1. Introduction
Increases in interest rates have become a major issue for stakeholders in global real estate investment markets. In the wake of the COVID-19 crisis, the accumulation of government debt across global capital markets has contributed to a sustained inflationary environment since late 2021 [
1,
2,
3]. Since the initial rate increases, major central banks worldwide have adopted a more restrictive monetary stance, implementing substantial hikes in policy rates. The Federal Reserve raised rates by 525 basis points, followed by the Bank of England (500 basis points), the European Central Bank (450 basis points), the Bank of Canada (475 basis points), and the Reserve Bank of Australia (425 basis points) [
4]. Office real estate is a key sector within the built environment and buildings industry, and it has been substantially affected by the recent global interest rate hike cycle. This tightening cycle placed upward pressure on capitalization and discount rates, which in turn exerted downward pressure on office real estate asset values [
5,
6,
7]. For example, between March 2022 and June 2024, office real estate asset values declined across the US (−29.2%), UK (−19.5%), Europe (−14.1%), Canada (−28.2%), and Australia (−26.8%) [
8]. In 2024, institutional investors were under allocated to real estate, with allocations below target in the Americas (50 bps), EMEA (10 bps), and Asia-Pacific (160 bps) [
3].
While a highly volatile investment context for commercial real estate investors has persisted due to major geopolitical uncertainties (e.g., the Russia-Ukraine war, Middle East conflicts, trade disputes, etc.), the post-pandemic inflationary climate stabilized by late 2024 [
3]. In response, global key central banks implemented interest rate cuts. As global key central banks’ tightening monetary policy has turned a corner, office real estate quarterly returns moved into a positive territory in September 2024, including the US (1.7%), UK (0.5%), Germany (0.1%), Canada (1.6%), and Australia (4.3%) [
8]. The ANREV 2025 industry survey shows that more than one-third of global institutional investors plan to increase real estate allocations in the next two years [
9]. The year 2025 is expected to open a window for institutional investors to tactically rebalance their real estate allocations [
3]. Overall, these trends highlight the substantial impacts of interest rates on office real estate investment, particularly for asset value growth and capital returns [
2]. The ANREV/INREV/PREA 2025 industry survey highlights interest rate policy continuing as the most critical investment concern for global institutional real estate investors in 2025 [
9].
In the real estate investment context, the IPE 2024 industry report shows prominent global real estate investors include Allianz (Germany), Government Investment Corporation (GIC, Singapore), China Investment Corporation (CIC, China), Abu Dhabi Investment Authority (ADIA, the United Arab Emirates), and Government Pension Fund Global (GPFN, Norway), as exhibited in
Table 1. The INREV 2025 industry survey reports that non-listed real estate investment has become a significant investment conduit for institutional real estate investors, including pension funds (43% of total global non-listed real estate investment by capital in 2024), insurance companies (19%), sovereign wealth funds (7%), and government institutions (5%), to achieve their real estate allocations, accounting for USD 3.7 trillion in 2024 [
10]. The Nuveen 2025 industry report documents that these institutional real estate investors typically allocate capital in real estate at rates of 10.5% in the Americas, 10.3% in EMEA, and 9.3% in the Asia-Pacific [
3]. A variety of investment vehicles, such as non-listed real estate funds, separate accounts, joint ventures, club deals, and funds of funds, further support non-listed real estate investment. In the non-listed real estate investment space, office real estate is listed as one of the main sector exposures for global non-listed real estate investment [
9,
11,
12,
13].
Table 2 shows prominent non-listed office real estate investment managers across the regions in the IPE 2024 industry report. American-focused major office real estate investment managers include Brookfield Asset Management (USD 46.9 billion in 2024), Hines (USD 32.7 billion), Nuveen Real Estate (USD 23.4 billion), JP Morgan Asset Management (USD 19.2 billion), and New York Life Real Estate Investors (USD 16.3 billion). European-focused major office real estate investment managers are named Deka Immobilien Investment, PIMCO Real Estate, Swiss Life Asset Management, AXA Investment Managers, and DWS Asset Management. Asia-Pacific-focused major office real estate investment managers are ESR Group (USD 17.3 billion), Charter Hall (USD 15.1 billion), Mapletree Investments (USD 11.8 billion), CapitaLand Investment (USD 11.4 billion), and Gaw Capital Partners (USD 10.8 billion).
Despite significant investments from institutional investors in real estate, the limited availability of robust data for non-listed real estate has led to a scarcity of studies discussing the investment performance of composite non-listed real estate [
15,
16,
17]. Limited studies focused on investment performance comparisons (e.g., annual total returns) between non-listed office real estate and other non-listed real estate subsectors at a single market/region level [
13,
18,
19]. However, prior research on non-listed real estate has yet to be devoted to investment opportunities and tactical portfolio construction rebalancing strategies for non-listed office real estate across global markets and various interest rate cycles. This is despite the acknowledgment of differential real estate investment performance across global markets [
20,
21], as well as interest rate risk being identified as a crucial factor in real estate investment [
22,
23,
24]. Hence, it is necessary to offer an empirical analysis of the investment performance and portfolio construction strategy for non-listed office real estate across global markets and varying interest rate cycles, using the mean-downside risk portfolio framework to address the highly turbulent investment risk associated with interest rate cycles.
This study extends existing literature to examine the impacts of interest rate cycles on portfolio construction strategies for non-listed office real estate across the US, UK, Germany, Canada, and Australia, given that these five major markets accounted for more than 45% of the global commercial real estate markets by market capitalization in 2024 [
25]. Therefore, three research questions (RQ) have been formulated to satisfy the aims of this paper, as follows:
RQ 1. How does global non-listed office real estate performance vary across different interest rate cycles?
RQ 2. What role does global non-listed office real estate play in multi-asset portfolio construction when accounting for shifts in interest rate regimes?
RQ 3. How do allocation strategies within global non-listed office real estate portfolios adjust across interest rate cycles, particularly during the most recent tightening phase after 2022?
This study makes a significant contribution to the literature in several ways. First, it provides a comprehensive and evidence-based analysis of the investment characteristics and portfolio construction strategies for non-listed office real estate across the US, UK, Germany, Canada, and Australia under different interest rate cycles. Unlike previous research (e.g., [
13,
18,
19]), which primarily examined return performance over limited timeframes, this study extends these studies by systematically assessing how non-listed office real estate behaves and contributes to portfolio strategies across multiple interest rate regimes. Second, this paper explicitly incorporates the dynamics of the most recent tightening cycle post-2022, which has not yet been captured in existing studies. This allows for timely insights into how rapidly rising interest rates influence the risk–return profiles and portfolio roles of non-listed office real estate. Third, by applying portfolio theory in both multi-asset and global non-listed office real estate portfolios, this study extends the literature beyond simple performance measurement. It evaluates the strategic and tactical implications of allocating to non-listed office real estate under varying macro-financial conditions, thereby offering a richer understanding of its role for institutional real estate investors. Lastly, this study employs a downside risk framework, rather than relying solely on mean–variance analysis, to evaluate the investment performance of the non-listed office funds. This approach is particularly relevant in the current environment of heightened macroeconomic and financial uncertainty, as it provides a more realistic assessment of risk exposure and hedging potential. Essentially, this paper offers both theoretical and practical insights into investment implications. The following section reviews relevant literature to establish the conceptual foundations for this study.
7. Robustness Checks
To validate the stability and reliability of the baseline findings, a series of robustness checks was conducted across multiple dimensions. These include sensitivity analyses of (1) the de-smoothing parameters applied to non-listed real estate returns, (2) alternative specifications of the minimum acceptable return (MAR), (3) different portfolio allocation constraints for non-listed real estate, (4) the incremental contribution of non-listed office real estate to benchmark stock–bond portfolios, (5) the impacts of COVID-19 as an alternative global phase intersection, and (6) country-specific interest rate turning points for major markets (UK, Eurozone, Canada, and Australia). The robustness check results were not reported, for brevity, but are available upon request from the authors.
7.1. De-Smoothing Parameters Sensitivity Analysis
Given that smoothed real estate returns can lead to an underestimation of actual real estate risk [
53,
54], the non-listed real estate returns in this study were de-smoothed using [
56] de-smoothing approach with a parameter of 0.5. Nevertheless, the robustness of the baseline results should be further examined under alternative parameter specifications. To strengthen the robustness of the baseline results, this study incorporated sensitivity analyses by using alternative de-smoothing parameters, α = 0.2, α = 0.3, and α = 0.7. As echoed by [
72], building on [
73] and [
74], in global private real estate markets, a one-year lag (equivalent to four quarters) implies a smoothing parameter of α, with an approximate value of 0.2. In addition, the sensitivity of the parameters is also assessed, using α = 0.3 and α = 0.7. These results are generally consistent with the baseline results, where non-listed office real estate played a more significant role in multi-asset portfolios across the five markets in interest rate hike cycles than in interest rate cut cycles. These imply the baseline results are robust to variations in the de-smoothing parameters.
7.2. Minimum Acceptable Return (MAR) Sensitivity Analysis
To assess the reliability of the baseline estimates, this study also deployed an alternative MAR value = 0 over the study sub-periods. The results are fairly robust and did not alter the conclusion. These indicate that the baseline results are robust to variations in the MAR values.
7.3. Non-Listed Real Estate Fixed at 10%
In addition to the real estate portfolio allocation capped at 10%, this study examined the alternative scenario of the real estate portfolio allocation fixed at 10%. The results are fairly in line with the baseline results. This implies the alternative real estate portfolio allocation scenario did not alter the conclusion of this study.
Figure 6.
Global non-listed office real estate asset allocation diagram across interest rate cycles. Note: The US dollars; The portfolio allocation summary table was not reported for brevity but is available upon request from the authors.
Figure 6.
Global non-listed office real estate asset allocation diagram across interest rate cycles. Note: The US dollars; The portfolio allocation summary table was not reported for brevity but is available upon request from the authors.
7.4. Addition of Non-Listed Office Real Estate to the Benchmark Portfolio
This study estimated a portfolio alpha for the addition of non-listed office real estate to the market benchmark portfolio, which consists of stocks and bonds only, reflecting the classical 60-40 portfolio allocation strategy for institutional investors. The results showed that the addition of non-listed office real estate significantly outperformed the market benchmark portfolios across the five markets in both interest rate cut and hike cycles. However, the addition of non-listed office real estate marked a slight difference from the market benchmark portfolio across the five jurisdictions in the interest rate hike cycle after the COVID recession stimulus package. These highlight the added value of non-listed office real estate in global multi-asset portfolios for institutional real estate investors.
7.5. Hybrid Working Trends and Alternative Global Intersection Phases—The Impacts of COVID
As echoed by [
67,
68], the hybrid working trend, as a structural change in the global office space, has been observed in the post-COVID context. This study measured the impacts of COVID as a structural change in the global office space, as well as the alternative global phase, which is the intersection/union of local phases. The analysis estimated model parameters on the pre-COVID period (from December 2012–December 2019), evaluated performance during COVID (from March 2020-December 2020), and post-COVID (from March 2021–June 2024). The pre-COVID period broadly aligned with the empirically selected interest rate hike cycle (from December 2015–March 2019), while the COVID period is broadly consistent with the empirically selected interest rate cut cycle (from June 2019–December 2021). Also, the post-COVID period is broadly in line with the empirically selected interest rate hike cycle (from March 2022–June 2024). The results broadly aligned with the main baseline results, where non-listed office real estate played a more significant role in the multi-asset portfolios in interest rate hike cycles than in interest rate cut cycles. In addition, this study examined the out-of-sample period—the recent interest rate cut cycle between September 2024 and December 2024. The results aligned with the baseline results of this study.
7.6. Country-Specific Interest Rate Turning Points in the UK, Europe, Canada, and Australia
To ensure that the results are not sensitive to the empirical choice of global interest rate cycle dating, this study performed robustness checks using country-specific interest rate turning points for the UK, the Eurozone, Canada, and Australia. In the UK, interest rate cycles include June 2008–September 2017 (interest rate cut), December 2017-December 2019 (interest rate hike), March 2020-September 2021 (interest rate cut), and December 2021-June 2024 (interest rate hike). In Germany, interest rate cycles include December 2012–June 2022 (interest rate cut), September 2022-June 2024 (interest rate hike). In Canada, interest rate cycles include June 2008-June 2017 (interest rate cut), September 2017-December 2019 (interest rate hike), March 2020-December 2021 (interest rate cut), and March 2022–June 2024 (interest rate hike). In Australia, interest rate cycles include June 2008-March 2022 (interest rate cut) and June 2022-June 2024 (interest rate hike). While these countries exhibit broadly similar patterns to the US, defining cycles based on local policy rates produces results consistent with our main baseline findings, where non-listed office real estate played a more significant role in the multi-asset portfolios across the UK, Germany, Canada, and Australia in interest rate hike cycles than in interest rate cut cycles.
Collectively, these checks confirm that the main conclusions—particularly the role of non-listed office real estate as a more significant contributor to multi-asset portfolios during interest rate hike cycles—remain consistent across alternative assumptions and specifications.
8. Conclusions
This paper assessed portfolio allocations to non-listed office real estate across the US, UK, Germany, Canada, and Australia over four interest rate cycles, addressing three research questions (RQ1, RQ2, and RQ3). It utilized the mean-downside risk portfolio analysis to account for the highly turbulent investment environments associated with these cycles. In particular, the US Federal Reserve’s rate cut phases closely coincided with periods of global and US structural and cyclical economic stress, such as the Global Financial Crisis (GFC) and the COVID recession. Two mean-downside risk portfolio analyses were performed. The multi-asset portfolio analysis assessed the added-value role of non-listed office real estate within multi-asset portfolios composed of stocks and bonds, with real estate allocations capped at 10%, reflecting the practical allocation in institutional investors’ multi-asset portfolios. Also, the real estate portfolio analysis was designed to assist institutional real estate investors in tactically reallocating non-listed office real estate portfolios across global markets and various interest rate cycles.
By conducting these analyses, this paper contributes to extending existing research (e.g., [
13,
18,
19]) on non-listed office real estate investment in numerous dimensions: (1) this study provides comprehensive insights into tactical investment strategies for non-listed office real estate across global markets and varying interest rate cycles, and (2) this paper offers empirically tactical portfolio allocation strategies for non-listed office real estate in institutional investors’ multi-asset portfolios across global markets and varying interest rate cycles. The portfolio construction analysis is designed by an actual real estate allocation in institutional investors’ multi-asset portfolios; (3) this study delivers empirically tactical portfolio allocation strategies for global non-listed office real estate portfolios in market selections and geographical diversifications across various interest rate cycles, and (4) this research deploys the mean-downside risk portfolio analysis to address the volatile investment context in interest rate cycles.
Several key findings have been identified. Firstly, the analysis results provide critical empirical validation for the added-value role of non-listed office real estate in institutional investors’ multi-asset portfolios across the UK, Germany, Canada, and Australia during the interest rate hike cycle preceding the COVID recession. This is generally attributed to the superior risk-adjusted returns of non-listed office real estate compared to other asset classes in each of the four markets, driven by their high returns, low volatility profile, and desirable portfolio diversification benefits from an investment perspective. These are important for institutional real estate investors with significant investment exposure to stocks and bonds.
Secondly, after the COVID recession, non-listed office real estate did not contribute to the multi-asset portfolios across the US, UK, Germany, and Canada over the interest rate cut and interest rate hike cycles. This can be attributed to the structural changes in the global office space markets driven by hybrid working arrangements since the COVID-19 pandemic [
3,
67] and the rapid US rate hike cycle since March 2022, with a 500-basis-point increase in 10 quarters [
71]. The rapid rate hikes resulted in severe devaluations across global office markets since March 2022 [
2,
8]. However, Australian non-listed office real estate was the exception as it exhibited the added-value role in the multi-asset portfolio during the interest rate hike cycle from March 2022 to June 2024, albeit other non-listed real estate subsectors had no role. This may be attributed to Australian non-listed office real estate, which exhibits strong diversification effectiveness compared to stocks and bonds during this period and remains immune to interest rate changes, as empirically corroborated by the findings of [
23] on listed office real estate. It is noteworthy that the US non-listed office real estate sector experienced non-existent allocations during the interest rate hike and cut cycles preceding or following the COVID recession.
Thirdly, the results show that capped portfolio allocations to non-listed office real estate averaged 0.7% in the UK, 0.4% in Germany, 0.7% in Canada, and 9.1% in Australia over the interest rate hike cycle preceding the COVID recession, but declined to zero during the interest rate cut phases. Over the interest rate hike phase after the COVID recession, Australian non-listed office real estate averaged 0.8% in constrained multi-asset portfolios for institutional investors. Lastly, the US non-listed real estate dominated global non-listed office real estate portfolios during both interest rate cut cycles (average allocation: 64.5%) and interest rate hike cycles (64.3%). This aligns with [
23,
24], who empirically tested the US-listed office real estate immune to domestic interest rates. In the global non-listed office real estate portfolios, the average allocation to Australia was 24.2% during interest rate hike cycles, while the average allocation to Germany was 32.0% during interest rate cut cycles.
This research formulates numerous practical real estate investment and diversification implications concerning non-listed office real estate investment strategies for institutional real estate investors and investment managers. The COVID-19 pandemic stimulus package, inflationary pressures, and high interest rates mark a turning point in tactical real estate investment strategies across various interest rate cycles, emphasizing the need for improving portfolio investment performance, which has been the primary objective for institutional real estate investors and investment managers. This implies that the search for tactical and attractive investment routes and strategies to enhance portfolio returns has become one of the key focuses, given the persistently challenging investment contexts in recent years. Since this research focuses on portfolio allocations to non-listed office real estate across various markets and interest rate cycles, institutional real estate investors with significant exposure to office real estate, such as pension funds, insurance companies, sovereign wealth funds, and government institutions, can benefit from these findings.
Overall, this research provides institutional real estate investors with tactical and valuable insights into the investment characteristics of non-listed office real estate in multi-asset portfolios across the US, UK, Germany, Canada, and Australia over various interest rate cycles. Institutional investors should acknowledge the differential investment performance of non-listed office real estate in each of the five markets. This research provides valuable practical insights for institutional real estate investors and investment managers with an understanding of the impact of monetary policy on market characteristics, in addition to the effectiveness of global office real estate portfolios via non-listed real estate investment conduits, to deploy rebalancing strategies based on market selections and geographical diversifications across various interest rate cycles. These are particularly relevant for institutional real estate investors and investment managers tactically rebalancing real estate portfolio allocations when interest rate cycles reach a turning point, as echoed by [
2,
3,
24]. Lastly, this research highlights the role of non-listed office real estate as an effective investment vehicle for institutional real estate investors and investment managers to capitalize on the distinctive features, quality, and performance across varying markets and interest rate cycles.
While this study provides institutional real estate investors and investment managers with tactical and insightful investment strategies for global non-listed office real estate in multi-asset and global non-listed office real estate portfolios across various interest rate cycles, it should be noted that several assumptions and limitations of this study should be acknowledged. Specifically, this study deployed the de-smoothing approach on non-listed vehicles, with the de-smoothing parameter α = 0.5, as appraisal-based valuations tend to smooth short-term fluctuations, introducing lags that may delay the recognition of market shocks. However, the de-smoothing approach may not fully address the smoothing issues. This is the limitation that should be borne in mind. First, the de-smoothing method reduced the effective sample size, with a one-quarter data loss, which may be particularly relevant during the volatile investment periods, such as the interest rate cut cycle during the COVID-19 recession stimulus package, and the interest rate hike cycle after the COVID-19 recession stimulus package. Second, whilst the selection of the de-smoothing parameter α = 0.5 was empirically validated by model diagnostics and the stress tests on de-smoothing parameters were empirically tested to align with the baseline results, each market could be applied to varying de-smoothing parameters due to the distinctions in investment attributions across various markets and investment timeframes. Third, although this study adopted a mean-downside risk optimization framework to capture extreme downside risk, alternative approaches, such as value-at-risk (VaR) or conditional value-at-risk (CVaR), could be applied to explicitly account for tail risks and different investor risk preferences. Additionally, the deployment of alternative MAR means could be applied, despite the fact that the stress test on an alternative MAR value = 0 was performed to be consistent with the baseline results. Last, it is important to acknowledge that this research relies heavily on private real estate investment data, which are often limited. Due to the less transparent nature of this market, where assets are infrequently traded, comprehensive and consistent data coverage is not always available, thus limiting the robustness of certain analyses. These gaps can be seen across several sub-sector indices and time periods, and are acknowledged as a limitation of this study. Finally, while the simulated analysis highlights various practical implications, it should be noted that the findings are based on historical data and may not necessarily reflect future performance.
This study suggests that future research could explore these alternative optimization techniques to further refine portfolio allocation strategies for non-listed office real estate, particularly under periods of extreme market volatility, such as during the COVID-19 pandemic and geopolitical crises like the Russia–Ukraine war.