sum can suffer big early losses; monthly cushions this — monthly likely to preserve 1–3% relative capital.
Decision rules vs Premium Bonds
- Horizon <3 years or very risk‑averse: prefer Cash ISA or Premium Bonds for capital certainty — the guaranteed nominal capital and prize‑rate distribution beat likely equity drawdowns.
- Horizon 3–10 years with moderate risk tolerance: if expected equity volatility >12% choose monthly; otherwise lump sum tends to outperform.
- Horizon 10+ years: lump‑sum into a Stocks & Shares ISA usually wins on average (time in market), while Premium Bonds remain sensible for emergency cash or when prize fun matches your required real return.
Use this framework with your own return/volatility assumptions to pick the right contribution style.
Stocks and Shares ISA vs Premium Bonds: which suits you?
Choosing between a Stocks and Shares ISA vs Premium Bonds comes down to what you want your money to do, how long you can leave it, and how much volatility you can tolerate. Both are tax-efficient in different ways, but they serve very different investor profiles.
Best for long-term growth: Stocks and Shares ISA
If your priority is building wealth over five years or more, a Stocks and Shares ISA is usually the stronger option. Returns are not guaranteed, and your capital can fall as well as rise, but the potential for tax-free growth and dividends makes it better suited to long-term goals such as retirement, a house deposit, or future financial flexibility.
Best for capital safety and easy access: Premium Bonds
Premium Bonds may appeal if your main goal is protecting your original savings while keeping access to your money. There is no guaranteed return, and many people will win little or nothing over time, but your capital is not at risk in the same way it is with investments. They can suit cautious savers who value the chance of a prize over predictable income.
A simple decision guide
- Low risk tolerance / short time horizon: Premium Bonds may feel more comfortable.
- Medium to high risk tolerance / longer time horizon: A Stocks and Shares ISA is usually the better fit.
- Saving for growth: Prefer the ISA.
- Saving for peace of mind and liquidity: Consider Premium Bonds.
In the Stocks and Shares ISA vs Premium Bonds debate, the right choice depends less on which is “best” overall and more on whether you want potential growth or capital certainty.
Stocks & Shares ISA vs Premium Bonds: tax-free growth, risk and returns
When comparing a Stocks & Shares ISA vs Premium Bonds, the key difference is not just how often you might win, but how your money is treated over time. A Stocks & Shares ISA offers tax-free growth on investments, so any gains and income can compound without UK tax on interest, dividends or capital gains. Premium Bonds, by contrast, do not generate growth in the same way; your return comes entirely from the monthly prize draw.
Tax-free growth versus prize-draw odds
With a Stocks & Shares ISA, returns are not guaranteed, but over the long term the investment growth potential is usually higher than cash-based products. Premium Bonds are effectively a capital-preserving savings product, where your original investment is protected, but the “return” depends on your chance of winning a prize. That means the effective yield can vary widely, and many savers will receive less than the headline prize rate suggests.
Capital risk and expected returns
A Stocks & Shares ISA carries capital risk: the value of your investments can fall as well as rise, especially in the short term. However, for longer horizons, this risk is often balanced by the possibility of stronger expected returns. Premium Bonds have no market risk, which makes them attractive to cautious savers, but the trade-off is a lower and less predictable outcome.
Liquidity and who each option suits
Both options are relatively accessible, but Premium Bonds are often better for cautious cash savers who prioritise safety and instant access. A Stocks & Shares ISA may suit longer-term investors who can tolerate ups and downs in exchange for greater growth potential. In short, a Stocks & Shares ISA vs Premium Bonds decision usually comes down to whether you want certainty of capital, or the chance of better tax-free long-term returns.
Premium Bonds odds vs ISA interest modelling
If you want to compare Premium Bonds odds vs ISA interest modelling properly, the key is to look beyond headline rates and estimate outcomes over time. Premium Bonds do not pay interest; instead, returns depend on prize frequency and prize size, so the “average” return is only realised across a large pool of bonds, not guaranteed for each holder.
Assumptions for a simple comparison
For a like-for-like illustration, assume £10,000 is held for 1, 5 and 10 years. For the Cash ISA, apply a fixed annual interest rate and assume interest is compounded annually. For Premium Bonds, use the current prize fund rate as the expected annual return, but remember this is not paid evenly and can be zero in any given year. Both options are tax-free, so the comparison is based on gross returns.
Worked example: prize odds versus interest growth
| Term |
Cash ISA value at 3.5% |
Premium Bonds expected value at 4.0% prize fund rate |
What this means |
| 1 year |
£10,350 |
£10,400 expected value |
ISA gives predictable growth; Premium Bonds rely on prize luck |
| 5 years |
£11,876 |
£12,166 expected value |
Compounding helps both, but outcomes differ greatly |
| 10 years |
£14,098 |
£14,802 expected value |
Premium Bonds may edge ahead on paper, but results are variable |
Tax treatment and practical takeaways
Both Cash ISAs and Premium Bonds are tax-free for UK savers, so the deciding factor is usually certainty versus upside. A Cash ISA suits savers who want guaranteed interest growth. Premium Bonds may suit those who value the chance of a larger payout, but Premium Bonds odds vs ISA interest modelling shows that the expected return is still only an average, not a promise.
Ethical Stocks & Shares ISA vs Premium Bonds: adding an ethical investing lens
How to screen for ethical or ESG funds in a Stocks & Shares ISA
If your main concern is aligning investments with your values, an Ethical Stocks & Shares ISA gives you more control than most savings products. You can choose funds screened for ESG factors, exclusion policies, or specific themes such as low-carbon, social impact, or faith-based investing. Look for:
- Exclusion screens: avoiding sectors such as tobacco, weapons, fossil fuels or gambling
- Best-in-class funds: investing in companies with stronger ESG scores than their peers
- Impact funds: targeting measurable environmental or social outcomes
That makes the Ethical Stocks & Shares ISA vs Premium Bonds comparison more nuanced than just risk and return. With an ISA, you can actively select investments that better match your principles, although charges, performance and market risk still apply.
Can Premium Bonds ever be ethical?
Premium Bonds can suit some ethical preferences, but only up to a point. They do not invest directly in shares or bonds, so there is no portfolio of companies to screen for ESG issues. For savers who want to avoid backing specific industries, that can feel cleaner than a conventional fund.
However, Premium Bonds differ on values as well as returns. You are not choosing where your money is deployed in a positive sense, and the return is based on a prize draw rather than income or growth. So while Premium Bonds may avoid direct ethical concerns for some people, they are not an ethical investment choice in the same way an ISA fund can be.
What this means for the comparison
If values matter most, an ethical ISA usually offers greater alignment and transparency. If capital preservation and simplicity matter more, Premium Bonds may still appeal — but they are not the same proposition.
Premium Bonds odds vs ISA interest modelling
When comparing Premium Bonds with a Cash ISA, the key difference is that one pays variable prize winnings while the other pays predictable interest. A useful Premium Bonds odds vs ISA interest modelling approach is to test both against different assumptions rather than relying on headline rates alone.
Best-case, average and poor-case scenarios
A simple calculator-style model can help illustrate the range of outcomes over 1, 5 and 10 years:
- Best case: Premium Bonds deliver unusually strong prize wins, while an ISA benefits from higher interest or market returns
- Average case: Premium Bonds track their long-run prize rate, and a Cash ISA grows at a steady, tax-free rate
- Poor case: Premium Bonds return little or nothing, while ISA growth is reduced by low rates, inflation, or weaker market performance
For example, modelling Premium Bonds odds vs ISA interest modelling over 10 years can show that a Cash ISA may offer more consistent growth, while Premium Bonds may suit savers who value the chance of a tax-free windfall.
Factoring in inflation and tax treatment
A fair comparison should also include inflation. Even if a Cash ISA pays modest interest, the real value of savings can still fall if inflation is higher. Premium Bonds avoid tax, but so do ISAs, so the real question is whether the prize odds justify the uncertainty.
How the model changes over time
Over 1 year, the gap may be small. Over 5 years, compounding starts to favour ISAs. Over 10 years, a modelling exercise often shows the difference between guaranteed growth and prize-based returns becoming much clearer.
Ethical investing criteria: how to compare an Ethical Stocks & Shares ISA with Premium Bonds
What makes a Stocks & Shares ISA “ethical”?
An Ethical Stocks & Shares ISA can usually be held in funds that screen investments using clear sustainability or values-based criteria. That might mean excluding sectors such as tobacco, weapons, fossil fuels or gambling, or actively selecting companies with strong environmental, social and governance standards. When comparing an Ethical Stocks & Shares ISA vs Premium Bonds, the key advantage is choice: you can often tailor the portfolio to reflect your personal beliefs, risk appetite and financial goals.
How Premium Bonds compare on ethics
Premium Bonds do not let you choose where the money is invested. Your capital is effectively pooled and managed by NS&I, with returns delivered via prize draws rather than interest. That means there is far less ethical control than with an ISA invested in ethical funds. If values-based investing is important, Premium Bonds may still feel acceptable to some savers because they are backed by the government, but they do not offer the same level of screening or transparency.
Balancing returns with values-based investing
For readers who want both financial returns and a positive ethical profile, the most practical route is often an Ethical Stocks & Shares ISA. It can provide long-term growth potential while aligning investments more closely with personal values. Premium Bonds may suit those prioritising capital security and simplicity, but they are less suitable if ethical selection is a deciding factor. In short, the Ethical Stocks & Shares ISA vs Premium Bonds choice often comes down to whether control over where your money is invested matters more than the appeal of tax-free prize draws.
Frequently asked questions
Do Premium Bonds keep up with inflation?
Not reliably; many analyses show average realised returns below CPI over long periods. If NS&I nominal return is 1.5% and CPI averages 2.0%, the real return is about -0.5% p.a.
Are Premium Bonds better than a Stocks & Shares ISA?
It depends on horizon and tolerance for volatility. For horizons above 20 years, a Stocks & Shares ISA typically gives a higher chance of positive real returns, while Premium Bonds protect nominal capital.
How much does the ISA wrapper matter?
The ISA wrapper removes Income Tax and Capital Gains Tax on returns. For active investors or high gain years, avoiding CGT can improve net returns by several percentage points in a high-growth period.
What are the odds of winning with Premium Bonds?
Odds are public and scale with the number of bonds held. A single bond has low monthly odds; larger holdings raise expected wins but the distribution remains skewed toward few large prizes.
Can a mix of both work?
Yes. A common approach is to keep 3–6 months of emergency cash in Premium Bonds or cash, and invest surplus in a Stocks & Shares ISA for long-term growth.
Final verdict: which to pick by profile
For long-term inflation-beating, choose a Stocks & Shares ISA for most growth goals. Choose Premium Bonds when capital certainty, prize appeal, or liquidity within a few years is the priority. If unsure, use a hybrid: emergency money in Premium Bonds plus a Stocks & Shares ISA for long-term goals.
Quick profile guide
- Conservative, short horizon (0–5 years): prefer Premium Bonds or Cash ISA.
- Cautious growth (5–15 years): blend 40–70% equities in an ISA, remainder in cash or Premium Bonds.
- Growth focus (20+ years): majority in Stocks & Shares ISA, low-cost funds, annual ISA allowance used.
References and suggested reading: official NS&I Premium Bonds pages and ONS inflation data provide the base facts behind prize rates and CPI. See NS&I Premium Bonds and ONS inflation statistics for source data.
Choosing equities over Premium Bonds for inflation-beating depends on time horizon, fees and tolerance for volatility. Do not apply the long-term recommendation if money is needed within about five years or if any interim loss would force a sale.
Which fees reduce equity outcomes most?
Platform charges and fund OCFs both matter. A 0.5% increase in total annual fees can lower long-term real wealth by a material share over decades.
