Time series is data collected over time, and statistical learning is a field of statistics and machine learning that develops algorithms to model and interpret this data. Together, they use statistical and machine learning models to find patterns, trends, and seasonality in data like stock prices or weather to make predictions about the future.
The LSE has a long and distinguished history in time series analysis and the Department of Statistics has a developing interest in various aspects of statistical learning. Our research in time series focuses on the development of statistical methodologies for modelling, estimation, interpretation and forecasting of time series data. Complex time series data comes in many forms and sources. Examples include low and high frequency financial or economics time series, temperature and rainfall records as functions of time (curves), and social media data as a dynamic network of users that changes its structure with time. With the advance of computing power and the complexity of data, both in volume and format, our research group is deepening its focus in statistical learning techniques that can help visualise and interpret these data.
The group has a strong link with the econometrics group in the LSE Department of Economics, which includes several eminent time series analysts. Our members also frequently collaborate with scientists around the world, exploring various problems in fields including, but not limited to, finance, economics, political science, physical science and health science. We provide external consultancy services on time series and statistical learning related projects upon request, and have previously worked with EDF, Winton Capital Management, Barclays Bank, the BBC, BrandScience, John Street Capital, GfK and Bonamy Finch.
Mona Azadkia's research is centered on advancing methodologies to analyse and quantify the dependency structure in data. Her work focuses on developing interpretable measures of dependence and conditional dependence between variables, which play a key role in various statistical tasks such as variable selection, dimensionality reduction, sensitivity analysis, causal inference, and hypothesis testing.
Yining Chen - Associate Professor
Change-point, shape constraint, computing, nonparametric, time series
Yining's current research focuses on developing new methods for statistical problems such as change-point detection and nonparametric estimation. He is also interested in understanding the computational aspects of statistical methods. He completed his PhD (2014) in Statistics at the University of Cambridge.
Please note Yining is on sabbatical for all of 2025/26.
Oliver Feng - Assistant Professor
Nonparametric and shape-constrained inference, approximation message passing, score matching, survival data analysis
Oliver is a Assistant Professor in Statistics, having previously been a lecturer at the University of Bath and a PhD student and postdoc at the University of Cambridge. He is interested in developing flexible theory and methodology that respect meaningful structural constraints. For instance, he has worked on shape-restricted inference problems where it may be reasonable to assume that a regression function or log-density is concave, but not that it belongs to a specific parametric family. Oliver is also exploring the applications of score matching and its links to convex optimisation. Overall, his research has a nonparametric flavour, with a particular emphasis on the robustness of statistical procedures to outliers and model misspecification. Oliver has also been involved in some interdisciplinary collaborations related to respiratory illnesses and the career intentions of medical students.
Piotr Fryzlewicz - Professor
Time series, change-points, multiscale methods, causality, machine learning
Piotr Fryzlewicz's research interests lie in multiscale modelling and estimation, time series (especially nonstationary time series), change-point detection, high-dimensional statistical inference and dimension reduction, statistical learning, networks, functional programming in data science, statistics in finance, statistics in the social sciences, and statistics in neuroscience. Amongst others, Piotr is the originator of the Haar-Fisz transformation and smoothing methodology for non-Gaussian data and the Wild Binary Segmentation method for multiple change-point detection, as well as having co-authored work on Sparsified Binary Segmentation for high-dimensional time series segmentation and tilted correlation for variable selection in high-dimensional regression models.
In 2013, Piotr was awarded a Guy Medal in Bronze by the Royal Statistical Society. Prior to the LSE, Piotr worked at Winton Capital Management, the University of Bristol and Imperial College. He has a PhD in Statistics from the University of Bristol, awarded in 2003.
Kostas’ research focuses on developing and applying advanced computational methods, such as Markov Chain and Sequential Monte Carlo, for Bayesian Inference. His methodology has mostly targeted continuous time probability models based on stochastic differential equations driven by standard or fractional Brownian motion. The areas of application include Financial and Econometric Time Series as well biomedical problems such as stochastic epidemic models and analysis of growth curves.
Prior to joining the Statistics Department of LSE, he was a post-doctoral researcher at the University of Cambridge, in the Signal Processing Laboratory of the Engineering Department. He completed his PhD (2007) in the Statistics Department of the Athens University of Economics and Business while spending some time at University of Lancaster.
Anica Kostic - LSE Fellow
Multiple testing, change-point detection, model selection techniques, sparse modelling and nonparametric estimation
Anica's main research interests lie in multiple testing, change-point detection, model selection techniques, sparse modelling and nonparametric estimation. She is received her PhD from LSE in 2022.
Clifford Lam - Professor
Financial time series, spatial econometrics, tensor time series, dimension reduction, factor modelling
Clifford’s research are focused in 1) statistical leaning techniques, especially for high dimensional data, and 2) time series analysis. These include semiparametric modelling, variables and feature selection, regularization methods for high dimensional time series analysis, to name but a few areas. One particular area of interest is the estimation of a large covariance/precision matrix from data. With random matrix theories more developed over the past decade, it is a high time for further developments of theories and methodologies in the area of high dimensional matrix estimation and applications. This area is important in a wide variety of scientific fields, including portfolio allocation and risk assessment in finance, classification and large scale hypothesis testing in bioinformatics, forecasting in macroeconomics time series, or cosmological survey in astrophysics.
High dimensional time series modelling is needed nowadays for making sense of vast volume of data we can find everyday around us, including the internet. Clifford Lam’s one particular research interest about high dimensional time series analysis is to find "factors" that can explain/summarise a majority of time series dynamics, like market factors that explain the dynamics of most stock prices in FTSE 100. A goal is to incorporate large number of variables that we can observe, and then summarise these into factors for increasing the explanatory and predictive power of various time series models.
Another area of research is in spatial econometrics modelling. A commonly used model is the spatial lag/error model for a large spatial panel of time series. To be able to use such a model, a component called the spatial weight matrix, which is a square matrix of the same size as the dimension of the panel, has to be pre-specified. This matrix represents the underlying spatial interdependence structure of the data. Yet there are no universal rules in doing so, and most practitioner use certain distance metrics to specify such a matrix, which is at best a crude approximation to the said structure. Moreover, when the dimension of the panel increases, it becomes more difficult to specify this spatial weight matrix. There are in fact various ways to estimate the said matrix from data, and inference in the models with such a matrix estimated rather than pre-specified is also an important research element.
Prior to joining the LSE in 2008, Clifford was a PhD student in the department of Operations Research & Financial Engineering, Princeton University.
Xinghao Qiao - Associate Professor
Functional data analysis, functional time series, high-dimensional time series, high-dimensional statistical inference, large-scale multiple testing
Xinghao’s research is focused on (i) functional and longitudinal data analysis, (ii) high dimensional statistical inference, e.g. covariance and precision matrix estimation, variable selection, (iii) time series analysis, e.g. functional time series, high dimensional time series, (iv) statistical machine learning with applications in Business, Neuroimaging Analysis and Environmental Sciences.
Prior to joining the LSE as an Assistant Professor in Statistics, Xinghao earned his PhD in Business Statistics from Marshall School of Business at the University of Southern California, M.S. in Statistics at the University of Chicago and B.S. in Mathematics and Physics at Tsinghua University.
Tengyao Wang - Professor
High-dimensional data, change point analysis, sparse signal detection, robust statistics, dimension reduction
Tengyao Wang is broadly interested in the area of high-dimensional statistics. His research focuses mainly on developing computationally efficient procedures for high-dimensional problems, while at the same time understanding the potential statistical limitations imposed by computational constraints. Some of his current research interests include: (i) Sparse signal detection in high-dimensional data; (ii) Change-point detection and estimation problems; (iii) Dimension reduction techniques; (iv) Robust statistical procedures in the presence of missing data or heavy-tailed noise; (v) Nonparametric statistical inference and (vi) Applications, including medical statistics, financial data analysis and statistical learning-assisted material discovery.
Prior to joining LSE as an associate professor, Tengyao was a lecturer at University College London and a research fellow at Cantab Capital Institute for the Mathematics of Information, University of Cambridge. Tengyao was awarded the Royal Statistical Society Research Prize in 2019 and the Guy Medal in Bronze in 2023.
Qiwei Yao - Professor
High-dimensional time series analysis, dimension reduction and factor modelling, dynamic network, spatio-temporal processes, nonstationary processes and cointegration
Professor Yao's recent research has mainly (but not exclusively) focused on analysing complex and high-dimensional time series in the sense that the observation recorded at each time is more complex than a single scalar or a short vector. Two examples under this framework are spatio-temporal data and dynamic network for which the observation at each time is a space or a network. Demand for analysing those data on an ever-increasing scale is a part of the real challenge underneath the buzzword BigData. The time series thinking and methodology can contribute in facing those challenges. An overarching aim has been to develop new tools which reduce the dimension and/or the complexity of time series by exploring latent low dimensional structures.
He has also published in the areas of nonlinear time series, functional time series, econometrics, extreme values of dependent data, non/semi-parametric estimation for conditional distributions, non/semi-parametric regression. Take a look at a full list of publications.
With the increasing experience in research and, especially, in solving practical problems arising from consultancy, Professor Yao is more attracted to the pursuing for the simplicity in statistical methodology, as simple methods are often effective, and gain more appreciation in application. With the ever-increasing data size and complexity in this information age, the challenge is to develop simple, if ever possible, statistical methods relevant to solving new and complex practical problems.
Please note Qiwei is on sabbatical for all of 2025/26.
Research students
Kaixin Liu Research interests: Time series analysis, focusing on high-dimensional time series, tensor time series, non-linear time series, high-frequency time series
Olga Lupova Research interests: Time series, deep learning
Di Su Research interests: Change point detection, statistical learning, and asymptotic variance estimation
Yutong Wang Research interests: High-dimensional time series, dynamic networks, statistical learning theory
Xianghe Zhu Research interests: Network analysis, hypergraphs and dynamic networks