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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

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48 results for Factored Policies

FACMAC combines deep policy gradients with factored critic for multi-agent reinforcement learning.

problem Cooperative multi-agent reinforcement learning in discrete and continuous action spaces.
method FACMAC uses a centralised but factored critic, combining per-agent utilities into a joint action-value function.
result FACMAC outperforms MADDPG and other baselines on multi-agent particle environments and StarCraft II tasks.

This paper studies optimal approximation factors in misspecified off-policy RL, identifying key factors under various settings.

problem Understanding optimal approximation factors in misspecified off-policy value function estimation.
method Examined various settings including weighted L2L_2-norm, LL_\infty norm, state aliasing, and state coverage.
result Established optimal asymptotic approximation factors for different norms and identified two instance-dependent factors for L2(μ)L_2(μ) norm.

The study examines how global economic policy uncertainty affects crude oil futures volatility.

problem Predicting crude oil futures volatility using global economic policy uncertainty.
method Established single-factor and two-factor models under the GARCH-MIDAS framework, tested with rolling-window and fixed-span specifications.
result GEPU changes have stronger predictive power than the GEPU index for crude oil futures volatility.

Scarce data is a major challenge to scaling robot learning to truly complex tasks, as we need to generalize locally learned policies over different task contexts. Contextual policy search offers data-efficient learning and generalization by explicitly conditioning the policy on a parametric context space. In this paper…

2019-04-26abs ↗pdf ↗

Scarce data is a major challenge to scaling robot learning to truly complex tasks, as we need to generalize locally learned policies over different "contexts". Bayesian optimization approaches to contextual policy search (CPS) offer data-efficient policy learning that generalize over a context space. We propose to impr…

2016-12-06abs ↗pdf ↗

Paper extends quantile factor analysis with probabilistic methods for better economic policy and financial condition prediction.

problem Improving accuracy in economic and financial condition prediction.
method Probabilistic quantile factor analysis with regularization and variational approximations.
result The probabilistic estimator outperforms a recent loss-based estimator in many cases.

RL learns to ignore factors in factor investing portfolios.

problem Combining factor investing and reinforcement learning for optimal portfolio allocation.
method RL agent learns through sequential allocations based on firms' characteristics using Dirichlet distributions.
result RL-based portfolios are very close to equally-weighted allocations, indicating agnostic factor learning.

Policy gradient methods with aggregated states can achieve better performance than approximate policy iteration.

problem Approximation errors in policy and value function approximations.
method State-aggregated representations and policy gradient methods.
result Policy gradient methods can achieve a per-period regret bounded by ε, while approximate policy iteration and value iteration have a higher regret.

The paper solves multi-period portfolio selection with constraints using a dynamic factor model.

problem Multi-period mean-variance portfolio selection with constraints.
method Dynamic factor model, dynamic programming, piecewise linear feedback policy.
result Optimal portfolio policies determined by two stochastic processes.

Study finds relevance of exchange and inflation rates to economic factors.

problem Determining the relevance of exchange and inflation rates to economic factors.
method Introduced concept of adequacy, established positive relation between exchange and inflation rates and other economic factors.
result Close positive relation found between exchange and inflation rates and other economic factors.

FPGs use structure to improve policy learning in complex tasks.

problem Policy gradient methods struggle with high-dimensional action spaces and objective multiplicity.
method Factor baseline and action-target influence network to reduce gradient variance.
result FPGs provide a general framework for state-of-the-art algorithms and improve performance.

Policy analysts wish to visualize a range of policies for large simulator-defined Markov Decision Processes (MDPs). One visualization approach is to invoke the simulator to generate on-policy trajectories and then visualize those trajectories. When the simulator is expensive, this is not practical, and some method is r…

2017-03-28abs ↗pdf ↗

We derive an optimal policy for adaptively restarting a randomized algorithm, based on observed features of the run-so-far, so as to minimize the expected time required for the algorithm to successfully terminate. Given a suitable Bayesian prior, this result can be used to select the optimal black-box optimization algo…

2019-02-21abs ↗pdf ↗

We propose and analyze an alternate approach to off-policy multi-step temporal difference learning, in which off-policy returns are corrected with the current Q-function in terms of rewards, rather than with the target policy in terms of transition probabilities. We prove that such approximate corrections are sufficien…

2016-02-16abs ↗pdf ↗

Paper proposes a new REINFORCE algorithm for mining formulaic alpha factors with reduced variance.

problem Mining formulaic alpha factors with interpretability and robustness in volatile markets.
method Developed a novel REINFORCE algorithm with a dedicated baseline and reward shaping.
result Boosts correlation with returns by 3.83% and enhances excess returns compared to existing methods.

Paper tackles offline RL with weak assumptions on both function classes and data coverage.

problem Achieve sample-efficient offline RL with weak assumptions on both factors.
method Simple algorithm based on primal-dual formulation of MDPs, with density-ratio function modeling dual variables.
result Polynomial sample complexity achieved under realizability and single-policy concentrability.

Study minimax off-policy evaluation in multi-armed bandits with known and unknown behavior policies.

problem Evaluate policies in multi-armed bandits with unknown behavior policies.
method Develop minimax rate-optimal procedures for known and unknown behavior policies, including the Switch estimator and Chebyshev polynomial-based estimator.
result Plug-in estimator achieves optimal competitive ratio up to a logarithmic factor when behavior policy is unknown.

Off-policy learning in dynamic decision problems is essential for providing strong evidence that a new policy is better than the one in use. But how can we prove superiority without testing the new policy? To answer this question, we introduce the G-SCOPE algorithm that evaluates a new policy based on data generated by…

2015-02-11abs ↗pdf ↗

Study classifies liability insurance policies using machine learning.

problem Classifying liability insurance policies with or without claims.
method Used machine learning models like nearest neighbour and logistic regression on Actuarial Challenge dataset.
result Models accurately classified policies into claims and non-claims groups.

It has been postulated that a good representation is one that disentangles the underlying explanatory factors of variation. However, it remains an open question what kind of training framework could potentially achieve that. Whereas most previous work focuses on the static setting (e.g., with images), we postulate that…

2017-08-03abs ↗pdf ↗

Study shows sample complexity for learning optimal policies in SSP with generative model.

problem Learning optimal policies in Stochastic Shortest Path problems.
method Derive and prove lower and upper bounds on sample complexity.
result Lower bound of Ω(SAB3/(cminε2))Ω(SAB_{\star}^3/(c_{\min}ε^2)) samples for general case, and up to logarithmic factors for bounded hitting time condition.

The paper tackles robust policy learning in MDPs using statistical methods.

problem Offline data-driven sequential decision making in MDPs.
method Evaluates policies using average rewards centered at policy-induced stationary distributions. Developed a statistically efficient method for estimating robust optimal policies.
result Established a rate-optimal regret bound up to a logarithmic factor.

This paper proposes non-stationary factor models for financial stress in the UK.

problem Managing financial vulnerabilities in the UK's complex financial system.
method Creation of non-stationary factor models to capture financial stress.
result Non-stationary factor models can better capture financial stress, especially tail events.

The paper studies how neural policies can be interpreted using decision trees.

problem Understanding how machine learning controllers make decisions in complex environments.
method The approach involves disentangled representation using decision trees to interpret neural policies.
result The paper shows that disentanglement of learned neural dynamics improves interpretability.

We study a reinforcement learning setting, where the state transition function is a convex combination of a stochastic continuous function and a deterministic function. Such a setting generalizes the widely-studied stochastic state transition setting, namely the setting of deterministic policy gradient (DPG). We firstl…

2018-07-10abs ↗pdf ↗

Recently, \citet{SuttonMW15} introduced the emphatic temporal differences (ETD) algorithm for off-policy evaluation in Markov decision processes. In this short note, we show that the projected fixed-point equation that underlies ETD involves a contraction operator, with a γ\sqrtγ-contraction modulus (where γγ is the …

2015-08-14abs ↗pdf ↗

Current economic theories miss most of economic dynamics.

problem Accuracy of economic theories and policies depend on economic variables and processes.
method Identify and analyze overlooked economic variables and processes.
result Many economic variables and processes not accounted for in current theories.

CPPO learns policies from partial offline data in MDPs with structural assumptions.

problem Offline Reinforcement Learning with partial coverage assumption.
method Constrained Pessimistic Policy Optimization (CPPO) using a function class and model class constraint.
result CPPO achieves PAC guarantee with partial coverage, learning competitive policies.

Adaptive sequential decision making is one of the central challenges in machine learning and artificial intelligence. In such problems, the goal is to design an interactive policy that plans for an action to take, from a finite set of nn actions, given some partial observations. It has been shown that in many applicat…

2019-11-09abs ↗pdf ↗

New Q-learning algorithm reduces sample complexity for large discount factors.

problem Large discount factors make Q-learning algorithms inefficient.
method Introduces a new Q-learning algorithm with uniformly bounded sample complexity.
result The new algorithm achieves asymptotic covariance that is a quadratic in 1/(1ργ)1/(1- ρ^* γ).

This paper compares two stock factor models in China's A-share market.

problem Contradicting results in existing research on stock factor models.
method Empirical analysis using China's A-share data from 2005-2020, orthogonalizing redundant factors, and 25-group portfolio returns calculation.
result The five-factor model outperforms the three-factor model in explaining excess return rates.